MADYMO Human Body Models Manual Release 7.6 April 2015

Transcription

MADYMO
Human Body Models Manual
Release 7.6
April 2015
© Copyright 2015 by TNO
All rights reserved.
MADYMO® has been developed at TASS International BV.
This document contains proprietary and confidential information of TNO. The contents of this
document may not be disclosed to third parties, copied, or duplicated in any form, in whole or
in part, without the prior permission of TNO.
The terms and conditions governing the licensing of MADYMO® software consists solely of
those set forth in written contracts between TASS International BV or TASS International
BV-authorised third parties and its customers. The software may only be used or copied in
accordance with the terms of these contracts.
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MADYMO Human Models Manual
Release 7.6
Table of contents
Table of contents ....................................................................................................... 3
1
Introduction ....................................................................................................... 6
1.1 General human body model description .................................................... 7
1.1.1 Model types ................................................................................. 7
1.1.2 Facet occupant models ................................................................. 8
1.1.3 Facet active human model............................................................ 9
1.1.4 Facet pedestrian model ................................................................ 9
1.1.5 Ellipsoid pedestrian models ......................................................... 9
1.1.6 Available human models.............................................................. 9
1.2 Model validation .................................................................................... 10
1.3 User instructions .................................................................................... 11
1.3.1 Human model files .................................................................... 11
1.3.2 Integration method and time step ............................................... 12
1.3.3 Human model positioning .......................................................... 12
1.3.4 Contacts .................................................................................... 13
1.3.5 Output ....................................................................................... 13
1.4 Examples ............................................................................................... 14
1.5 Required model licenses ......................................................................... 14
2
Facet occupant models ..................................................................................... 16
2.1 Model description................................................................................... 17
2.1.1 Anthropometry .......................................................................... 18
2.1.2 Configuration ............................................................................ 20
2.1.3 Spine and neck .......................................................................... 21
2.1.4 Thorax and abdomen ................................................................. 22
2.1.5 Pelvis ........................................................................................ 24
2.1.6 Shoulders .................................................................................. 24
2.1.7 Limbs ........................................................................................ 25
2.1.8 Skin ........................................................................................... 26
2.2.1 Blunt impact tests ...................................................................... 26
2.2.2 Sled tests ................................................................................... 28
2.2.3 Vertical vibration ....................................................................... 29
2.2.4 Child model validation .............................................................. 30
2.3.2 Positioning ................................................................................ 31
2.3.3 Contacts .................................................................................... 39
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2.4
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2.3.4 FE belt positioning and contact definition .................................. 40
2.3.5 Output ....................................................................................... 40
Examples ............................................................................................... 45
2.4.1 Frontal impact with a belt .......................................................... 45
2.4.2 Occupant model positioning method b ....................................... 45
3
Facet active human model ................................................................................ 46
3.1 Model description .................................................................................. 47
3.1.1 Anthropometry .......................................................................... 47
3.1.2 Configuration ............................................................................ 48
3.1.3 Head and neck ........................................................................... 48
3.1.4 Spine ......................................................................................... 50
3.1.6 Shoulders and arms ................................................................... 52
3.1.7 Legs .......................................................................................... 53
3.1.8 Shoes ........................................................................................ 55
3.1.9 Skin and bones .......................................................................... 55
3.1.10 Contacts .................................................................................... 56
3.1.11 Active behaviour control ........................................................... 56
3.2.1 Blunt impact and segment tests .................................................. 61
3.2.2 Sled and vehicle tests................................................................. 62
3.2.3 Vibration tests ........................................................................... 62
3.3.2 Positioning ................................................................................ 63
3.3.3 Contacts .................................................................................... 70
3.3.4 FE belt positioning and contact definition .................................. 71
3.3.5 Output ....................................................................................... 71
3.3.6 Active behaviour control ........................................................... 79
3.4 Examples ............................................................................................... 81
3.4.1 Facet mid-size male active human model settling ....................... 81
3.4.2 Facet mid-size male active human model in pre-crash and crash
phase 82
4
Facet pedestrian model ..................................................................................... 83
4.1 Model description .................................................................................. 84
4.3.2 Positioning ................................................................................ 84
4.3.3 Contacts .................................................................................... 88
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4.3.4
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Output ....................................................................................... 89
5
Ellipsoid pedestrian models .............................................................................. 95
5.1 Model description................................................................................... 96
5.1.1 Anthropometry .......................................................................... 96
5.1.2 Configuration ............................................................................ 97
5.1.3 Spine and neck .......................................................................... 98
5.1.5 Hip ............................................................................................ 98
5.1.6 Knee .......................................................................................... 99
5.1.7 Upper and lower leg .................................................................. 99
5.1.8 Ankle, foot and shoe ................................................................ 102
5.2 Model validation .................................................................................. 103
5.2.1 Blunt impact tests .................................................................... 103
5.2.2 Car-pedestrian tests ................................................................. 105
5.3 User instructions .................................................................................. 105
5.3.1 Integration method and time step ............................................. 105
5.3.2 Positioning .............................................................................. 106
5.3.3 Contacts .................................................................................. 109
5.3.4 Output ..................................................................................... 110
5.4 Example ............................................................................................... 114
5.4.1 Car-pedestrian impact .............................................................. 114
6
References ..................................................................................................... 116
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Introduction
Various types of MADYMO human body models have been developed for simulation
of the human body responses in various types of automotive applications see Table
1.1 and Figure 1.1.
Table 1.1
Human body models and applications.
Human model
Impact simulation
Comfort
Simulation
Facet occupant models
in various body sizes
Occupant crash
simulations
Prediction of vibration
transmission from the
seat through the human
body
Facet active human
model in sitting and
standing position
Occupant pre-crash and
crash simulations
Prediction of vibration
transmission from the
seat through the human
body
Ellipsoid pedestrian
models in various body
sizes
Pedestrian impact
simulations
Pedestrian impact
simulations
Pre-crash and crash impacts
Figure 1.1
Seat vibration comfort
Car-pedestrian impacts
Examples of human model applications.
The MADYMO human body models are applicable for frontal, lateral, rearward, and
vertical impact as well as intermediate impact directions and more complicated
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scenarios like rollover. Consequently, they are more biofidelic than dummy models,
which are developed for a particular loading direction. Dummy models are mostly
used for simulations of standard (regulated) impact tests. The MADYMO human
models were developed for the evaluation and optimisation of passive and active
restraint systems in a wider range of loading conditions than the standard impact tests.
The benefits of using human body models are:

Improved biofidelity compared to dummy models

Multi-directional

Scaleable to other body sizes

Biomechanical data can be easily incorporated

Modelling of post-failure (e.g. fracture) response

Inclusion of muscle activity

Inclusion of controlled posture maintenance
1.1 General human body model description
In this section, general features of the different types of MADYMO human body
models are described. Also, information is given on what models are currently
available together with general guidelines on how to use these models. Specific
features and guidelines for using the facet occupant models, the facet active occupant
model, and the ellipsoid pedestrian models are described in Chapters 2, 3, and 5,
respectively.
1.1.1
Model types
The types of MADYMO human models that have been released with MADYMO v7.5
are:
1. Facet occupant models
2. Facet active human model
3. Facet pedestrian model
4. Ellipsoid pedestrian models
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The skeleton of these human models mainly consists of chains of rigid bodies
connected by kinematic joints. The inertia properties of the rigid bodies and the
ranges of motion of the kinematic joints have been based on biomechanical data
published in literature. Joint, cardan, point and six-dof restraint models are used to
model the static and dynamic joint characteristics. The joint characteristics and
mechanical properties of the various segments of the human models are based on
biomechanical data from literature and have been tuned and validated using volunteer
and post mortem human subject (PMHS) responses in various impact tests. The
geometry, inertial and mechanical properties of the human model segments depend on
the type of model and its size.
The different human models use different outer geometry definitions. The occupant
models and the sitting active human model have been designed for accurate contact
interaction of the skin with the vehicle interior. Therefore, the outer geometry of the
occupant models is represented by facets. For pedestrian applications two different
model types are available. The ellipsoid models are fast, robust and easy to scale to
other body dimensions. These models can be used for more conceptual analysis,
preferably with an MB vehicle. For interaction with an FE vehicle, it is recommended
to use the facet pedestrian model as it has a facet geometry which allows for more
robust contact interaction with an FE environment.
1.1.2
The facet occupant models are developed and validated for impact simulation and for
simulation of vibration transmission as related to seating comfort. The outer surface
of the facet occupant models is described with meshes of shell-type massless contact
elements (further referred to as facet surfaces). These facet surfaces are fully
connected to rigid and/or flexible bodies. They allow a more accurate geometric
representation compared to ellipsoids. Although the facet surfaces are defined by FE
elements, the facet occupant models are still multi-body models, since no FE solver is
used in simulations. Inertial properties of the occupant segments are represented fully
by the inertial properties of the rigid and flexible bodies in the facet occupant model.
Deformation of soft tissues (flesh and skin) is represented by stress-based contact
characteristics defined for the facet surfaces. Using these contact characteristics in
contact definitions, soft tissue deformation is described accurately through the contact
interactions of the facet occupant model with itself and with its environment.
Structural deformation of the thoracic and abdominal area is modelled using flexible
bodies (MADYMO Theory Manual, Koppens 1988). The specific features and
guidelines of the facet occupant models are described in Chapter 2.
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Facet active human model
The facet active human model is developed and validated for pre-crash simulation,
occupant and pedestrian impact simulation and for simulation of vibration
transmission as related to seating comfort. Compared to the facet occupant model, the
neck, arms and lower extremities are modelled in more detail as well as active
behaviour to keep the initial position of the neck, spine, hips and elbows are
modelled. Besides occupant crash conditions (frontal, rear, side and vertical), the
model is suitable for pedestrian impact and low severity loading like pre-crash
braking. The outer surface of the active human model is represented by facets similar
to that of the facet occupant model. The active human model is available in two
versions, a sitting model and a standing model. The specific features and guidelines of
the facet active human model are described in Chapter 3.
1.1.4
Facet pedestrian model
The facet pedestrian mode is identical to the standing facet active human model,
except that it does not include active behaviour. This model can be used for
pedestrian impact simulations with an FE vehicle model, and is described in Chapter
4.
1.1.5
Ellipsoid pedestrian models
The outer geometry of the ellipsoid pedestrian models is represented by ellipsoids,
which provide a less accurate representation of the geometry but result in shorter
computation times than facets. The inertial properties of the pedestrian segments are
incorporated in the rigid bodies of the pedestrian models. In the ellipsoid pedestrian
models, structural deformation of flexible components is lumped in kinematic joints
in combination with dynamic restraint models. This approach was applied in order to
simulate elastic long bone bending as well as fracture in femur and tibia. Deformation
of soft tissues (flesh and skin) is represented by force-penetration based contact
characteristics for the ellipsoids. These characteristics are used to describe contact
interactions of the pedestrian model with itself and with its environment. Inertial
properties of the pedestrian components are defined in the rigid bodies. The specific
features and guidelines of the pedestrian models are described in Chapter 5.
1.1.6
Available human models
The available occupant, active and pedestrian models are given in Table 1.2, Table
1.3 and Table 1.4 respectively. The human model files can be found in the directory
$MADHOME/share/dbs/human/3d.
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Table 1.2
Release 7.6
Occupant models.
Model name
File name
Version
Facet small female occupant
h_occ05fc
3.3
Facet mid-size-male occupant
h_occ50fc
5.2
Facet large male occupant
h_occ95fc
1.8
Facet 1.5-year-old child occupant
h_occ1_5yfc
1.6
Facet 3-year-old child occupant
h_occ3yfc
1.6
h_occ6yfc
2.3
h_occ10yfc
1.6
Scalable facet mid-size male occupant
h_occ50fc.par
4.11
Scalable facet small female occupant
h_occ05fc.par
2.11
Model name
File name
Version
Facet mid-size male active human model in sitting
position
h_act50fc_sitting
1.2
Facet mid-size male active human model in
standing position
h_act50fc_standing
1.2
Model name
File name
Version
Facet mid-size male pedestrian
h_ped50fc
3.0
Ellipsoid 3-year-old child pedestrian
h_ped3yel
5.1
h_ped6yel
5.1
Ellipsoid small female pedestrian
h_ped05el
5.1
Ellipsoid mid-size male pedestrian
h_ped50el
5.1
Ellipsoid large male pedestrian
h_ped95el
5.1
Ellipsoid scalable mid-size-male pedestrian
h_ped50el.par
5.1
Table 1.3
Table 1.4
Active human models.
Pedestrian models.
1.2 Model validation
TNO puts much effort into validating its MADYMO human body models for a wide
range of loading conditions. The human models have been validated extensively on
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segment as well as full body level with volunteer (low to mid severity impact) as well
as PMHS test data (mid to high severity impact). For segment validation static as well
as dynamic tests have been used for full body only dynamic tests. Model parameters
that have a wide range in the literature and model parameters that could not be found
in the literature have been tuned with these validation tests. A review of segment
impact and full body impact test data used for model validation is given for each type
of human model in the corresponding chapter.
1.3 User instructions
The ‘user instructions’ sections of the corresponding chapters in this manual describe
how to handle the human models model-specific. In this section, information is given
to guide users through implementing human models in their own applications.
1.3.1
Human model files
Like the MADYMO dummy models, each MADYMO human model is supplied in
two files: a user-file (<filename>_usr.xml) and an include-file (<filename>_inc.xml).
The user-file contains the human model system, in which the user-interactive human
model elements are defined and the include-file is called. The user-interactive
elements are those model elements that may need modification when applying the
human model. Besides the human model system, the user-file contains the required
control elements and a reference space system. This makes it a complete MADYMO
input deck containing the human model defined in its standard position. The user can
implement more systems, system interactions (contact definitions between different
system), loads applied to whole systems etc. in the user-file to complete the model for
a particular application.
The include-file contains the human model itself, including features like pre-defined
contact of the human model with itself. It is strongly advised not to modify any
parameters in the include-file, since this may affect the performance of the human
model. It is also recommended not to modify the BELT elements that are defined in
the facet occupant human model user-files, since these are part of these models. (For
user- and include-file architecture see also MADYMO Model Manual.)
The human models can be applied in two ways:
1. by building an ‘environment’ model around the human model in the user-file,
2. by including the human model system (the SYSTEM.MODEL element in the
user-file), accessory belts and functions in an existing ‘environment’ model input
deck.
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When calling human model output signals, or defining loads on and (contact)
interactions with the human model, reference must be made to the human model
system. This can be done by referring either to the system ID or the system NAME.
For the facet occupant and the pedestrian models, a human model can be included
more than once in an application, by making the system IDs and NAMEs unique (no
reference is made to ID or NAME inside these a human models). For the active
human model the system model has to be kept at 99, and thus only one active human
model can be used in a application. Note that the DEFINE elements used for some
human models can be included only once and hence will be identical in each human
model present in one simulation.
1.3.2
Integration method and time step
Each human model has a recommended integration method and minimum integration
time step for which it is validated and tested. The integration method and time step
are defined for each human model in the CONTROL.ANALYSIS_TIME element in
the user-file. They are also given in the ‘user instructions’ section of the
corresponding chapter in this manual.
Note that the contact stiffnesses of the modelled environment mainly determine the
time step needed, thus stiffer contacts or contact interactions with high damping
might need smaller time steps than the recommended time step of the human model.
1.3.3
Human model positioning
In order to position the human model, the INITIAL.JOINT_POS elements have to be
used. All joints that are needed for positioning the human model are defined in the
INITIAL.JOINT_POS elements in the human model user-file. Positions of all other
joints are defined in the human model include-file, and these should not be edited by
the user.
For joints of type FREE and SPHERICAL the rotational degrees of freedom should
be defined either using the R1, R2 and R3 attributes in INITIAL.JOINT_POS, or in
the related ORIENTATION elements. The defined elements use the successive
rotation method. Joints can be locked in the INITIAL.JOINT_STATUS elements.
A human model is by default positioned relative to the (global) reference space coordinate system. However, the human model can be positioned relative to a body of
another system. This can be done in the human attachment element
CRDSYS_OBJECT named ‘Human_Attachment’ and the associated orientation
‘Human_Attachment_ori’ in that element. The human attachment element
‘Human_Attachment’ is comparable to the dummy attachment element
'Dummy_attachment' in a dummy model, which is located at the H-point.
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All joints needed for human model positioning are listed in the human model
positioning tables in the ‘user instructions’ section of the following chapters. In these
tables all rotations are referred to with the terms pitch, roll and yaw (see Figure 2.7,
Figure 3.10 and Figure 5.4). The directions given in the tables refer to positive
translation and rotation directions. For all joints, the directions are defined with
respect to their co-ordinate system orientation, when the human model is in its
reference position.
The various human models each require a different positioning technique. These
techniques are explained in the ‘user instructions’ section of the corresponding
chapters.
1.3.4
Contacts
All contacts with the human model itself are already included in the model includefile. The user has to define the external contact interactions between the human model
and its environment. To facilitate this, the human models have pre-defined contact
groups that can be used directly in the external contact interactions. These pre-defined
contact groups are available for all relevant human model components. Note that
these contact groups do not necessarily include all ellipsoids/elements/nodes of the
components, but are defined such that the relevant outer surface is covered. Model
specific information on these contact groups is given in tables in the corresponding
chapters. It is recommended to define contact only if it is really needed, in order to
avoid an unnecessary increase in calculation time. As a start for a simulation, the
most proper way is to define contact only where it is expected. Thereafter, the contact
assumptions should be checked, and necessary corrections and/or refinements can be
made. Some general guidelines for contact definitions can be found in the MADYMO
Theory Manual and the MADYMO Reference Manual.
1.3.5
Output
The most relevant output signals and injury criteria are predefined in the human
model include-file. All output signals are defined corresponding to the orientation of
the body. Output signals are as far as possible filtered according to the SAE J211/1
sign convention. In order to avoid problems with filtering of output signals, it is
recommended to use an output time step of at least 1.0E-04 s (TIME_STEP under
CONTROL_OUTPUT).
Output of the human model is called in the user-file. This is done in the
TIME_HISTORY.MB element inside the CONTROL.OUTPUT element. The user
can place these names in the elements inside the TIME_HISTORY.MB element in
order to obtain these output signals.
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To obtain injury criteria output, all the output signals that are used for that criterion,
must be called in the CONTROL_OUTPUT element. Model specific information on
the output signals and injury criteria is given in the tables in the ‘user instructions’
section in the corresponding chapter.
1.4 Examples
For each type of human model, one or more examples of an (validation) application
are described in this manual. An overview of the available example application files
of the human models is given in Table 1.5.
Table 1.5
Example application files.
Application model
File name
Version
Positioning of the facet mid-size male occupant
model, method b
e_occ50fc_pos_b 1)
1.4.2
Frontal impact of the facet mid-size male occupant
model
e_occ50fc_imp 1)
1.6
Facet mid-size male active human model settling
e_act50fc_settling 2)
2
1.0.1
Facet mid-size male active human model in precrash and crash phase
e_act50fc_precrash )
1.1
Lateral impact of the mid-size male pedestrian
model
e_ped50el 1)
1.3
1
) Available in the directory $MADHOME/share/appl/3d.
) Available on the TASS website (www.tassinternational.com).
2
1.5 Required model licenses
Table 1.6 lists the required license module name for each of the MADYMO Human
models. The listed modules are in additions to the MADYMO /Solver Multibody and
MADYMO/CPU licenses that are always required to run MADYMO models.
Ellipsoid and facet models do not require a MADYMO /Solver FEM license. Scalable
models will need a SCALER license in order to generate a scaled version of the
model.
Table 1.6
Human body models and required licenses.
Human Body model name
License
Facet 1.5-year-old child occupant
MADYMO/ Human Models/ Full Body Child
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Facet small female occupant
MADYMO/ Human Models
Facet mid-size male occupant
Facet large male occupant
Scalable facet mid-size male occupant
Scalable facet small female occupant
MADYMO/ HumanActive
Facet mid-size male pedestrian
MADYMO/ Human Models/ Pedestrian
Ellipsoid small female pedestrian
Ellipsoid mid-size male pedestrian
Ellipsoid large male pedestrian
Scalable ellipsoid mid-size male pedestrian
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The MADYMO facet occupant model described in this chapter is currently released
in seven body sizes. A small female model representing the 5th percentile female
population, a mid-size male model representing the 50th percentile male model
population, and a large male model representing the 95th percentile male model are
available (Figure 2.1). Four child body sizes representing a 1.5, 3, 6 and 10-years-old
are available (Figure 2.2). Please, note that the child occupant models are scaled from
adult anthropometries and hence they do not necessarily represent children in terms of
their biofidelic behaviour.
Figure 2.1
16
Adult size facet occupant models from left to right; large male, mid-size male
(middle), and small female (right).
Figure 2.2
Release 7.6
Child facet occupant models from left to right; 1.5, 3, 6 and 10-year-old.
2.1 Model description
The MADYMO model names and input file names of the facet small female occupant
model, the facet mid-size male occupant model and the large male facet occupant
model are:
Facet small female occupant:
h_occ05fc_usr.xml
h_occ05fc_inc.xml
Facet mid-size male occupant:
h_occ50fc_usr.xml
h_occ50fc_inc.xml
Large male facet occupant:
h_occ95fc_usr.xml
h_occ95fc_inc.xml
The MADYMO model names and input file names of the child occupant models are:
1.5-year-old child:
h_occ1_5yfc_usr.xml
h_occ1_5y fc_inc.xml
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3-year-old child:
h_occ3yfc_usr.xml
h_occ3y fc_inc.xml
6-year-old child:
h_occ6yfc_usr.xml
h_occ6y fc_inc.xml
10-year-old child:
h_occ10yfc_usr.xml
h_occ10y fc_inc.xml
Besides these models, a scaleable facet male and female human occupant model are
available:
Parameter model mid size male:
h_occ50fc.par
Parameter model small female:
h_occ05fc.par
Using the MADYMO/SCALER utility, these models can be scaled towards different
anthropometry data sets. It is recommended, to use the male model to create male and
child models and to use the female model to create adult or teenage female models.
A target model anthropometry can be created either by defining an anthropometry
data set of 35 values, by defining 14 x 4 fixed scale factors or by using the GEBOD
database. Additional to the geometric properties, the following mechanical properties
are also scaled towards the target anthropometry: mass, inertia, stiffness and contact
characteristics. Several anthropometrically extreme models, ranging from small
children to large adults, have been created using the 3 possible methods. The
definition of the anthropometry values and the fixed scaling factors produced
acceptable scaled models, whereas the GEBOD database sometimes generated
models with unacceptable deviations, especially when scaling towards children.
The main limitation of the scalable models is that no age based material dependency
is taken into account during the scaling. As a result, the response of the child models
is not completely biofidelic. Furthermore, the impact behaviour (injuries, range of
motion, etc.) of all models other than the base model has not yet been validated.
2.1.1
2.1.1.1
Anthropometry
Adults
The anthropometry of the adult facet occupant models has been obtained from the
database of the RAMSIS software package (RAMSIS 1997). The Western European
population aged 18 to 70 years of 1984 was used. For the facet mid-size male
occupant model simply medium typologies were selected for height, weight and
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sitting height. For the small female a very short and very slim model was selected in
RAMSIS. The resulting body mass and sitting height were considered to be somewhat
extreme also in comparison to the small female Hybrid III crash dummy. This was
resolved in a second step using the BODYBUILDER submodule of RAMSIS. The
proportion and corpulence have been adapted by modification of the percentile values
of their related key parameters, respectively sitting height and waist circumference.
For the sitting height the percentile value was changed from 2.2% to 5.0%, the waist
circumference changed from 14.9% to 18.0%. The same procedure was followed to
create the large male occupant model. In the first step a very tall subject with a large
waist was selected in RAMSIS, however the resulting body mass was somewhat high
and the standing height and sitting height were considered too low. Therefore, the
BODYBUILDER module was used in a second step with the standing height, the
sitting height and the body mass as key parameters. In Table 2.1 the resulting
anthropometry of the facet occupant models is described. Note that the large male
occupant model with an erect sitting height of 1.00 m is considerably taller than the
95th percentile Hybrid III, which has an erect sitting height of only 0.935 m.
Table 2.1
Anthropometry of the adult facet occupant models.
Parameter
Small female
Mid-size male
Large male
Standing height [m]
1.52 m
1.74 m
1.91 m
Sitting height [m]
0.81 m
0.92 m
1.00 m
Weight [kg]
49.8 kg
75.7 kg
101.1 kg
The mass distribution of the facet occupant models is based on the RAMSIS database.
Rotational inertia was derived by integration over the segment volume, where for
each segment a homogeneous density was assumed. The neck rotational inertia has
slightly been increased to allow larger time steps for the MADYMO calculations.
2.1.1.2
Children
The child models anthropometries were based on the CANDAT database (Twisk
1993). This database was developed within TNO and used for determination of the
anthropometry of the Q-series of dummies. The child human models therefore
represent an identical anthropometry as the Q-dummies.
The scaling of the child occupant models from the adult occupant models was done
using MADYMO/SCALER (Happee et al., 1998). In MADYMO/SCALER different
scaling factors are specified for x-, y-, and z-dimensions and for different body parts.
Thus the model geometry can be adapted freely to the desired anthropometry
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parameters. In addition to the geometry, all other model parameters can be scaled.
Based on the desired anthropometry parameters there is scaling of:

Geometry

Mass and moments of Inertia

Joint characteristics (stiffness, friction, damping and hysteresis), including that of
protected joints

Ellipsoids and penetration characteristics

Force models

Fracture levels

Sensor locations
Besides these properties, the child occupant models are identical to the adult occupant
models. The differences exisiting in material properties between tissues of adults and
children, as well as developmental stages of development of various organs have not
been taken into account in the current models. The anthropometry of the child
models, obtained with scaling is shown in Table 2.3.
Table 2.3
Anthropometry of the facet child occupant models.
Parameter
1.5-year-old
3-year-old
6-year-old
10-year-old
Standing height [m]
0.81
0.95
1.16
1.44
Sitting height [m]
0.50
0.55
0.63
0.75
Weight [kg]
11.0 kg
14.5 kg
21.0 kg
35.5 kg
2.1.2
Configuration
The occupant models each consist of 92 bodies. The first branch connects the head
and vertebral bodies to the pelvis. The second and third branch connects the bodies of
the left and right leg to the pelvis, respectively. The fourth and fifth branch connects
the fingers to the shoulders, respectively. The thumb is connected to the mid-hand
joint on a separate branch from the fingers. The thorax and the abdomen each consist
of 4 flexible bodies that divide the thorax and abdomen in horizontal slices. Attached
to each slice at the left and right side and at the front, bodies have been placed for
20
Release 7.6
attachment of force models. The thorax and abdomen bodies are divided over 3
branches (front, left and right) for each slice.
2.1.3
2.1.3.1
Spine and neck
General
The lumbar, thoracic and cervical spine is modelled in such a way that it gives a
biofidelic response in a wide range of loading conditions. The vertebrae are described
by rigid bodies connected by free joints with lumped joint resistance (restraint)
models. The geometries of the lumbar and thoracic vertebrae are each described by a
single ellipsoid. The geometries of the cervical vertebrae are extended with ellipsoids
representing the transverse processes and spinal processes.
The spine and neck translational and rotational resistance has been implemented using
non-linear lumped joint resistance (restraint) models. Parameters were based on
literature data (Prasad & King 1974, Kapandji 1974, Yamamoto et al. 1989, Schultz
et al. 1979, Berkson et al. 1979, Markolf 1972, Panjabi 1994, Jager 1996,
Kroonenberg 1997). These joint resistance models describe the dynamic response of
the intervertebral discs, ligaments and effects of muscular resistance in a global way.
The spine model has been validated statically and dynamically with both PMHS and
volunteer tests.
The neutral position of the spine in the facet occupant models represents the spinal
curvature of an erect standing person. In Figure 2.3 the spine and neck model with the
origins of the vertebral joints are shown.
21
Figure 2.3
2.1.4
Release 7.6
Spine and neck in frontal and lateral cross-sectional view. The co-ordinate
systems indicate the origins of the vertebral joints.
Thorax and abdomen
In an impact loading case the human thorax and abdomen can deform in a complex
3D manner due to contact but also due to spinal deformations. This has been
modelled by using flexible bodies (see MADYMO Theory Manual and Koppens
1988). The flexible bodies describe 3D deformations with only a few degrees of
freedom and are therefore efficient. The flexible bodies describe global deformations
while the contact algorithm describes local deformation. The resulting capability to
model torso deformation was found to correspond with experimental data.
The thorax and the abdomen each consist of 4 flexible bodies. The flexible bodies
divide the thorax and abdomen in horizontal slices, as is shown in Figure 2.4. The
geometry of the flexible bodies is determined by the position of the skin nodes of the
flexible body in concern. A point mass is assigned to each node.
22
Release 7.6
thorax flexible body 4




abdomen flexible body 4 
Figure 2.4
Right view of the facet active human model with the arrows pointing to the
flexible bodies, and the rigid bodies shown as green dots.
The flexible bodies are each connected to the closest rigid vertebral body of the spine.
Each flexible body is able to deform in 3 predefined deformation modes: 1 frontal
mode and 2 lateral modes (left and right). The modes were determined analytically as
linear functions of the co-ordinates of the nodes. The frontal mode contains both xand y-displacements, the lateral modes only contain y-displacements. The input
options for the flexible bodies only allow linear stiffness and damping, which is not
sufficient for describing the demonstrated non-linear behaviour of the torso in impact.
Therefore, point restraints were added for modelling the frontal and lateral stiffness
and damping of the flexible bodies, and the stiffness and damping in all modes were
set to negligible low values (setting these values to zero is not allowed in
MADYMO).
For attachment of the point restraints rigid bodies were added: 1 frontal, 1 left and 1
right of each flexible body. These rigid bodies are connected to the skin nodes of the
23
Release 7.6
flexible body. The point restraints at the frontal bodies and the lateral bodies only
contribute to loading in the x-direction and y-direction, respectively. Coupling
between frontal and lateral deformation is taken into account by the frontal
deformation mode.
Vertical point restrains were added between the rigid bodies of each flexible body.
These point restraints do not only have a z-component, but also have a small x- or ycomponent for frontal respectively lateral stiffness. This was done in order to obtain a
more realistic skin deformation.
The two lowest flexible bodies also model the iliac wings. Since no biomechanic data
was available the resistance for frontal loading of these two lowest flexible bodies is
based on a model of the Hybrid III 50th percentile dummy.
2.1.5
Pelvis
The pelvis bone is modelled by facets. The facet pelvis can be used in contact with
the environment. For example in a frontal impact simulation with a lap belt defining
contact between the belt and the skin and the facet pelvis will result in a more realistic
occupant response than with skin only.
2.1.6
Shoulders
The shoulder forms a moving base for the upper extremity. It consists of a number of
joints connecting the humerus, scapula, clavicle and sternum. Furthermore, the
scapula contacts the back of the thorax; it can glide over the scapulothoracic gliding
plane. This connection makes the shoulder a closed chain mechanism. In the facet
occupant models the clavicle, scapula and humerus are described by rigid bodies
connected by spherical joints. The geometry of the clavicles is represented by
cylinders, the geometry of the scapulae is represented by simple triangular elements,
as is shown in Figure 2.5.
The joint characteristics are based on biomechanical data from Engin (1984). The
clavicles and the sternum deform during shoulder loading. In the model such
deformations are incorporated by force models, which allow translational degrees of
freedom between the clavicle and sternum. The translational deformation
characteristics are based on PMHS axial clavicle loading experiments as well as finite
element simulations of clavicle and rib cage loading.
In the real human body, the scapula contacts the thorax. Active muscle force is
needed to maintain this contact and to stabilise the shoulder girdle. These complex
interactions between shoulder and thorax are modelled as a set of passive force
models. The scapula is supported on the spine by point restraints to T1 and T9. Thus,
24
Release 7.6
the load transfer from shoulder to spine is modelled by the skeletal connection
(scapula-clavicle-sternum-ribs-spine) and by these additional force models. The
resulting resistance of the shoulder model was verified against published quasi-static
volunteer test data as well as lateral impact data.
Figure 2.5
2.1.7
The shoulder model in frontal cross-sectional view. The co-ordinate systems
indicate the origins of the scapula joints, acromio-clavicular joints and
glenohumeral joints.
Limbs
The segments of the upper and lower limbs are all described by rigid bodies
connected by spherical joints. In impact conditions some passive bending is possible
in all rotational directions of all real human joints. Therefore, degrees of freedom, in
which voluntary movement is not possible, are also included. The ranges of motion
(R.O.M.) of the different limb joints have been based on RAMSIS. Modelling has
been done by defining cardan or flexion torsion restraints with non-linear stiffness
functions. The resistance parameters are based on literature data on passive human
joint properties (Engin et al. 1979-1989, Kapandji 1974, Ma et al. 1995).
The arm model contains 3-segment thumbs and a 3-segment description of the
combined fingers. The joints of thumbs and fingers have been locked, making the
hands rigid. The leg model contains a 3-segment description of the foot. The joints
between the metatarsals (midfoot) and the foot have been locked. The outer geometry
25
Release 7.6
of the feet has the form of shoes. The geometry of these shoes is from GINO shoe
models and has been obtained from RAMSIS.
2.1.8
Skin
The outer surface of the facet occupant model (skin) is described by a mesh of
triangular elements defined as a null material. The skin is divided into several
sections that are supported on the nearest bodies. In the thorax and abdomen area the
skin is supported by flexible bodies. Different parts of the skin have different contact
characteristics, based on validation.
The facet mid-size male occupant model has been validated extensively for impact
loading as described by de Lange et al. (2005). Two major categories of tests were
conducted: volunteer tests for low severity loading and post mortem human substitute
(PMHS) tests for higher severity loading. The facet small female occupant model has
been validated as described in Happee et al. (2000a) using published small female
impactor corridors for the SID2s dummy (Daniel et al., 1995) and some other small
female PMHS tests. In sections 2.2.1 and 0 the blunt impactor tests and the sled tests
that were used for the validation are described. The facet mid-size male occupant
model has also been validated for vertical vibration, see section 2.2.3.
Implementations of typical validation tests are described in the ‘examples’ section.
The child human models are compared with corridors that were scaled based on a
method developed by Irwin & Mertz (1997). While the child models are merely
scaled adults, without a correct implementation of child specific structural and
material differences, they are not validated models but research models.
2.2.1
Blunt impact tests
Blunt impact tests used for the validation of the facet occupant model are summarised
in Table 2.5. The modelled impactors of the various segment tests are all shown
together with the male facet occupant model in Figure 2.6.
26
Figure 2.6
Release 7.6
Frontal impactor locations (thorax, abdomen) and lateral impactor locations
(shoulder, thorax, pelvis).
27
Table 2.5
Release 7.6
Blunt impact and drop tests used for validation of occupant models.
Model
Test
Reference
Segment
Description
Test
object
Specifications
Small female
shoulder
1 lateral impact
PMHS
4.5 m/s, 14.0 kg
Daniel et al. (1995)
Small female
thorax
2 lateral impact
PMHS
4.3, 6.7 m/s, 14.0
kg
Daniel et al. (1995)
Mid-size male
head
2 frontal impact
PMHSs
2.0, 5.5 m/s
Don et al. (2003)
2 lateral drop
PMHSs
2.0, 5.5 m/s
ISO TR9790 (1997)
Mid-size male
shoulders
4 lateral impact
PMHSs
4.5-7 m/s
ISO TR9790 (1997), Meyer et
al. (1994), Lizee et al. (1998)
Mid-size male
thorax
8 frontal impact
PMHSs
3.4–9.9 m/s,
10.4–23.4 kg
Bouquet et al. (1994),
Neathery (1974), Kroell et al.
(1971, 1974, 1976), Nahum et
al. (1970,1975)
4 lateral impact
PMHSs
3.3-6.7 m/s,
23.0-23.4 kg
Lizee et al. (1998), Talantikite
et al. (1998), ISO TR9790
(1997)
2 rigid drop
tests
PMHS
4.5, 6.3 m/s
ISO TR9790 (1997)
3 frontal impact
PMHSs
6.1-10.4 m/s,
18.0-63.6 kg
Cavanaugh (1986), GESAC
(2001), Don et al. (2003)
2 rigid drop
tests on armrest
PMHSs
4.5, 6.3 m/s
ISO TR9790 (1997)
6 lateral impact
PMHSs
3.5-10.0 m/s,
17.3-23.4 kg
Bouquet et al. (1994), ISO
TR9790 (1997)
2 rigid drop
tests
PMHSs
3.2, 4.5 m/s
ISO TR9790 (1997)
Side airbag
deployment
PMHSs
Mid-size male
abdomen
Mid-size male
pelvis
Small female
2.2.2
Happee et al. (2000a)
Sled tests
Sled tests used for the validation of the full body behaviour of the facet occupant
models are summarised in Table 2.6.
28
Table 2.6
Release 7.6
Sled tests used for validation of the full body behaviour of the facet occupant
models.
Model
Test
Reference
Description
test object
specifications
Mid-size male
9 frontal rigid
seat sled tests
5 volunteers
15 G peak
Thunnissen (1995)
Mid-size male
2 rear deformable
seat sled tests
2 volunteers
4-5 G peak
Kroonenberg et al. (1998)
Mid-size male
9 rear rigid seat
sled tests
9 volunteers
3.6 G peak
Ono et al. (1999)
Mid-size male
9 rear deformable
seat sled tests
9 volunteers
3.6 G peak
Ono et al. (1999)
Mid-size male
6 rear rigid seat
sled tests
3 PMHS
9-12 G peak
Bertholon et al. (2000)
Mid-size male
Lateral rigid seat
sled test
volunteer
6.7 G peak
Ewing (1972)
Mid-size male
Lateral rigid seat
sled tests
PMHSs
20, 37 G peak,
6.8, 8.9 m/s
Happee et al. (2000a),
ISO TR9790 (1997)
Mid-size male
oblique rigid seat
sled test
volunteer
11 G peak
Philippens et al. (2004)
2.2.3
Vertical vibration
Vertical vibration tests used for the validation of the full body behaviour of the midsize-male facet occupant model are summarised in Table 2.7.
Table 2.7
Vertical vibration tests used for validation of mid-size male occupant models.
Model
Test
Reference
Description
Test object
Specifications
Facet mid-size
male occupant
Vibration tests on
rigid seat
11 volunteers
0.5-15 Hz, 0.4 G
peak
Verver et al. (2003)
Facet mid-size
male occupant
Vibration tests on
standard car seat
11 volunteers
0.5-15 Hz, 0.4 G
peak
29
2.2.4
Release 7.6
Child model validation
The dynamic hub impactor tests of Neathery (1974) were simulated with all child
occupant models. The impactor mass and diameter were scaled according to the Irwin
& Mertz (1997) scaling method. An overview of the various simulations is given in
Table 2.8. Additional data used to validate the 6 year old child model are summarized
in Table 2.9.
Table 2.8
Hub impactor tests used for assessment of performance of child occupant
models.
Model
Test
Reference
Description
Test object
Specifications
1.5-year-old
Hub impactor
test
Scaled
corridor
2.9 kg, 4.3 and 6.7
m/s
Neathery (1974)
Irwin and Mertz (1997)
3-year-old
Hub impactor
test
Scaled
corridor
3.8 kg, 4.3 and 6.7
m/s
Neathery (1974)
6-year-old
Hub impactor
test
Scaled
corridor
5.3 kg, 4.3 and 6.7
m/s
Neathery (1974)
10-year-old
Hub impactor
test
Scaled
corridor
10.0 kg, 4.3 and
6.7 m/s
Neathery (1974)
Table 2.9
Additional datasets used for validation of the 6 year old child model
Model
Test
Reference
Description
Test
object
Specifications
6-year-old
Frontal thoracic
pendulum
5 PMHS
3.5 kg, 6 m/s
Ouyang et al (2006)
6-year-old
Abdominal belt
loading test
47 porcine
2 locations, 3 rates
Kent et al (2006)
6-year-old
Neck tension
test
9 PMHS
Quasi static
Ouyang et al. (2005)
30
Release 7.6
2.3.1
The recommended integration method and minimum integration time step for the
facet occupant models is given in Table 2.10.
Table 2.10
Recommended integration method and time step for the facet occupant models.
Model
Integration method
Time step (s)
Small female
EULER
≤1.0E-05
Mid-size male
EULER
≤1.0E-05
Large male
EULER
≤1.0E-05
2.3.2
Positioning
Because of the flexibility of the facet occupant model’s spine and neck, it is a bit
more complex to position this model in a seat than a dummy model. The occupant
model must be in an equilibrium state at the start of a simulation. Otherwise, initial
accelerations will take place. A pre-simulation is generally required to obtain this
equilibrium. Positioning of the facet occupant model is done in four steps:
1. The complete occupant model is positioned and orientated correctly with respect
to its environment by initialising the position and orientation of the human joint
(Human_jnt). Vertebrae can be orientated in order to put the spine in a seating
position. The occupant model can best be positioned just above the seat with its
pelvis at the correct horizontal position. In a relaxed seating position the human
spine is curved differently than in a standing position or a straight seating
position. To model a relaxed seating position the vertebral joints of the facet
occupant
model
can
be
rotated
in
the
user-file
in
ORIENTATION.SUCCESSIVE_ROT. To put the spine of the facet occupant
model in a relaxed seating position the initial vertebral joint rotations should be
changed to the values given in Table 2.11 (seating position according to
Davidsson et al. (1998)).
2. The extremities are orientated with respect to the parent component by changing
the orientation of the joints in the positioning elements (INITIAL.JOINT_POS).
The occupant can for example be put in a driving position.
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Release 7.6
3. A pre-simulation is performed in which the facet occupant model is put into the
seat by a gravitational field only (acceleration field of -9.81 m/s2 in z-direction).
The run time for positioning the facet occupant model needs to be large enough
for the occupant to find its equilibrium (typically about 1 s). To maintain the facet
occupant model in an upright position when subjected to gravity, several methods
can be used. Depending on the situation a different positioning is preferred. In
case of simulations of live human behaviour, the active human model is
recommended (see Chapter 2). For PMHS tests, there are two options: however
one likes to simulate a certain test, one should take into account the way the
PMHS was settled. For example, if the PHMS was kept upright with an
electromagnet attached to the top of his head, option a should be used. Option b is
preferred for general simulations of PMHS behaviour.
a. To keep the head upright, a support as often applied in PMHS tests can
be simulated by defining a point-restraint with a constant force of 100 N
in the z-direction (this compensates for the weight of the head and
vertebral masses) just above the head CG.
b. The settling of a human subject with only passive behaviour can be
simulated by defining a cardan restraint of about 1000 Nm/rad between
OC and inertial space together with a point restraint of about 1000 N/m in
the x-direction and y-direction between the head and inertial space. For
an
example
file,
see
‘e_occ50fc_pos_b.xml’
in
$MADHOME/share/appl/3d.
4. joint position degrees of freedom (JOINT_DOF) of all joints in the user-file
should be defined in the output. The joints of which the initial positions are not
defined in the user-file should be locked. The output from the last time step in the
JNTPOS file of the pre-simulation should be copied to the positioning elements
(INITIAL.JOINT_POS) of the impact simulation file. In the impact simulation
the user should remove the restraints used in the pre-simulation
When all joints in INITIAL.JOINT_POS are set to zero (except for the ankles), the
facet occupant model is in an erect standing position as is shown in Figure 2.7. This
position is called the reference position. In this position the joint translations and
rotations are defined as shown in Figure 2.7. The default position is a seating position
as is shown in Figure 2.1.
The orientations of the translational (D) and rotational (R) DOF of the facet occupant
model positioning joints are given in Table 2.14. The positioning joints are
schematically drawn in Figure 2.8.
32
Release 7.6
z
yaw left
pitch down
y
x
Figure 2.7
roll right
Definition of joint translations and rotations of the facet occupant models. The
occupant model is in its reference position.
}
}
C7-T1, …, C1-Head
Scapula-ArmUp
L5-L4, …, T2-T1
Elbow
Sacrum-L5
Human joint
Hip
Wrist
Knee
Ankle
Figure 2.8
Locations of positioning joints of the facet occupant model.
33
Release 7.6
The model contains a large number of degrees of freedom, where many of these have
only a limited range of motion. To obtain a realistic initial position care should be
taken that user-defined initial rotations and translations are within the range of
motion. Reasonable initial rotations of the limbs can be determined directly from the
ranges of motion that are specified in the cardan and flexion-torsion restraint models
of the limbs. For the neck and spine joints both initial rotations and translations can
be specified. For neck and spine the ranges of motion cannot be seen in the user-file
nor in the include-file, since the joint resistance models are protected. Therefore,
some information on the range of motion is given in Table 2.12 and Table 2.13.
34
Table 2.11:
Release 7.6
Vertebral joint rotations in a relaxed seating position according to Davidsson et.
al. (1998).
Joint orientation
identifier
Degree of freedom
Sacrum-L5_ori
R1
0
R2
0.1021
R3
0
L5-L4_ori
0
0.0821
0
L4-L3_ori
0
0.0348
0
L3-L2_ori
0
0.0348
0
L2-L1_ori
0
0.0348
0
L1-T12_ori
0
0.0346
0
T12-T11_ori
0
0.0346
0
T11-T10_ori
0
0.0346
0
T10-T9_ori
0
0.0346
0
T9-T8_ori
0
0.0346
0
T8-T7_ori
0
0.0346
0
T7-T6_ori
0
0.0346
0
T6-T5_ori
0
0.0346
0
T5-T4_ori
0
0.0146
0
T4-T3_ori
0
0.0146
0
T3-T2_ori
0
0.0146
0
T2-T1_ori
0
0.0146
0
T1-C7_ori
0
0
0
C7-C6_ori
0
0
0
C6-C5_ori
0
0
0
C5-C4_ori
0
0
0
C4-C3_ori
0
0
0
C3-C2_ori
0
0
0
C2-C1_ori
0
0
0
C1-Head_ori
0
0
0
35
Table 2.12
Joint
Release 7.6
Joints ranges of rotations.
Minimum
motion [rad]
Torque min.
motion [Nm]
Maximum
motion [rad]
Torque max.
motion [Nm]
roll right
-0.0515
-1.5
0.0515
1.5
pitch down
-0.1707
-7.5
0.1014
1.3
yaw left
-0.0637
-1.5
0.0637
1.5
roll right
-0.0977
-10
0.0977
10
pitch down
-0.1002
-7.5
0.1225
5
yaw left
-0.3752
-1.5
0.3752
1.5
roll right
-0.105
-10
0.105
10
pitch down
-0.0473
-7.5
0.0577
5
yaw left
-0.0312
-1.5
0.0312
1.5
roll right
-0.1152
-10
0.1152
10
pitch down
-0.0701
-7.5
0.0871
5
yaw left
-0.0732
-1.5
0.0732
1.5
roll right
-0.1152
-10
0.1152
10
pitch down
-0.0628
-7.5
0.1166
5
yaw left
-0.0732
-1.5
0.0732
1.5
roll right
-0.084
-10
0.084
10
pitch down
-0.0728
-7.5
0.1166
5
yaw left
-0.0732
-1.5
0.0732
1.5
roll right
-0.0732
-10
0.0732
10
pitch down
-0.0793
-2
0.0986
5
yaw left
-0.063
-1.5
0.063
1.5
-0.042
-10
0.042
10
C0-C1:
C1-C2:
C2-C3:
C3-C4:
C4-C5:
C5-C6:
C6-C7:
C7-T1:
roll right
36
Release 7.6
Joint
Minimum
motion [rad]
Torque min.
motion [Nm]
Maximum
motion [rad]
Torque max.
motion [Nm]
pitch down
-0.0419
-7.5
0.0523
5
Yaw left
-0.021
-1.5
0.021
1.5
pitch down
-0.036
-48
0.065
88.14
roll right
-0.03
-40.68
0.03
40.68
Yaw left
-0.0509
-15.27
0.0509
15.27
pitch down
-0.122
-83
0.2094
142
roll right
-0.1033
-25.8
0.1033
25.8
Yaw left
-0.0175
-14.175
0.0175
14.175
Thoracic joints:
Lumbar joints:
Table 2.13
Joints ranges of displacements.
Joints
Minimum
disp [m]
Force at min.
disp [N]
Maximum
disp [m]
Force at
max. disp [N]
x-displacement
-0.0001
-50
0.0011
50
y-displacement
-0.0009
-50
0.0009
50
z-displacement
-0.0007
-200
0.0033
400
T1-C2:
Table 2.14
Positioning joints of the facet occupant models.
Joint description
Identifier
Degree of freedom
D1 / R1
X / Roll right
D2 / R2
D3 / R3
Y / Pitch down Z / Yaw left
Sacrum-lumbar disc (L5-S1) Sacrum-L5_jnt
Roll right
Pitch down
Yaw left
Lumbar interverterbal disc
L5-L4_jnt
Roll right
Pitch down
Yaw left
,,
L4-L3_jnt
Roll right
Pitch down
Yaw left
,,
L3-L2_jnt
Roll right
Pitch down
Yaw left
,,
L2-L1_jnt
Roll right
Pitch down
Yaw left
,,
L1-T12_jnt
Roll right
Pitch down
Yaw left
Complete human
Human_jnt
37
Joint description
Release 7.6
Identifier
Degree of freedom
D1 / R1
D2 / R2
D3 / R3
Thoracic intervertebral disc
T12-T11_jnt
Roll right
Pitch down
Yaw left
,,
T11-T10_jnt
Roll right
Pitch down
Yaw left
,,
T10-T9_jnt
Roll right
Pitch down
Yaw left
,,
T9-T8_jnt
Roll right
Pitch down
Yaw left
,,
T8-T7_jnt
Roll right
Pitch down
Yaw left
,,
T7-T6_jnt
Roll right
Pitch down
Yaw left
,,
T6-T5_jnt
Roll right
Pitch down
Yaw left
,,
T5-T4_jnt
Roll right
Pitch down
Yaw left
,,
T4-T3_jnt
Roll right
Pitch down
Yaw left
,,
T3-T2_jnt
Roll right
Pitch down
Yaw left
,,
T2-T1_jnt
Roll right
Pitch down
Yaw left
Cervical intervertebral disc
T1-C7_jnt
Roll right
Pitch down
Yaw left
,,
C7-C6_jnt
Roll right
Pitch down
Yaw left
,,
C6-C5_jnt
Roll right
Pitch down
Yaw left
,,
C5-C4_jnt
Roll right
Pitch down
Yaw left
,,
C4-C3_jnt
Roll right
Pitch down
Yaw left
,,
C3-C2_jnt
Roll right
Pitch down
Yaw left
,,
C2-C1_jnt
Roll right
Pitch down
Yaw left
,,
C1-Head_jnt
Roll right
Pitch down
Yaw left
Right glenohumeral joint
ScapulaR-ArmUpR_jnt Roll right
Yaw left
Pitch down
Right elbow
ElbowR_jnt
Yaw right
Pitch down
Right wrist
WristR_jnt
Roll right
Left glenohumeral joint
ScapulaL-ArmUpL_jnt
Roll right
Yaw left
Left elbow
ElbowL_jnt
Yaw right
Pitch down
Left wrist
WristL_jnt
Roll right
Right hip
HipR_jnt
Pitch down
Roll right
Yaw left
Right knee
KneeR_jnt
Roll right
Pitch down
Yaw left
Right ankle
AnkleR_jnt
Pitch down
Roll right
Yaw left
Left hip
HipL_jnt
Pitch down
Roll right
Yaw left
Left knee
KneeL_jnt
Roll right
Pitch down
Yaw left
Left ankle
AnkleL_jnt
Pitch down
Roll right
Yaw left
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Pitch down
2.3.3
Release 7.6
Contacts
The available contact groups (in the include-file) that can be used to define contact
between the occupant and its environment in the user-file are summarised in Table
2.15.
Table 2.15
Available contact groups in the facet occupant models to define contact with
their environment.
Contact description
Identifier
Set
Complete occupant model
HumanBody_gfe
Elements
Complete occupant without arms
BodyNoArms_gfe
Elements
Complete occupant without head
BodyNoHead_gfe
Elements
Thorax
Thorax_gfe
Elements
Left arm
ArmL_gfe
Elements
Upper left arm
Upper_ArmL_gfe
Elements
Lower left arm
Lower_ArmL_gfe
Elements
Right arm
ArmR_gfe
Elements
Upper right arm
Upper_ArmR_gfe
Elements
Lower right arm
Lower_ArmR_gfe
Elements
Pelvis skin (including buttocks)
Pelvis_gfe
Elements
Left leg
LegL_gfe
Elements
Upper left leg
Upper_LegL_gfe
Elements
Left Knee
KneeL_gfe
Elements
Lower left leg (including knee)
Lower_LegL_gfe
Elements
Left shoe and foot
FootL_shoeL_gfe
Elements
Right leg
LegR_gfe
Elements
Upper right leg
Upper_LegR_gfe
Elements
Right Knee
KneeR_gfe
Elements
Lower right leg (including knee)
Lower_LegR_gfe
Elements
Right shoe and foot
FootR_shoeR_gfe
Elements
Head
Head_gfe
Elements
Neck
Neck_gfe
Elements
Left and right shoulder
Shoulders_gfe
Elements
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Release 7.6
Contact description
Identifier
Set
Back side of occupant model
HumanBody_backside_gfe
Nodes
Left part of pelvis bone
PelvisBoneLeft_gfe
Nodes
Right part of pelvis bone
PelvisBoneRight_gfe
Nodes
2.3.4
FE belt positioning and contact definition
For the contacts with the belts, for most applications it is recommended to use the
contact group HumanBody_gfe. The belt can then be fitted with the XMADgic belt
fitting tool. During the belt fitting, the initial conditions of the Scapula[LR]ArmUp[LR]_jnt and Elbow[LR]_jnt should be disabled to put the arms to the side.
2.3.5
Output
The occupant model output signals, defined in the include-file, are summarised in
Table 2.16 and Table 2.17. The occupant model injury criteria, defined in the includefile, are summarised in Table 2.18.
For the protected spine and neck joints the load output is generated by defining
bracket joints and constraint load output. The Lower and Upper neck load cells have
been defined at the T1-C7 and C1-Head (OC) joint locations, respectively. The
constraint load output of the vertebral joints Sacrum-L5 to T2-T1 are not defined in
CONTROL_OUPUT by default, but the user can add them. The constraint load
output is used to derive load cell signals in specified directions (see Table 2.17 for
neck load cells) and for the neck injury criteria FNIC and NIJ (see Table 2.18). Also,
the angular positions (ANG_POS) of the spine and neck bracket joints are defined as
output in the include file. The angular positions are not defined in
CONTROL_OUPUT by default, but the user can add them.
Table 2.16
Occupant models output.
Signal
Identifier
Degree of freedom
Filter
D1/R1
D1/R2
D1/R3
Head CG disp. w.r.t. IS6) HeadCG_lds
x
y
z
CFC1000
Head OC disp. w.r.t. IS
HeadOC_lds
x
y
z
CFC1000
T1AO disp. w.r.t. IS
T1AO_lds
x
y
z
CFC1000
Head CG disp. w.r.t.
T1AO
HeadCG_T1AO_rds
x
y
z
CFC1000
40
Signal
Release 7.6
Identifier
Degree of freedom
Filter
D1/R1
D1/R2
D1/R3
HeadOC_T1AO_rds
x
y
z
CFC1000
Sternum velocities w.r.t. Sternum_T1AO_dvl
T1AO
x
y
z
CFC600
Head OC disp. w.r.t.
T1AO
Ribs n velocities w.r.t.
spine body
Ribsn_Spine_dvl1)
y
x
z
CFC180
Head CG acc. w.r.t IS
HeadCG_lac
x
y
z
CFC1000
Head OC acc. w.r.t. IS
HeadOC_lac
x
y
z
CFC1000
T1AO acc. w.r.t. IS
T1AO_lac
x
y
z
CFC1000
Sternum acc. w.r.t. IS
Sternum_lac
x
y
z
CFC1000
Sternum_CFC180_lac
x
y
z
CFC180
Pelvis acc. w.r.t. IS
Pelvis_lac
x
y
z
CFC1000
Head CG angular acc.
HeadCG_aac
Roll right
Pitch down Yaw left
CFC1000
T1 angular acc.
T1_aac
Roll right
Pitch down Yaw left
CFC1000
1,2)
Frontal abdomen disp.
w.r.t. spine body
AbdomenFrontn
x
y
z
Frontal thorax disp.
w.r.t. spine body
ThoraxFrontn1,2)
x
y
z
Right abdomen disp.
w.r.t. spine body
AbdomenRn1,2)
x
y
z
Right thorax disp. w.r.t.
spine body
ThoraxRn1,2)
x
y
z
x
y
z
z
Left abdomen disp. w.r.t. AbdomenLn1,2)
spine body
Left thorax disp. w.r.t.
spine body
ThoraxLn1,2)
x
y
Head w.r.t. T1 cardan
output2)
Head_wrt_T13)
Roll right
Pitch down Yaw left
T1 w.r.t. inertial space
cardan output
T1_wrt_RefSpace3)
Roll right
Pitch down Yaw left
Head w.r.t. IS cardan
output
Head_RefSpace3)
Roll right
Pitch down Yaw left
Lower neck torque
NeckLow_Torque4)
Roll right
Pitch down Yaw left
CFC600
Lower neck force
NeckLow_Force4)
x
Y
CFC1000
Roll right
Pitch down Yaw left
Upper neck torque
NeckUp_Torque
4)
z
CFC600
41
Signal
Upper neck force
Upper neck force
1
Release 7.6
Identifier
Degree of freedom
NeckUp_Force4)
NeckUp_Force_CFC600
5)
Filter
D1/R1
D1/R2
D1/R3
x
y
z
CFC1000
x
y
Z
CFC600
) n = 1 to 4, number of ribs, thorax or abdomen layer, see Figure 2.4.
) This point restraint output can be found in the PTR file.
3
) Note that the cardan output is given in successive rotations. The cardan output can be found in the
CAN file.
4
) These output signals are used for calculation of the neck output specified in directions and for The
Neck Injury Criteria FNIC. The force output can be found in the RTF file and the torque output in the
RTT file. It is recommended to use the specified neck output, see Table 2.17.
5
) This output signal is used for the calculation of the Neck Injury Predictor NIJ, see Table 2.18.
6
) IS=Inertial System
2
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Table 2.17
Release 7.6
Occupant models load cell output of lower and upper neck in specified
directions.
Signal
Identifier
Degree of freedom
D1/R1
D1/R2
Filter
D1/R3
Spec. lower neck forces:
Resultant
NeckLowFRES1)
CFC1000
NeckLowFX_SHEAR
1)
Lateral shear
NeckLowFY_SHEAR
1)
Axial
NeckLowFZ_AXIAL1)
For-rearward shear
x
CFC1000
y
CFC1000
z
CFC1000
Spec. lower neck
torques:
Resultant
Lateral
NeckLowMRES1)
CFC600
1)
NeckLowMX_ROLL
For-rearward
NeckLowMY_PITCH
Axial
NeckLowMZ_YAW1)
Roll right
1)
CFC600
Pitch down
CFC600
Yaw left
CFC600
Spec. upper neck forces:
Resultant
For-rearward shear
Lateral shear
Axial
NeckUpFRES1)
CFC1000
1)
NeckUpFX_SHEAR
x
1)
NeckUpFY_SHEAR
CFC1000
y
1)
NeckUpFZ_AXIAL
CFC1000
z
CFC1000
Spec. upper neck
torques:
Resultant
Lateral
For-rearward
Axial
NeckUpMRES1)
CFC600
1)
NeckUpMX_ROLL
1)
NeckUpMY_PITCH
1)
NeckUpMZ_YAW
Roll right
CFC600
Pitch down
CFC600
Yaw left
CFC600
1
) The load cell output can be found in the INJURY file.
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Table 2.18
Release 7.6
Injury criteria of the facet occupant models.
Injury criteria
Head Injury Criterion 36 ms
Identifier
HIC_inj
Filter
2)
Contigious 3 ms criterion:
Head
Chest
Chest
Con3ms_HeadCG_inj2)
Con3ms_Sternum_CFC180_inj
Con3ms_Sternum_inj
CFC1000
2)
2)
CFC180
CFC1000
Cumulative 3 ms criterion:
Head
Chest filtered
Chest
Viscous Injury Response Criterion for
rib layer n
Cum3ms_HeadCG_inj2)
Cum3ms_Sternum_CFC180_inj
Cum3ms_Sternum_inj
VCRibsn_inj
2)
CFC1000
2)
CFC180
CFC1000
1,2)
Neck Injury Criteria:
Tension
Shear
Bending
FNICTension_inj2,3)
FNICShear_inj
2,3)
FNICBending_inj
CFC1000
CFC1000
2,3)
CFC1000 (force)
CFC600 (torque)
Neck Injury Predictor:
Tension-extension
NIJTensionExtension_inj2)
CFC600 (force)
CFC600 (torque)
Tension-flexion
NIJTensionFlexion_inj2)
CFC600 (force)
CFC600 (torque)
Compression-extension
NIJCompressionExtension_inj2)
CFC600 (force)
CFC600 (torque)
Compression-flexion
NIJCompressionFlexion_inj2)
CFC600 (force)
CFC600 (torque)
Combined Thoracic Index
CTI_inj2)
1)
n = 1 to 4, number of ribs layer, see Figure 2.4.
) The injury output can be found in the PEAK file.
3
) This injury output can also be found in the INJURY file.
2
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2.4 Examples
2.4.1
Frontal impact with a belt
An example application file of the facet occupant model with belts in a frontal impact
‘e_occ50fc_imp.xml’ can be found in $MADHOME/share/appl/3d.
2.4.2
Occupant model positioning method b
In section 2.3.2 different positioning methods have been described. Method ‘b’ is
demonstrated in an example ‘e_occ50fc_pos_b.xml’, which can be found in
$MADHOME/share/appl/3d.
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3
Release 7.6
The MADYMO facet active human model described in this chapter is currently
released in one body size. A mid-size male model representing the 50th percentile
male model population is available in a sitting and a standing position (Figure 3.1).
The sitting and the standing version of the facet active human model are identical
except for the initial joint rotations and the skin mesh of the pelvis and knees
locations.
Figure 3.1
46
Facet active human model in sitting (left) and standing (right) position.
Release 7.6
A facet mid-size male active human model is available. The input is given in the files:
Sitting mid-size male:
h_act50fc_sitting_usr.xml
h_act50fc_sitting_inc.xml
Standing mid size male:
h_act50fc_standing_usr.xml
h_act50fc_standing_inc.xml
To run this model, the following licenses are required:
Sitting mid-size male:
MADYMO/Solver (Multibody)
MADYMO/HumanActive
Standing mid-size male:
MADYMO/HumanActive
The facet active human model was based on earlier released human body models
(Meijer et al. 2012); the ellipsoid mid-size male pedestrian model, the facet mid-size
male occupant model (see Chapter 2, Happee et al. 1998), controllers to stabilise of
the spine (Cappon et al.2007), the facet detailed leg model (Cappon et al.1999), the
facet neck model (van der Horst 2002), controller to stabilise the neck model
(Nemirovsky and van Rooij 2010), a facet detailed arm model (Meijer et al. 2008),
and a shoe model. Posture controllers were implemented, wich can be activated and
deactivated.
3.1.1
Anthropometry
The anthropometry of the adult facet occupant models has been obtained from the
database of the RAMSIS software package (RAMSIS 1997). The Western European
population aged 18 to 70 years of 1984 was used. For the facet mid-size male active
human model simply medium typologies were selected for height, weight and sitting
height. In Table 3.1 the resulting anthropometry of the facet active human model is
described.
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Table 3.1
Release 7.6
Anthropometry of the facet active human model.
Parameter
Value
Standing height [m]
1.76 m
Sitting height [m]
0.92 m
Weight [kg]
75,3 kg
The mass distribution of the facet active human models is based on the RAMSIS
database. Rotational inertia were derived by integration over the segment volume,
where for each segment a homogeneous density was assumed. The neck rotational
inertia have slightly been increased to allow larger time steps for the MADYMO
calculations.
3.1.2
Configuration
The facet active human model consists of 186 bodies (178 rigid bodies and 8 flexible
bodies). The first branch connects the head and vertebral bodies to the pelvis. Two
branches connect the shoes and the bodies of the left and right leg to the pelvis.
Separate branches connect the patella, toes and some other bodies in the foot. Two
branches connect the fingers and the bodies of the arm to the spine. The thumb is
connected to the mid-hand joint on a separate branch from the fingers. The thorax and
the abdomen each consist of 4 flexible bodies that divide the thorax and abdomen in
horizontal slices. Attached to each slice at the left and right side and at the front,
bodies have been placed for attachment of force models. The thorax and abdomen
bodies are divided over 3 branches (front, left and right) for each slice.
3.1.3
Head and neck
The neck model was based on the facet neck model (van der Horst 2002). In this neck
model the surface geometries of the vertebrae and skull of this model were obtained
from a digitised 50th percentile PMHS from the European project HUMOS (Robin
2001, Hoof et al. 2001), and modified using a study of the curvature of the neck
(Jager 1996).
The head and the cervical vertebrae (C1-C7) are represented by rigid bodies. The
outer surfaces of the skull and the vertebrae consist of facets.
The intervertebral discs are modelled by point restraints and cardan restraints. The
stiffness data used for the intervertebral discs are based on literature (Moroney et al.
1988, Pintar et al. 1986a, Eberlein et al. 1999, Camacho et al. 1997).
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Release 7.6
The articular facet joints and contacts between the spinous processes are modelled by
a point-restraint with resistance in the compression direction only. The contacts
between skull (OC) and C1 and between C1 and C2 (dens) are modelled by an FE-FE
contact with a stress-penetration characteristic. The OC of C1-skull and the dens
contact area of C1-C2 have a detailed mesh in order to have a convex-concave
smooth contact area. Ligaments surrounding the dens and the joint capsules offer
resistance in tension and shear and are modelled with kelvin restraints.
The nuchal ligaments are each modelled by a Kelvin restraint. The elastic properties
are initially based on experimental studies (Pintar 1986b, Yoganandan et al. 2001).
Only the stiffness of the upper neck ligaments were increased compared to the
experimental data in order to avoid unrealistic large motions of the upper neck in
flexion and extension.
The facet neck model includes 68 pairs (left/right) of muscle elements. These are used
for passive resistance and for the hip controller, described in more detail in 3.1.11.
The positions of attachments are based on detailed anatomy text books (Kapandji
1974, Platzer 1989, Quiring 1947), data on bony geometry (Panjabi et al. 1991a,
Panjabi et al. 1991b) and choices made by other researchers in this field (Deng and
Goldsmith 1987, Seireg and Arvikar 1989, Winters & Peles 1990). Each muscle
element is divided into segments which are supported on the applicable vertebrae by
intermediate sliding points enabling muscles to curve around the vertebrae. These
sliding points are located on the points of intersection of the muscle line of action in
initial position and the xy-plane of the intermediate vertebrae. Figure 3.2 shows all
the muscles and ligaments in the facet neck model.
Figure 3.2
The head/neck model, including bones and muscles, excluding skin.
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3.1.4
Release 7.6
Spine
The lumbar and thoracic spine were modelled in such a way that it gives a biofidelic
response in a wide range of loading conditions. The vertebrae were modelled by rigid
bodies connected by free joints and lumped restraint models in 3 rotational and 3
longitudinal directions (RESTRAINT.SIX_DOF). These joint resistance models
describe the dynamic response of the intervertebral discs, ligaments and effects of
muscular resistance in a global way. The geometries of the lumbar and thoracic
vertebrae are each described by a single ellipsoid. The neutral position of the spine
represents the spinal curvature of an erect standing person.
3.1.5
Thorax and abdomen
In an impact loading case the human thorax and abdomen can deform in a complex
3D manner due to contact but also due to spinal deformations. This has been
modelled by using flexible bodies (see MADYMO Theory Manual and Koppens
1988). The flexible bodies describe 3D deformations with only a few degrees of
freedom and are therefore efficient. The flexible bodies describe global deformations
while the contact algorithm describes local deformation. The resulting capability to
model torso deformation was found to correspond with experimental data.
The thorax and the abdomen each consist of 4 flexible bodies. The flexible bodies
divide the thorax and abdomen in horizontal slices, as is shown in Figure 3.3. The
geometry of the flexible bodies is determined by the position of the skin nodes of the
flexible body in concern. A point mass has been assigned to each node.
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Release 7.6




Figure 3.3
Right view of the facet active human model with the arrows pointing to the
flexible bodies, and the rigid bodies shown as green dots.
The flexible bodies are each connected to the closest rigid vertebral body of the spine.
Each flexible body is able to deform in 3 predefined deformation modes: 1 frontal
mode and 2 lateral modes (left and right). The modes were determined analytically as
linear functions of the co-ordinates of the nodes. The frontal mode contains both xand y-displacements, the lateral modes only contain y-displacements. The input
options for the flexible bodies only allow linear stiffness and damping, which is not
sufficient for describing the demonstrated non-linear behaviour of the torso in impact.
Therefore, point restraints were added for modelling the frontal and lateral stiffness
and damping of the flexible bodies, and the stiffness and damping in all modes were
set to negligible low values (setting these values to zero is not allowed in
MADYMO).
For attachment of the point restraints rigid bodies were added: 1 frontal, 1 left and 1
right of each flexible body. These rigid bodies are connected to the skin nodes of the
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Release 7.6
flexible body. The point restraints at the frontal bodies and the lateral bodies only
contribute to loading in the x-direction and y-direction, respectively. Coupling
between frontal and lateral deformation is taken into account by the frontal
deformation mode.
Vertical point restrains were added between the rigid bodies of each flexible body.
These point restraints do not only have a z-component, but also have a small x- or ycomponent for frontal respectively lateral stiffness. This was done in order to obtain a
more realistic skin deformation.
The two lowest flexible bodies also model the iliac wings. Since no biomechanic data
was available the resistance for frontal loading of these two lowest flexible bodies is
based on a model of the Hybrid III 50th percentile dummy.
3.1.6
Shoulders and arms
The shoulder and arms are based on a shoulder-arm model developed in the EU
project APROSYS (Meijer et al. 2008). The skeleton of the shoulders and arms are
modelled with rigid bodies for each bone (clavicle, scapula, humerus, ulna, radius).
The clavicles are each connected to the sternum with a free joint, which besides the
rotations allows for some translations to represent clavicle and sternum deformation.
The acromio-clavicular (clavicle-scapula) and gleno-humeral (scapula-humerus)
joints are spherical joints, allowing three rotations. The elbow and radio-ulnar (lower
arm rotation) joints are both modelled with revolute joints with only one degree of
freedom. The wrist is modelled with a universal joint with two degrees of freedom.
The hand is modelled by a 3-segment thumb and a 3-segment combined fingers. The
joints of thumbs and fingers are locked, making the hands rigid. In all joints in the
arms (except the hands) restraints are applied to model the range of motion and the
resistance.
In the human body, the scapulae contact the thorax. Active muscle force is needed to
maintain this contact and to stabilise the shoulder girdle. These complex interactions
between shoulder and thorax have been modelled by a set of passive restraint models.
The scapula is supported on the spine by point restraints to T1 and T7. Thus, the load
transfer from shoulder to spine has been modelled by the skeletal connection
(scapula-clavicle-sternum-ribs-spine) and by these additional restraint models.
The main muscles in the arm are also included in the model. These are used for
passive resistance and for the elbow controller, described in more detail in 3.1.11. The
geometry of the scapula, clavicle, humerus, ulna and radius is represented by a facet
surface. The arm model is shown in Figure 3.4.
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Figure 3.4
3.1.7
Release 7.6
The (left) shoulder/arm model, including bones and muscles. Arm skin shown in
wireframe.
Legs
The hip joints, connecting the legs to the pelvis, were modelled by spherical joints
with cardan restraints. The knee joints, connecting the upper leg to the lower leg,
were modelled by free joints with point restraints and cardan restraints. In this way
the knee has all degrees of freedom and allows predicting knee shear which is
common in car-pedestrian impact. The ankles, connecting the feet to the lower legs,
have been modelled by spherical joints with cardan restraints. The feet have been
modelled in much detail, all the feet bones and the joints between these bones are
included. However, the joints in the feet are locked, since they do not affect the
kinematics of the human in most scenarios when there are shoes around the feet.
In pedestrian impacts, bending and fracture of the leg bones can affect the kinematics
of the pedestrian. To account for this in both the femur and tibia/fibula spherical
joints were implemented in order to model bending and fracture. Cardan restraints
were implemented at all the bending joints to model the bending stiffness of femur
and tibia/fibula. The bending stiffness is assumed to be equal throughout one long
bone. Therefore, the same characteristics have been used for all three cardan restraints
within one bone.
In car-pedestrian collisions fracture most often occurs in the lower leg. Therefore,
only one fracture joint was implemented at the middle of the femur and three fracture
joints at the tibia/fibula leg joints. All fracture joints are spherical joints that are
initially locked until a pre-defined fracture trigger signal exceeds the fracture
tolerance level. The implemented fracture levels for the upper and lower leg are based
on 50% injury risk, see Table 3.3. These levels can be adapted in the model for
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studying a specific population, like for instance elderly people, provided that these
tolerance levels are know for this specific population group. This can be done by
changing the values for the DEFINE elements in the user file
([Femur|Tibia]Fract[Force|Torque]Lat).
Once the fracture tolerance is exceeded, the angular resistance in the fracture joint is
set to zero and both parts of the fractured bone are free to rotate relative to each other.
Minor rotational damping was implemented in the fracture joints to avoid numerical
instabilities once fracture occurred.
Table 3.3
Fracture levels for the upper and lower leg, based on 50% injury risk.
Model part
Torque [Nm]
Reference
Shear force
[N]
Reference
Upper leg
430
EEVC WG17
6000
Based on EEVC
WG17
Lower leg
285
Nyquist et al. (1985)
4000
Yang et al. (2000)
Mid-size male:
In total 43 muscle elements have been modelled in the leg. These are used for passive
resistance and for the hip controller, described in more detail in 3.1.11. The set of
muscles used in the model has been derived from Delp (1990). Eleven ligaments have
been implemented in the ankle joint and foot. The ligaments in the ankle are needed
to stabilise the ankle joint and were adopted from Parenteau (1996). The geometry of
the pelvis, femur, tibia, patella and fibula was adopted from Delp et al. (1990) and
scaled to fit the existing outer geometry. It is represented by a facet surface, . As no
fibula bodies are included, the fibula mesh is attached to the tibia. The leg model is
shown in Figure 3.5.
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Figure 3.5
3.1.8
Release 7.6
The (left) leg/foot model, including bones and muscles. Leg skin shown in
wireframe.
Shoes
The shoes each consist of a rigid body with a facet surface supported to it. The shoes
are each connected to a foot by a free joint. The feet nicely fit in the shoes and contact
between foot and shoe is defined, allowing some movement of the feet with respect to
the shoes like in reality. Figure 3.6 shows the right shoe.
Figure 3.6
3.1.9
Right shoe of the facet active human model.
Skin and bones
The outer surface of the facet occupant model (skin) is described by a mesh of
triangular elements defined as a null material. The skin is divided into several
sections that are supported on the nearest bodies. In the thorax and abdomen area the
skin is supported by flexible bodies. Different parts of the skin have different contact
55
Release 7.6
characteristics, based on validation. For the legs, pelvis, arms and neck also the bones
are included. Similar to the skin, these are described by a mesh of elements defined as
a null material. The skin and bones are both used in the contact groups.
3.1.10 Contacts
The contacts between different parts of the human body are already defined in the
model. These contacts can be found in Table 3.4.
Table 3.4
Inter body part contacts for the facet active human model.
Contact
Master Surface
Slave Surface
Body_Head
BodyNoHead_gfe
Head_gfe
Body_ArmL
BodyNoArms_gfe
ArmR_gfe
ArmL_gfe
Body_ArmR
BodyNoArms_gfe
ArmL_gfe
ArmR_gfe
LegR_LegL
LegR_gfe
LegL_gfe
LegR_to_ShoeL
LegR_gfe
ShoeL_gfe
LegL_to_ShoeR
LegL_gfe
ShoeR_gfe
ShoeL_to_ShoeR
ShoeR_gfe
ShoeL_gfe
ShoeL_to_LegR
ShoeL_gfe
LegR_gfe
ShoeR_to_LegL
ShoeR_gfe
LegL_gfe
ShoeR_to_ShoeL
ShoeL_gfe
ShoeR_gfe
FootL_to_ShoeL
FootL_gfe
ShoeL_FootCont_gfe
FootR_to_ShoeR
FootR_gfe
ShoeR_FootCont_gfe
ShoeL_to_FootL
ShoeL_FootCont_gfe
FootL_gfe
ShoeR_to_FootR
ShoeR_FootCont_gfe
FootR_gfe
SkullOC_C1_cnt
Skull_gfe
C1_gfe
C2dens_C1_cnt
C1_gfe
C2dens_gfe
3.1.11 Active behaviour control
The active human model contains controllers for the neck, spine, elbows and hips.
These controllers will by default try to maintain the initial position under the
influences of external loading. However, by means of a target angle function per
degree of freedom, also some controlled movements (voluntary or reflex) can be
56
Release 7.6
simulated. For the neck, also co-contraction is included for simulating the stiffening
effect of bracing.
All controllers in the active human model are based on the scheme shown in Figure
3.7. First this basic scheme will be explained, followed by for each body part an
explanation of some more details and possible deviations from the basic setup.
User input
Sensor
Target
signal
per DOF
Reaction
time
Activation
switch
per body
part
Error
Reaction
time
delay
Activation
switch
Initial
activation
per DOF
PID
controller
Neural delay
Addition of
initial
activation
Muscle
recruitment
Actuator /
Muscles
Activation
level
output
Sensor
output
Figure 3.7
Basic controller scheme, with user input (top), main controller flow (mid) and
available output (bottom).
The basic controller scheme starts with the sensors. For each degree of freedom that is
controlled, a sensor is defined to measure the motion. Also, a target signal is defined
which can be changed by the user (to simulate e.g. voluntary movement), but which
by default is 0 in order to stabilise toward the initial position. The control error is then
calculated as the difference between the sensor and target signals.
The next step is the reaction time. Here, the reaction time represents the time it takes
for the human brain to start responding to any new event. This includes the time
needed for the sensing, transfer of the signal to the brain and processing in the brain.
This cannot be included in the model as a pure time delay, as this would cause the
controller to respond to events which occurred in the past. For example, in a crash
scenario with a duration of 100 ms, and a reaction time of 200 ms, 100 ms after the
crash the controllers would make the model starting to move based on control errors
found during the crash, which is considered unrealistic. This would also make the
model unstable. Therefore, the reaction time is implemented such that:


Control errors related to pure stabilising behaviour, without any new events,
causes a direct response
New events only cause a response with a delay of the reaction time.
57
Release 7.6
A new event is defined as any external load causing a control error that is larger than
the maximum error occurred in the simulation up to the current time step. New events
are automatically detected by the active human model. If the error remains below the
maximum, the signal is transferred directly, but if the error is above the maximum, it
is limited to the maximum during the reaction time before it increases further. An
example with arbitrary input is shown in Figure 3.8.
Figure 3.8
Example of the effect of the reaction times on the signal output of the
controllers. The output signal is limited by the delayed (reaction time)
maximum of the input.
For each body part (neck, spine, elbow, hip) the active behaviour can be switched on
or off. This is done by multiplying the control signal with the activation parameter,
where ‘0’ results in no active behaviour, and ‘1’ results in active behaviour (posture
maintenance).
The PID controller aims to reduce the error by calculating a correcting load. The Paction changes the controller action based on the present error. The I-action makes
sure the controller will reduce the error to zero by integrating the past errors. To damp
out oscillations and reduce future errors the D-action makes the controller action
larger if the error is increasing and smaller if the error is decreasing.
After the PID-controller, a neural delay is implemented. The neural delay represents
the time it takes for the signal transfer from the brain to the muscle and the time it
takes for the muscle to convert the signal into a force. This neural delay is defined as:
d (output ) / dt  (input  output ) /  delay _ time
58
Release 7.6
For the controllers on the neck muscles  delay_ time is set to 40 ms, for the spine
controllers to 70 ms, for controllers on the muscles in the arms to 70 ms and for the
controllers on the muscles in the legs to 100 ms. The neural delay behaves frequency
dependent, so signals with lower frequencies are transferred better than signals with
higher frequencies, and the delay decreases with increasing frequencies. This is
shown in Figure 3.9, where for a step function and for a swept sine as input, the
output of the neural delay is shown.
Figure 3.9
Frequency dependent behaviour of the neural delay for a step function (left) and
swept sine(right).
In order to be able to have a simulation that has initial equilibrium, some kind of
initialisation of the controllers is required. To achieve this, a user defined initial
activation level has been implemented, which is added to the controller signal. The
required values for the initialisation can be taken from the output of a settling
simulation in which the model is run with only gravity applied to find an equilibrium.
Finally, the signal from the controller, being one signal per degree of freedom, is
converted to a signal for each actuator. This is done by means of a recruitment table
with for each degree of freedom and for each actuator a constant factor, to obtain a
weighted combination of the different degrees of freedom. The converted signals are
then used as input for the actuators, which can either be muscles or multi-body
actuators.
The neck controller acts in three degrees of freedom, being the three rotations of the
head. For each degree of freedom the neck controller follows the basic scheme as
explained above. Depending on the user settings, the head rotations are either
calculated relative to the reference space, to keep the head upright, or relative to T1,
to keep the neck straight. As the vestibular system is in the head, usually a human will
59
Release 7.6
aim to keep its head upright. However, for large rotations of the body, like e.g. in a
pedestrian impact, a strategy which keeps the neck straight is considered more
realistic. Hence the user can select whether the head angles are calculated relative to
the reference space or relative to T1. The muscle recruitment table for the neck is
taken from the model of Nemirovski (2010). Here, the recruitment table is balanced,
which means that an error in one degree of freedom results in a torque in only that
degree of freedom. Besides the control on the three degrees of freedom of the head,
also neck co-contraction is implemented, which is the simultaneous tension of all
muscles without giving any resultant torques. Co-contraction will always be present
to some extent, and is possibly higher if a person is tensed. In the active human model
the co-contraction level is defined by the initial input as a relative value (0-1) of the
maximum possible muscle activation. After application of the reaction time and the
neural delay, the co-contraction level is included in the calculation of the muscle
recruitment. The co-contraction is balanced for any pitch angle. As usually a constant
co-contraction ratio is used, the delays can be switched off with the user settings, to
avoid the co-contraction to have to build up from zero during the first part of the
simulation.
The controllers on the left and right hip each act in three degrees of freedom, being
the three rotations of the hip joint, flexion-extension, medial-lateral rotation, and
abduction-adduction. For each degree of freedom the hip controller follows the basic
scheme as explained above. The muscle recruitment table for the hip is set up such,
that for a specific degree of freedom the muscles that have most effect in that degree
of freedom are activated the most.
The controllers on the left and right arm each act in only one degree of freedom per
side, being the elbow flexion-extension. For flexion-extension the elbow controller
follows the basic controller scheme as explained above. The muscle recruitment for
the elbow divides the muscles in a group of flexors and a group of extensors and
activates all muscles in one group to the same extent.
The spine controller acts in three degrees of freedom per vertebra for each of the 5
lumbar and 12 thoracic vertebrae, so 17 vertebrae in total. For each vertebra, sensors
are defined to measure the angle of the vertebra relative to the sacrum (pelvis). For
the spine no target functions are defined. Hence, the rotation error for the spine is
equal to the sensor output. Regarding the reaction time, activation switch, PIDcontroller and neural delay, the spine controller follows the basic scheme as explained
above. The activation signal for each vertebra is then applied to that vertebra as well
as to the vertebrae below, such that the spine is in a stable position. Finally, the initial
activation levels are added to the activation signal (as in the basic scheme) and the
signal is used in the actuators. For the spine, no muscles are included because of the
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Release 7.6
complexity of the musculature of the thorax. Instead, multi-body actuators are used to
directly apply a torque between two successive vertebrae.
The facet mid-size male active human model has been validated extensively for
various loading conditions. Two major categories of tests were conducted: volunteer
tests for low severity loading and post mortem human substitute (PMHS) tests for
higher severity loading. The blunt impact and segment tests are listed in 3.2.1, the
sled and vehicle tests in 3.2.2 and the vibration tests in 3.2.3.
3.2.1
Blunt impact and segment tests
Blunt impact and segment tests used for the validation of the facet active human
model are summarised in Table 3.5.
Table 3.5
Blunt impact and segment tests used for validation of the facet active human
model.
Test
Reference
Segment
Description
Test object
Specifications
Head
2 frontal impact
PMHS
2.0, 5.5 m/s
Melvin (1985), Don et al.
(2003)
Shoulder
2 lateral impact
PMHS
4.5, 5.5 m/s
ISO TR9790 (1997), Meyer
et al. (1994), Lizee et al.
(1998)
Thorax
9 frontal impact
PMHS
3.4–9.9 m/s
Bouquet et al. (1994),
Neathery (1974), Kroell et
al. (1971, 1974, 1976),
Nahum et al. (1970,1975)
2 lateral impact
PMHS
3.3, 5.9 m/s
Bouquet et al. (1994), Lizee
et al. (1998)
1 frontal impact
Volunteer
1.83 m/s
Muggenthaler et al. (2005),
Cappon (2007)
3 frontal impact
PMHS
6.9-9.4 m/s
Cavanaugh (1986), GESAC
(2001), Nusholtz & Kaiker
(1995)
2 rigid drop tests on
armrest
PMHS
4.4, 6.3 m/s
ISO TR9790 (1997)
3 oblique impact
PMHS
4.8-9.4 m/s
Viano (1989)
Abdomen
61
Release 7.6
Pelvis
4 lateral impact
PMHS
3.6-9.8 m/s
Bouquet et al. (1994), Viano
(1989)
Leg
4 lateral impact
PMHS
15, 20 m/s
Kajzer (1990), Kajzer (1993)
3.2.2
Sled and vehicle tests
Sled and vehicle tests used for the validation of the full body behaviour of the facet
active human model are summarised in Table 3.6.
Table 3.6
Sled and vehicle tests used for validation of the facet active human model.
Test
Reference
Direction
Description
Test
object
specifications
Frontal
Rigid seat on sled
Volunteers
15 g peak
Thunnissen et al. (1995)
Rear
Rigid seat on sled
Volunteers
3.6 g peak
Ono et al. (1999)
Rear
Rigid seat on sled
PMHS
9-12 g peak
Bertholon et al. (2000)
Lateral
Rigid seat on sled
Volunteer
7.0 g peak
Ewing et al. (1972)
Lateral
Rigid seat on sled
PMHS
6.3, 8.7 m/s
Irwin et al. (1993)
Vertical
Rigid seat on sled
Volunteers
6, 10 g
Miller et al. (1989)
Rollover
Car seat on sled
Volunteers
rotation
Cappon et al. (2007)
Lateral
Car seat on sled
Volunteers
-2.5 – 4 g
Meijer et al. (2003)
Lateral
Pedestrian impact
PMHS
25-39 km/h
Ishikawa et al. (1993)
Frontal
Lateral
Car seat in car
Volunteers
Volunteers
Braking (<1g)
Braking (0.5g)
Schoeneburg (2011)
Van Rooij et al.(2013)
3.2.3
Remote-controlled
test vehicle
Vibration tests
Vibration tests used for the validation of the full body behaviour of the facet active
human model are summarised in Table 3.7.
62
Table 3.7
Release 7.6
Vibration tests used for validation of facet active human model.
Test
Reference
Direction
Description
Test object
Specifications
Vertical
Rigid seat
Volunteers
0.5-15 Hz, 0.4 G peak
Frontal
Rigid seat
Volunteers
0.35-4.05 Hz, 0.5 g peak
Keshner(2003)
3.3.1
Table 3.8
Recommended integration method and time step for the facet active human
models.
Model
Integration method
Time step (s)
Sitting mid-size male
EULER
<1.0E-05
Standing mid-size male
EULER
<1.0E-05
3.3.2
Positioning
In order to position the human model, the INITIAL.JOINT_POS elements have to be
used. All joints that are needed for positioning the human model are defined in the
INITIAL.JOINT_POS elements in the human model user-file. Positions of all other
joints are defined in the human model include-file, and these should not be edited by
the user.
A human model is by default positioned relative to the (global) reference space
coordinate system. However, the human model can be positioned relative to a body of
another system. This can be done in the CRDSYS_OBJECT ‘Human_Attachment’
and the associated ORIENTATION ‘Human_Attachment_ori’. The human
attachment element ‘Human_Attachment’ is comparable to the dummy attachment
element 'Dummy_attachment' in a dummy model, which is located at the H-point.
The orientations of the positioning joints are given in Table 3.9. In this table all
rotations are referred to with the terms pitch, roll and yaw, as well the anatomical
terms for the arms and legs. The directions given in the tables refer to positive
rotation directions. For all joints, the directions are defined with respect to their
coordinate system orientation, when the human model is in its reference position, as
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Release 7.6
shown in Figure 3.10, in which all initial rotations are equal to zero. The anatomical
terms for the rotations of the arms and legs are also in the DESCRIPTION attributes
in INITIAL.JOINT_POS in the user file.
The sitting and standing model have different predefined initial conditions (as shown
in Figure 3.1), to be closer to the initial conditions in a common application. The
standing model is in an erect standing position with S-curvature in the spine, while
the sitting model is in a relaxed seating position with C-curvature in the spine. The
initial vertebral joint rotations of the sitting facet active human model are according to
Davidsson et al. (1998), the values are given in Table 3.10.
Figure 3.10
Definition of joint translations and rotations of the facet active human model in
its reference position.
Table 3.9
Positioning joints of the facet active human model.
Joint description Identifier
Complete human
64
Human_jnt
Degree of freedom
D1 / R1
D2 / R2
D3 / R3
X / Roll right
Y / Pitch down
Z / Yaw left
Release 7.6
Degree of freedom
D1 / R1
1)
D2 / R2
1)
D3 / R3
Lumbar intervertebral L5_jnt
joint
X / Roll right
1)
Y / Pitch down
Z1) / Yaw left1)
,,
L4_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
L3_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
L2_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
L1_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Thoracic
intervertebral joint
T12_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T11_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T10_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T9_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T8_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T7_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T6_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T5_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T4_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T3_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T2_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T1_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Cervical intervertebral C7_jnt
joint
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C6_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C5_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C4_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C3_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C2_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Atlanto-axial joint
C1_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Atlanto-occipital joint HeadOC_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Sternum joint1)
SternumUp_jnt1)
X1) / Roll right1)
Y1) / Pitch down1) Z1) / Yaw left1)
Left sterno-clavicular
joint1)
SternoClavicularL
_jnt1)
-X1) / Roll left1)
Y1) / Pitch down1) -Z1) / Yaw right1)
Right sternoclavicular joint1)
SternoClavicularR
_jnt1)
X1) / Roll right1)
65
Release 7.6
Degree of freedom
D1 / R1
1)
D2 / R2
Yaw right1)
Left acromioclavicular joint1)
AcromioClavicularL
_jnt1)
Roll left
Right acromioclavicular joint1)
AcromioClavicularR
_jnt1)
Roll right1)
Pitch down1)
Yaw left1)
Left glenohumeral
joint (shoulder)
GlenohumeralL_jnt
Adduction
(roll left)
Flexion
(yaw right)
Lateral rotation
(pitch up)
Right glenohumeral
joint (shoulder)
GlenohumeralR_jnt
Adduction
(roll right)
Flexion
(yaw left)
Lateral rotation
(pitch up)
Left elbow
ElbowL_jnt
Flexion
(yaw right)
Right elbow
ElbowR_jnt
Flexion
(yaw left)
Left radio-ulnar joint
RadioUlnarisL_jnt
Supination
(pitch down)
Right radio-ulnar joint RadioUlnarisR_jnt
Supination
(pitch down)
Left wrist
WristL_jnt
Flexion
(roll left)
Adduction
(yaw right)
Right wrist
WristR_jnt
Flexion
(roll right)
Adduction
(yaw left)
Left fingers2)
FingerUp/Mid/LowL Flexion
_jnt
(roll left)
Right fingers2)
FingerUp/Mid/LowR Flexion
_jnt
(roll right)
Left thumb2)
ThumbUp/Mid/LowL Flexion
_jnt
(roll left)
Right thumb2)
ThumbUp/Mid/Low
R_jnt
Flexion
(roll right)
Left hip
HipL_jnt
Extension
(pitch down)
Adduction
(roll left)
Lateral rotation
(yaw left)
Right hip
HipR_jnt
Extension
(pitch down)
Adduction
(roll right)
Lateral rotation
(yaw right)
Left knee
KneeL_jnt
Adduction1)
(roll left)
Flexion
(pitch down)
Medial rotation1)
(yaw right)
Right knee
KneeR_jnt
Adduction1)
(roll right)
Flexion
(pitch down)
Medial rotation1)
(yaw left)
66
Pitch down
D3 / R3
1)
Release 7.6
Degree of freedom
D1 / R1
D2 / R2
D3 / R3
Left ankle
AnkleL_jnt
Lateral rotation
(yaw left)
Plantarflexion
(pitch down)
Inversion
(roll left)
Right ankle
AnkleR_jnt
Lateral rotation
(yaw right)
Plantarflexion
(pitch down)
Inversion
(roll right)
Left shoe joint1)
ShoeL_jnt1)
X1) / Roll right1)
Right shoe joint1)
ShoeR_jnt1)
X1) / Roll right1)
1
) Not to be changed during manual positioning. Only for equilibrium, based on a settling simulation.
) Included in a DISABLE block in the user file
2
67
Table 3.10:
Release 7.6
Vertebral joint rotations in a relaxed seating position according to Davidsson et.
al. (1998).
Joint orientation
identifier
Degree of freedom
Sacrum-L5_ori
R1
0
R2
0.1021
R3
0
L5-L4_ori
0
0.0821
0
L4-L3_ori
0
0.0348
0
L3-L2_ori
0
0.0348
0
L2-L1_ori
0
0.0348
0
L1-T12_ori
0
0.0346
0
T12-T11_ori
0
0.0346
0
T11-T10_ori
0
0.0346
0
T10-T9_ori
0
0.0346
0
T9-T8_ori
0
0.0346
0
T8-T7_ori
0
0.0346
0
T7-T6_ori
0
0.0346
0
T6-T5_ori
0
0.0346
0
T5-T4_ori
0
0.0146
0
T4-T3_ori
0
0.0146
0
T3-T2_ori
0
0.0146
0
T2-T1_ori
0
0.0146
0
T1-C7_ori
0
0
0
C7-C6_ori
0
0
0
C6-C5_ori
0
0
0
C5-C4_ori
0
0
0
C4-C3_ori
0
0
0
C3-C2_ori
0
0
0
C2-C1_ori
0
0
0
C1-Head_ori
0
0
0
68
Release 7.6
Positioning of the facet active human model, using a pre-simulation to obtain an
equilibrium, is done in three steps:
1. The facet active human model is positioned manually as described above, using
the Human_attachment and INITIAL.JOINT_POS elements in the user file. The
human model can best be positioned just above the seat with its pelvis at the
correct horizontal position.
2. A pre-simulation is performed in which the facet active human model is put into
the seat using a gravitational field only (acceleration field of -9.81 m/s2 in zdirection). The run time for positioning the facet active human model needs to be
sufficiently large for the model to find its equilibrium (typically about 0.5 to 1 s).
All active behaviour should be switched on (DEFINE’s set to 1) in order to
maintain an upright seating position. The joint position degrees of freedom
(JOINT_DOF) of all joints in the user-file should be defined in the output
(OUTPUT.JOINT_DOF). The joints of which the initial positions are not defined
in the user-file should be locked. Also the state of the flexible bodies in the thorax
and the abdomen should be set to rigid. To facilitate these steps, in the user file a
DISABLE element is included which contains all xml-elements required to define
the output and to lock the non-positioning joints and flexible bodies. Depending
on the application, some additional joints could be locked, like e.g. the wrists and
radio-ulnar joints to keep the arms in the desired position, or some point-restraints
can be added to keep e.g. the hands on a steering wheel.
3. The output from the last time step in the JNTPOS file of the pre-simulation
should be copied to the positioning elements (INITIAL.JOINT_POS) of the
impact simulation file. For this the Import-INITIAL.JOINT_POS tool in
XMADgic can be used. In the impact simulation, the joints and bodies that were
locked/rigid for the settling should be set to free/deformable again, and possible
added point-restraints should be removed and the belt can be fitted around the
positioned human model using e.g. the XMADgic belt fitting tool. To have the
controllers start at the levels reached during the settling, the activation levels in
the last timestep of the *.control file of the settling should be used to define the
initial activation levels in the model, as described in paragraph 3.3.6.
69
3.3.3
Release 7.6
Contacts
Table 3.11
Available contact groups in the facet active human model to define contact with
its environment.
Contact description
Identifier
Set
Complete human model
HumanBody_gfe
Elements and nodes
Complete human without arms
BodyNoArms_gfe
Elements and nodes
Complete human without head
BodyNoHead_gfe
Elements and nodes
Head
Head_gfe
Elements and nodes
Neck
Neck_gfe
Elements and nodes
Thorax
Thorax_gfe
Elements and nodes
Pelvis_gfe
Elements and nodes
IliacWings_gfe
Elements and nodes
ArmL_gfe
Elements and nodes
ArmR_gfe
Elements and nodes
ShoulderBonesLeft_gfe
Elements and nodes
ShoulderBonesRight_gfe
Elements and nodes
Upper left arm
Upper_ArmL_gfe
Elements and nodes
Upper right arm
Upper_ArmR_gfe
Elements and nodes
Lower left arm (incl. hand)
Lower_ArmL_gfe
Elements and nodes
Lower right arm (incl. hand)
Lower_ArmR_gfe
Elements and nodes
Complete left leg
LegL_gfe
Elements and nodes
Complete right leg
LegR_gfe
Elements and nodes
Upper left leg
Upper_LegL_gfe
Elements and nodes
Upper right leg
Upper_LegR_gfe
Elements and nodes
Lower left leg (excl. foot/shoe)
Lower_LegL_gfe
Elements and nodes
Lower right leg (excl. foot/shoe)
Lower_LegR_gfe
Elements and nodes
Left shoe
ShoeL_gfe
Elements and nodes
Right shoe
ShoeR_gfe
Elements and nodes
Pelvis
Iliac wings
1)
Complete left arm
Complete right arm
Bones of left shoulder and upper arm
2)
Bones of right shoulder and upper arm
1
2)
) To be used in the lapbelt contact predefined in the user file.
) To be used in the shoulderbelt contact predefined in the user file.
2
70
3.3.4
Release 7.6
FE belt positioning and contact definition
For the contacts with the belts, in the sitting model contacts have been predefined in a
DISABLE block. If a belt is added to the model, these contacts should be enabled and
the references to the belt groups (SLAVE_SURFACE) should be updated.
Characteristic based contacts are predefined between the belts and BodyNoArms_gfe.
These are the main contact between the human and the belt. In order to prevent
unrealistic deep penetrations of the belt in the human body, surface-to-surface
contacts with edge-contact have been predefined between the belts and the relevant
bones.
The advantage of using the group BodyNoArms_gfe, is that once the contacts with
the belt are defined, the XMADgic belt fitting tool will automatically detect this
group for the belt fitting and the belt can be fitted without interference of the arms. In
most applications the belts will not contact the arms, so that omitting these from the
contact is no problem. Depending on the position of the human model ans the belt
anchor points, the XMADgic beltfitting tool might incorrectly fit the shoulderbelt
underneath the legs. This then can be resolved by selecting Thorax_gfe in the belt
fitting tool.
If the arms need to be included in the belt contact, it is recommended to use the
contact group HumanBody_gfe. In that case during belt fitting either the user should
select the group BodyNoArms_gfe, or the initial conditions of the
Glenohumeral[LR]_jnt and Elbow[LR]_jnt should be disabled during the belt fitting
to put the arms to the side. Disabling these initial conditions during belt fitting is also
required when using XMADgic version 7.4 or before.
It is important to bear in mind that many injury criteria available in the model have
been developed for the assessment of injury risk based on the performance of the
ATDs, and and the injury risk may not directly correlate when calculated using the
active human model output. Similarly, the chest deflection signal ChestDeflection_dis
is an approximation to the corresponding hybrid-III output.
3.3.5
Output
The facet active human model output signals, defined in the include-file, are
summarised
in
71
Release 7.6
Table 3.12, Table 3.13 and Table 3.14. The facet active human model injury criteria,
defined in the include-file, are summarised in Table 3.15.
72
Table 3.12
Release 7.6
Facet active human model time history output.
Signal
Identifier
Degree of freedom
HeadCG_aac
Roll right Pitch down Yaw left CFC1000
T1 angular acc.
T1_aac
Head w.r.t. IS angular
displacement
Head_ang
T1 w.r.t. IS1) angular
displacement
T1_ang
Head w.r.t. T1 angular position
Head_T1_ang
D1/R1
D1/R2
Filter
D1/R3
10)
Left/Right knee bending/torsion KneeS_ang
Flexion
Lateral
bending
Torsion
CFC1000
Head CG acc. w.r.t IS2)
HeadCG_acc
x
y
z
CFC1000
HeadOC_ acc
x
y
z
CFC1000
C1_acc_CFC60
x
y
z
CFC60
T1_acc
x
y
z
CFC1000
T1_acc_CFC60
x
y
z
CFC60
T12_acc
x
y
z
CFC1000
Sternum_acc
x
y
z
CFC1000
x
y
z
CFC180
x
y
z
CFC180
2)
C1 acc. w.r.t. IS2)
T1 acc. w.r.t. IS
2)
T12 acc. w.r.t. IS
2)
Sternum acc. w.r.t. IS
2)
Sternum_acc_CFC180
4)
Chest acc at central ribcage n
w.r.t. IS2)
ThoraxnFront_acc_CFC180
Chest acc at left rib n w.r.t. IS2)
ThoraxnL_acc_CFC1804)
x
y
z
CFC180
4)
x
y
z
CFC180
x
y
z
CFC1000
x
y
z
CFC1000
Chest acc at right rib n w.r.t.
IS2)
ThoraxnR_acc_CFC180
Left/Right femur acc. w.r.t. IS2)
FemurnS_acc 3,10)
Left/Right tibia acc. w.r.t. IS
2)
TibianS_acc
3,10)
Head CG disp. w.r.t. IS
HeadCG_dis
x
y
z
CFC180
HeadOC_dis
x
y
z
CFC1000
T1 disp. w.r.t. IS
T1_dis
x
y
z
CFC1000
Head CG position w.r.t. IS
HeadCG_pos
x
y
z
CFC180
T1 position w.r.t. IS
T1_pos
x
y
z
CFC180
Pelvis position w.r.t. IS
Pelvis_pos
x
y
z
CFC180
x
y
z
CFC180
Left knee position w.r.t. IS
KneeS_pos
10)
73
Signal
Release 7.6
Identifier
Degree of freedom
D1/R1
D1/R2
D1/R3
Filter
Left/Right ankle position w.r.t.
IS
AnkleS_pos10)
x
y
z
CFC180
Head CG velocity w.r.t. IS
HeadCG_vel
x
y
z
CFC180
Head CG disp. w.r.t. T1
HeadCG_T1_dis
x
y
z
CFC1000
Head OC disp. w.r.t. T1
HeadOC_T1_dis
x
y
z
CFC1000
Fore/aft
shear
Lateral
shear
Tension
CFC1000
x
y
z
CFC600
Left/Right knee
shear/compression
KneeS_dis
10)
Sternum displacement/velocities Sternum_T1_dvl
w.r.t. T1
Chest distance/velocity at rib n
w.r.t. spine
Ribsn_Spine_dvl4)
x
CFC180
Lateral chest distance/velocity
at left rib n w.r.t. spine
RibnL_Spine_dvl5)
y
CFC180
Lateral chest distance/velocity
at right rib n w.r.t. spine
RibnR_Spine_dvl5)
y
CFC180
Chest relative deflection at rib n Ribsn_Spine_dis4)
w.r.t. spine
x
CFC600
Lateral chest relative deflection
RibnL_Spine_dis5)
x
CFC600
Lateral chest relative deflection
RibnR_Spine_dis5)
x
CFC600
Chest compression
ChestDeflection_dis12)
x
CFC600
Upper neck force
Upper neck force
Upper neck torque
Head OC force
NeckUp_lce_F_CFC600
NeckUp_lce_F
x
y
z
CFC600
6)
x
y
z
CFC1000
6)
6)
x
6)
NeckUp_lce_T
HeadOC_lce_F
Head OC torque
HeadOC_lce_T
Cn force
Cn _lce_F6,7)
Cn torque
Tn force
Tn torque
Ln force
Ln torque
Left/Right hip force
74
6)
x
y
y
z
z
CFC1000
CFC1000
6,7)
6,8)
x
6,8)
6,9)
x
6,9)
Cn _lce_T
Tn _lce_F
Tn _lce_T
Ln _lce_F
Ln _lce_T
6,10)
HipS_lce_F
x11)
y
y
y11)
z
z
z
CFC1000
CFC1000
CFC600
Signal
Release 7.6
Identifier
Left/Right femur force
Left/Right femur torque
Degree of freedom
D1/R2
D1/R3
FemurS_lce_F6,10)
x
y
z
CFC600
6,10)
FemurS_lce_T
Left/Right upper tibia force
Left/Right upper tibia torque
Left/Right mid tibia force
x
y
z
CFC600
6,10)
x
y
z
CFC600
6,10)
TibiaUpS_lce_F
TibiaUpS_lce_T
x
y
z
CFC600
6,10)
x
y
z
CFC600
6,10)
x
y
z
CFC600
6,10)
x
y
z
CFC600
6,10)
x
y
z
CFC600
TibiaMidS_lce_F
Left/Right mid tibia torque
Left/Right low tibia force
TibiaMidS_lce_T
TibiaLowS_lce_F
Left/Right low tibia torque
Filter
D1/R1
TibiaLowS_lce_T
1
Acceleration outputs are corrected for acceleration fields in x and y
3)
n=1 to 4, from proximal to distal.
4
) n = 1 to 4, from lower to upper.
5
6
) These output signals are used for calculation of the load cell output and for injury criteria. The force
output can be found in the RTF file and the torque output in the RTT file. It is recommended not to use
these signals, but the load cell output as listed in Table 3.13.
7
) n = 1 to 7, neck vertebrae from upper to lower.
8
) n = 1 to 12, thoracic vertebrae from upper to lower.
9
) n = 1 to 5, lumbar vertebrae from upper to lower.
10
) S = L or R, for left or right leg.
11
) Hip joint orientations are: x is lateral y is frontal.
12
) Analogous to Hybrid-III chest deflection signal.
2)
Table 3.13
Facet active human model load cell output (in injury file).
Signal
Identifier
Upper neck force
NeckUp_Fdir_lce1)
Upper neck torque
Head OC force
Head OC torque
Cn force
Cn torque
Tn force
Tn torque
Degree of freedom
D1/R1
D1/R2
D1/R3
x
y
z
1)
Roll right
Pitch down Yaw left
CFC600
1)
x
y
CFC1000
Roll right
Pitch down Yaw left
CFC600
x
y
CFC1000
Roll right
Pitch down Yaw left
CFC600
x
y
CFC1000
Roll right
Pitch down Yaw left
NeckUp_Mdir_lce
HeadOC_Fdir_lce
HeadOC_Mdir_lce
Cn _Fdir_lce
1,2)
Cn _Mdir_lce
Tn _Fdir_lce
1,2)
1,3)
Tn _Mdir_lce
1,3)
Filter
1)
z
z
z
CFC1000
CFC600
75
Signal
Release 7.6
Identifier
Degree of freedom
Ln _Fdir_lce1,4)
Ln force
Ln torque
Ln _Mdir_lce
1,4)
HipS_Fdir_lce
D1/R2
D1/R3
x
y
z
Roll right
1,5)
FemurS_Fdir_lce
D1/R1
x
1,5)
FemurS_Mdir_lce
1,5)
1,5)
6)
CFC1000
Pitch down Yaw left
6)
Filter
CFC600
y
z
CFC600
x
y
z
CFC600
x
y
z
CFC600
x
y
z
CFC600
Left/Right upper tibia
force
TibiaUpS_Fdir_lce
torque
TibiaUpS_Mdir_lce1,5)
x
y
z
CFC600
Left/Right mid tibia
force
TibiaMidS_Fdir_lce1,5)
x
y
z
CFC600
torque
TibiaMidS_Mdir_lce1,5)
x
y
z
CFC600
Left/Right low tibia
force
TibiaLowS_Fdir_lce1,5)
x
y
z
CFC600
torque
TibiaLowS_Mdir1,5)
x
y
z
CFC600
1
) dir = res, x, y, z.
3
4
5
6
2
Table 3.14
Facet active human model sensor/controller output (in control file).
Signal
Identifier
Type
Filter
Head roll angle
head_RX
Operator
None
Head pitch angle
head_RY
Operator
None
Head yaw angle
head_RZ
Operator
None
Sensor
None
Sensor
None
Sensor
None
Sensor
None
Sensor
None
Tn forward bending angle
Tn lateral bending angle
Tn torsion angle
Ln forward bending angle
Ln lateral bending angle
76
Tn_RYfwd_sensor
Tn_RXlat_sensor
1)
Tn_RZtor_sensor
1)
Ln_RYfwd_sensor
Ln_RXlat_sensor
2)
1)
2)
Release 7.6
Signal
Identifier
Ln torsion angle
Ln_RZtor_sensor
Hip (fore/aft) flexion angle
2)
HipS_flexion_sensor
Hip (lateral) abduction angle
3)
HipS_abduction_sensor
Hip (axial) rotation angle
HipS_rotation_sensor
3)
3)
3)
Type
Filter
Sensor
None
Sensor
None
Sensor
None
Sensor
None
Sensor
None
Elbow flexion angle
ElbowS_sensor
Radio-ulnar rotation angle (lower arm axial rotation)
RUS_sensor3)
Sensor
None
Head roll activation level
Head_Roll_act
Operator
None
Head pitch activation level
Head_Pitch_act
Operator
None
Head yaw activation level
Head_Yaw_act
Operator
None
Tn forward bending activation level
Tn_RYfwd_act
Tn lateral bending activation level
Tn torsion activation level
Ln forward bending activation level
Operator
None
Tn_RXlat_act
1)
Operator
None
Tn_RZtor_act
1)
Operator
None
Operator
None
Operator
None
Operator
None
Operator
None
Operator
None
Operator
None
Operator
None
Operator
None
Ln_RYfwd_act
Ln lateral bending activation level
Ln torsion activation level
Hip (fore/aft) flexion activation level
1)
2)
Ln_RXlat_act
2)
Ln_RZtor_act
2)
HipS_flexion_act
3)
Hip (lateral) abduction activation level
HipS_abduction_act
Hip (axial) rotation activation level
HipS_rotation_act3)
Elbow flexion activation level
ElbowS_act
Radio-ulnar rotation activation level
RUS_act
3)
3)
3)
1
3
) S = L or R, for left or right arm/hip.
2
Table 3.15
Injury criteria of the facet active human model.
Injury criteria
Identifier
Filter
HIC15_inj2)
CFC1000
2)
CFC1000
HIC36_inj
Head
Chest
Chest
Con3ms_HeadCG_inj2)
Con3ms_Sternum_inj
2)
CFC1000
2)
CFC180
CFC1000
77
Injury criteria
T1
T12
Pelvis
Release 7.6
Identifier
Filter
Con3ms_T1_inj
2)
Con3ms_T12_inj
CFC1000
2)
Con3ms_Pelvis_inj
CFC1000
2)
CFC1000
Head
Cum3ms_HeadCG_inj2)
CFC1000
Chest filtered
Cum3ms_Sternum_CFC180_inj2)
CFC180
Chest
T1
T12
Pelvis
Cum3ms_Sternum_inj
Cum3ms_T1_inj
2)
2)
Cum3ms_T12_inj
CFC1000
2)
Cum3ms_Pelvis_inj
CFC1000
CFC1000
2)
1,2,3)
CFC1000
rib layer n
VCRibsn_inj
CFC180
Lateral Viscous Injury Response
Criterion for left rib layer n
VCRibnL_inj1,2,4)
CFC180
Criterion for right rib layer n
VCRibnR_inj1,2,4)
CFC180
FNICTension_inj1)
CFC1000
Neck NIC Forward:
Tension
Shear
Bending
FNICShear_inj
1)
FNICBending_inj
CFC1000
1)
CFC1000 (force)
CFC600 (torque)
NIC_rearward_C1_T11,2)
CFC60
Nij Tension-extension
NTE_inj1,2)
CFC600 (force)
CFC600 (torque)
Nij Tension-flexion
NTF_inj1,2)
CFC600 (force)
CFC600 (torque)
Nij Compression-extension
NCE_inj1,2)
CFC600 (force)
CFC600 (torque)
Nij Compression-flexion
NCF_inj1,2)
CFC600 (force)
CFC600 (torque)
Nkm Flexion-anterior
NFA_inj1,2)
CFC600 (force)
CFC600 (torque)
Nkm Extension-anterior
NEA_inj1,2)
CFC600 (force)
CFC600 (torque)
Neck NIC Rearward:
Neck combined injury criteria:
78
Injury criteria
Release 7.6
Identifier
Filter
Nkm Flexion-posterior
NFP_inj
1,2)
CFC600 (force)
CFC600 (torque)
Nkm Extension-posterior
NEP_inj1,2)
CFC600 (force)
CFC600 (torque)
Combined Thoracic Index:
Upper sternum
for rib layer n
for left rib layer n
for right rib layer n
CTISternum_inj 2)
CTIRibsn_inj 1,2,3)
CTIRibnL_inj 1,2,4)
CTIRibnR_inj 1,2,4)
Left Femur Force Criterion
FFCL_inj1)
CFC600
1)
CFC600
Right Femur Force Criterion
FFCR_inj
1
) This injury output can be found in the INJURY file.
3
4
2
3.3.6
Active behaviour control
This human model contains active behaviour. Sensors in the model measure the
human positions. Based on these sensors, the control systems determine the activation
levels of various active elements in the model (muscles and actuators).
The behaviour of the controllers can be adapted in the user file by changing the
following items:




DEFINE values (CONTROL_ANALYSIS.TIME)
Neck co-contraction time history
target angle time histories (FUNCTIONS in SYSTEM.MODEL)
initial activation levels (SIGNAL.CONSTANT in CONTROL_SYSTEM in
SYSTEM.MODEL)
For each active body part, a DEFINE is present in the user file which can be used to
switch the active behaviour on (VALUE=1, default) or off (VALUE=0). In the
validation of the active human model, for all volunteer tests these DEFINE’s are set
to 1, while for all cadaver tests these DEFINE’s are set to 0. These DEFINE’s are:


Neck_activation_par (3 DOF)
Spine_activation_par (17x3 DOF)
79


Release 7.6
Hip_activation_par (2x3 DOF)
Elbow_activation_par (2x1 DOF)
The following DEFINE’s are specifically for the neck controller:
 Head_ref_par [0 | 1]: Select whether the head rotation is calculated relative to
the reference space (value=0) or relative to T1 (value=1). If head control is
assumed to be based mainly on vestibular input (balance), Head_ref_par
should be 0, to keep the head upright. This is the default for the sitting
model. If head control is assumed to be based mainly on proprioceptive input
(muscle elongations), Head_ref_par should be 1, to keep the neck straight.
This is the default for the standing model, as in a pedestrian, bicycle or
motorcycle accident due to large body rotations the head cannot be kept
upright and keeping the neck straight is in these cases assumed to be more
realistic.
 Neck_CCR [0, 1]: This is the neck co-contraction ratio. It can vary between 0
(no co-contraction, default) and 1 (full co-contraction, with maximum
activation of the flexor muscles). Use this DEFINE if a constant cocontraction level is used. For a variable co-contraction level, use the
FUNCTION described below.
 Neck_CCR_var [0 | 1]: This DEFINE enables (value=1) / disables (value=0,
default) the delays for the neck co-contraction. If a constant co-contraction is
used, no delays are required for the co-contraction. If a delay would be
defined, for the first part of the simulation (during the time of the delay) even
the co-contraction would be zero. To have the co-contraction active during
the
whole
simulation,
the
delays
can
be
disabled.
If a variable co-contraction is used (FUNCTION described below), the
delays should be activated by setting the value of Neck_CCR_var to 1.
 Reaction_time [0, ∞): This is the reaction time in seconds. The default is 0.1s
This time is the time it takes for the controllers to respond to new events.
This delay is not active for stabilization under constant loading. The
reaponse time is different per situation, it can be a reflex time triggered by
the onset of an acceleration (at e.g. the pelvis) or a reaction on a coming
event. Reported motor reflex delays range from 10 to 120 ms (Colebath et al.
1994, Foust et al. 1973, Reid et al. 1981, Schneider et al. 1975, Tennyson et
al. 1977). Reaction times depend on the situation and on the person involved.
 Delay_Enable [0, 1]: This DEFINE enables (value=1, default) / disables
(value=0) the delays for all controllers. For a settling simulation the
equilibrium state should be reached within the shortest possible time. Hence,
for a settling simulation the delays should be disabled by setting this value to
0.
80
Release 7.6
The FUNCTION Neck_CCR can be used to define a variable co-contraction, e.g. to
simulate an increasing co-contraction as a result of a fright response. Default this
function uses the Neck_CCR DEFINE value. To make the co-contraction variable,
this FUNCTION can be adjusted by the user. Note that in that case the
Neck_CCR_var DEFINE should be set to 1.
For all degrees of freedom of the neck, elbow and hip, a FUNCTION *_target_fun is
defined in the user file. Default, these are constant zero, to have the controller work
towards the initial conditions. If a variable target is desired (e.g. voluntary or reflex
motion), these function can be adjusted. The function value is the angle relative to the
initial conditions. So for a smooth motion the functions should start at zero.
A CONTROL_SYSTEM is included in the user file with for each controlled degree
of freedom a SIGNAL.CONSTANT defining the initial activation level. If a settling
run is performed with the controllers active, in the final equilibrium state the
controllers will have some activation level. These activation levels are available in the
output. To include these in the final simulation, the SIGNAL.CONSTANT’s can be
used. The conversion of the output data to the input in the model can be done
manually, or by means of a script which can be found on the TASS website
(www.tassinternational.com).
3.4 Examples
3.4.1
Facet mid-size male active human model settling
The example application file of the settling of the facet active human model in a seat
‘e_act50fc_settling.xml’ can be found on the TASS website (www.tassinternational.com).
This example shows the settling of the active human model in a seat. This settling is
used for positioning and initialisation of the human model in the combined pre-crash /
crash example described in 3.4.2 below.
For the settling run, the pulse, belts and airbag are removed from the model and
hysteresis is disabled for all characteristics outside of the active human model. The
predefined block with OUTPUT_JOINT_DOF, STATE.BODY, STATE.JOINT and
SWITCH.TIME is enabled. The human model is roughly set in the right position
using the INITIAL.JOINT_POS elements. The curvature of the spine is not modified,
as the sitting model has a relaxed seating position of the spine already included in
INITIAL.JOINT_POS. The active behaviour of the model is switched on, to keep the
desired position. To reduce the time needed to find an equilibrium, the delays are
disabled by setting the DEFINE Delay_Enable to 0. The hands are tied to the steering
wheel with point restraints and the wrists and radio-ulnar joints are locked to keep the
81
Release 7.6
arm in place with the hands on the steering wheel. Then the simulation is performed
with only gravity, until the model has reached its equilibrium. Then, the joint
positions from the *.jps file and the initial controller activation levels from the
*.control file can be used to initialise the human in the final model (see 3.4.2).
3.4.2
Facet mid-size male active human model in pre-crash and crash phase
The example application file of the facet active human model in a combined pre-crash
braking and crash scenario ‘e_act50fc_precrash.xml’ can be on the TASS website
(www.tassinternational.com).
The positioning and initialisation of the human model in this application is performed
by using the settling example described in section 3.4.1 above. Using XMADgic, the
initial joint positions resulting from the settling have been imported automatically into
the model. Next, the belt was fitted using the XMADgic belt fitting tool. In order to
let the controllers start at the levels reached during the settling, the activation levels in
the last timestep of the *.control file of the settling were used to define the initial
activation levels in the model. This can be done manually, or by means of a script
which can be found on the TASS website (www.tassinternational.com). The vehicle
model of this example was based on the MADYMO frontal impact application (see
MADYMO Applications manual), with some minor modifications. In the braking
phase the vehicle decelerates with 8 m/s^2 from about 80 km/h to 50 km/h. After 1
second, the crash occurs, after which the airbag and pretensioner are triggered.
82
4
Release 7.6
Facet pedestrian model
The MADYMO facet pedestrian model described in this chapter is currently released
in one body size, being a mid-size male model representing the 50th percentile male
model population (Figure 4.1). This model is identical to the standing active human
model (Chapter 3), except for the controllers, which are not included in the facet
pedestrian model.
Figure 4.1
Facet pedestrian model.
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Release 7.6
A facet mid-size male pedestrian model is available. The input is given in the files:
Mid-size male:
h_ped50fc_usr.xml
h_ped50fc_inc.xml
To run this model, the following licenses are required:
Mid-size male:
MADYMO/Human Models/Pedestrian
Since the facet pedestrian model is identical to the standing active human model
(Chapter 3), except for the active behaviour, for the model description is referred to
3.1.1 - 3.1.10.
The facet pedestrian model was validated using all post mortem human subject
(PMHS) tests described in section 3.2. Since the facet pedestrian model is identical to
the standing facet active human model without active behaviour, the responses of this
model are almost similar to that of the standing active human model in the PMHS
tests.
4.3.1
Table 4.1
Recommended integration method and time step for the facet pedestrian model.
Model
Integration method
Time step (s)
Mid-size male
EULER
<1.0E-05
4.3.2
Positioning
In order to position the facet pedestrian model, the INITIAL.JOINT_POS elements
have to be used. All joints that are needed for positioning the facet pedestrian model
are defined in the INITIAL.JOINT_POS elements in the user-file. Positions of all
other joints are defined in the include-file, and these should not be edited by the user.
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Release 7.6
A human model is by default positioned relative to the (global) reference space
coordinate system. However, the human model can be positioned relative to a body of
another system. This can be done in the CRDSYS_OBJECT ‘Human_Attachment’
and the associated ORIENTATION ‘Human_Attachment_ori’. The human
attachment element ‘Human_Attachment’ is comparable to the dummy attachment
element 'Dummy_attachment' in a dummy model, which is located at the H-point.
The orientations of the positioning joints are given in Table 4.2. In this table all
rotations are referred to with the terms pitch, roll and yaw, as well the anatomical
terms for the arms and legs. The directions given in the tables refer to positive
rotation directions. For all joints, the directions are defined with respect to their
coordinate system orientation, when the human model is in its reference position, as
shown in Figure 4.2, in which all initial rotations are equal to zero. The anatomical
terms for the rotations of the arms and legs are also in the DESCRIPTION attributes
in INITIAL.JOINT_POS in the user file.
Figure 4.2
Definition of joint translations and rotations of the facet pedestrian model in its
reference position.
85
Table 4.2
Release 7.6
Positioning joints of the facet pedestrian model.
Complete human
Human_jnt
Degree of freedom
D1 / R1
D2 / R2
D3 / R3
X / Roll right
Y / Pitch down
Z / Yaw left
Lumbar intervertebral L5_jnt
joint
X / Roll right
1)
Y / Pitch down
Z1) / Yaw left1)
,,
L4_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
L3_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
L2_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
L1_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Thoracic
intervertebral joint
T12_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T11_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T10_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T9_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T8_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T7_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T6_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T5_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T4_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T3_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T2_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
T1_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Cervical intervertebral C7_jnt
joint
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C6_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C5_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C4_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C3_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
,,
C2_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Atlanto-axial joint
C1_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Atlanto-occipital joint HeadOC_jnt
X1) / Roll right1)
Y1) / Pitch down
Z1) / Yaw left1)
Sternum joint1)
X1) / Roll right1)
86
SternumUp_jnt1)
1)
1)
Release 7.6
Degree of freedom
D1 / R1
1)
D2 / R2
1)
1)
Y / Pitch down
D3 / R3
1)
-Z1) / Yaw right1)
Left sterno-clavicular
joint1)
SternoClavicularL
_jnt1)
-X / Roll left
Right sternoclavicular joint1)
SternoClavicularR
_jnt1)
X1) / Roll right1)
Left acromioclavicular joint1)
AcromioClavicularL
_jnt1)
Roll left1)
Pitch down1)
Yaw right1)
Right acromioclavicular joint1)
AcromioClavicularR
_jnt1)
Roll right1)
Pitch down1)
Yaw left1)
Left glenohumeral
joint (shoulder)
GlenohumeralL_jnt
Adduction
(roll left)
Flexion
(yaw right)
Lateral rotation
(pitch up)
Right glenohumeral
joint (shoulder)
GlenohumeralR_jnt
Adduction
(roll right)
Flexion
(yaw left)
Lateral rotation
(pitch up)
Left elbow
ElbowL_jnt
Flexion
(yaw right)
Right elbow
ElbowR_jnt
Flexion
(yaw left)
Left radio-ulnar joint
RadioUlnarisL_jnt
Supination
(pitch down)
Right radio-ulnar joint RadioUlnarisR_jnt
Supination
(pitch down)
Left wrist
WristL_jnt
Flexion
(roll left)
Adduction
(yaw right)
Right wrist
WristR_jnt
Flexion
(roll right)
Left hip
HipL_jnt
Extension
(pitch down)
Adduction
(yaw left)
Adduction
(roll left)
Lateral rotation
(yaw left)
Right hip
HipR_jnt
Extension
(pitch down)
Adduction
(roll right)
Lateral rotation
(yaw right)
Left knee
KneeL_jnt
Adduction1)
(roll left)
Flexion
(pitch down)
Medial rotation1)
(yaw right)
Right knee
KneeR_jnt
Adduction1)
(roll right)
Flexion
(pitch down)
Medial rotation1)
(yaw left)
Left ankle
AnkleL_jnt
Lateral rotation
(yaw left)
Plantarflexion
(pitch down)
Inversion
(roll left)
Right ankle
AnkleR_jnt
Lateral rotation
(yaw right)
Plantarflexion
(pitch down)
Inversion
(roll right)
Left shoe joint1)
ShoeL_jnt1)
X1) / Roll right1)
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Release 7.6
Degree of freedom
D1 / R1
Right shoe joint
1)
ShoeR_jnt
1)
1)
X / Roll right
D2 / R2
1)
1)
Y / Pitch down
D3 / R3
1)
Z1) / Yaw left1)
1
) Not to be changed during manual positioning. Only for equilibrium, based on a settling simulation.
4.3.3
Contacts
Table 4.3
Available contact groups in the facet pedestrian model to define contact with its
environment.
Contact description
Identifier
Set
Complete human model
HumanBody_gfe
Elements and nodes
Complete human without arms
BodyNoArms_gfe
Elements and nodes
Complete human without head
BodyNoHead_gfe
Elements and nodes
Head
Head_gfe
Elements and nodes
Neck
Neck_gfe
Elements and nodes
Thorax
Thorax_gfe
Elements and nodes
Pelvis
Pelvis_gfe
Elements and nodes
Complete left arm
ArmL_gfe
Elements and nodes
Complete right arm
ArmR_gfe
Elements and nodes
Upper left arm
Upper_ArmL_gfe
Elements and nodes
Upper right arm
Upper_ArmR_gfe
Elements and nodes
Lower left arm (incl. hand)
Lower_ArmL_gfe
Elements and nodes
Lower right arm (incl. hand)
Lower_ArmR_gfe
Elements and nodes
Complete left leg
LegL_gfe
Elements and nodes
Complete right leg
LegR_gfe
Elements and nodes
Upper left leg
Upper_LegL_gfe
Elements and nodes
Upper right leg
Upper_LegR_gfe
Elements and nodes
Lower left leg (excl. foot/shoe)
Lower_LegL_gfe
Elements and nodes
Lower right leg (excl. foot/shoe)
Lower_LegR_gfe
Elements and nodes
Left shoe
ShoeL_gfe
Elements and nodes
Right shoe
ShoeR_gfe
Elements and nodes
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4.3.4
Release 7.6
Output
The facet pedestrian model output signals, defined in the include-file, are summarised
in Table 4.4 and Table 4.5. The facet pedestrian model injury criteria, defined in the
include-file, are summarised in Table 4.6.
Table 4.4
Facet pedestrian model time history output.
Signal
Identifier
Degree of freedom
Filter
HeadCG_aac
D1/R1
D1/R2
Roll right Pitch down
T1 angular acc.
T1_aac
Yaw left CFC1000
Head w.r.t. IS angular
displacement
Head_ang
Yaw left CFC1000
T1 w.r.t. IS1) angular
displacement
T1_ang
Yaw left CFC1000
Head w.r.t. T1 angular position
Head_T1_ang
Yaw left CFC1000
Left/Right knee bending/torsion KneeS_ang
Flexion
Lateral
bending
Torsion
CFC1000
Head CG acc. w.r.t IS2)
HeadCG_acc
x
y
z
CFC1000
10)
HeadOC_ acc
x
y
z
CFC1000
2)
C1_acc_CFC60
x
y
z
CFC60
2)
T1_acc
x
y
z
CFC1000
T1_acc_CFC60
x
y
z
CFC60
T12_acc
x
y
z
CFC1000
Sternum_acc
x
y
z
CFC1000
Sternum_acc_CFC180
x
y
z
CFC180
Pelvis_acc
x
y
z
CFC1000
x
y
z
CFC1000
x
y
z
CFC1000
C1 acc. w.r.t. IS
T1 acc. w.r.t. IS
2)
D1/R3
Yaw left CFC1000
T12 acc. w.r.t. IS
2)
Sternum acc. w.r.t. IS2)
Pelvis acc. w.r.t. IS
2)
Left/Right femur acc. w.r.t. IS
Left/Right tibia acc. w.r.t. IS
2)
2)
FemurnS_acc
TibianS_acc
3,10)
3,10)
HeadCG_dis
x
y
z
CFC180
HeadOC_dis
x
y
z
CFC1000
T1 disp. w.r.t. IS
T1_dis
x
y
z
CFC1000
Head CG position w.r.t. IS
HeadCG_pos
x
y
z
CFC180
T1 position w.r.t. IS
T1_pos
x
y
z
CFC180
Pelvis_pos
x
y
z
CFC180
89
Signal
Left knee position w.r.t. IS
Release 7.6
Identifier
Degree of freedom
KneeS_pos10)
10)
Filter
D1/R1
D1/R2
D1/R3
x
y
z
CFC180
x
y
z
CFC180
Left/Right ankle position w.r.t.
IS
AnkleS_pos
Head CG velocity w.r.t. IS
HeadCG_vel
x
y
z
CFC180
Head CG disp. w.r.t. T1
HeadCG_T1_dis
x
y
z
CFC1000
Head OC disp. w.r.t. T1
HeadOC_T1_dis
x
y
z
CFC1000
Fore/aft
shear
Lateral
shear
Tension
CFC1000
x
y
z
CFC600
Left/Right knee
shear/compression
KneeS_dis
10)
Sternum displacement/velocities Sternum_T1_dvl
w.r.t. T1
Ribsn_Spine_dvl4)
x
CFC180
Lateral chest deflection/velocity RibnL_Spine_dvl5)
y
CFC180
Lateral chest deflection/velocity RibnR_Spine_dvl5)
y
CFC180
Chest deflection/velocity at rib
n w.r.t. spine
Upper neck force
Upper neck force
Upper neck torque
Head OC force
NeckUp_lce_F_CFC6006)
NeckUp_lce_F
x
y
z
CFC600
6)
x
y
z
CFC1000
6)
Yaw left CFC600
6)
x
z
6)
Yaw left CFC600
x
z
NeckUp_lce_T
HeadOC_lce_F
Head OC torque
HeadOC_lce_T
Cn force
Cn _lce_F6,7)
Cn torque
Tn force
Tn torque
Ln force
Ln torque
Left/Right upper tibia force
Left/Right upper tibia torque
Left/Right mid tibia force
90
y
y
CFC1000
CFC1000
6,7)
Yaw left CFC600
6,8)
x
z
6,8)
Yaw left CFC600
6,9)
x
z
6,9)
Cn _lce_T
Tn _lce_F
Tn _lce_T
Ln _lce_F
Ln _lce_T
6,10)
y
11)
HipS_lce_F
FemurS_lce_F
y
11)
CFC1000
CFC1000
Yaw left CFC600
x
y
z
CFC600
6,10)
x
y
z
CFC600
6,10)
FemurS_lce_T
TibiaUpS_lce_F
x
y
z
CFC600
6,10)
x
y
z
CFC600
6,10)
x
y
z
CFC600
x
y
z
CFC600
TibiaUpS_lce_T
TibiaMidS_lce_F
6,10)
Signal
Release 7.6
Identifier
Left/Right mid tibia torque
Left/Right low tibia force
Degree of freedom
D1/R2
D1/R3
TibiaMidS_lce_T6,10)
x
y
z
CFC600
6,10)
x
y
z
CFC600
6,10)
x
y
z
CFC600
TibiaLowS_lce_F
Left/Right low tibia torque
Filter
D1/R1
TibiaLowS_lce_T
1
Acceleration outputs are corrected for acceleration fields in x and y
3)
n=1 to 4, from proximal to distal.
4
5
6
) These output signals are used for calculation of the load cell output and for injury criteria. The force
output can be found in the RTF file and the torque output in the RTT file. It is recommended not to use
these signals, but the load cell output as listed in Table 3.13.
7
8
9
10
11
2)
Table 4.5
Facet pedestrian model load cell output (in injury file).
Signal
Identifier
Upper neck force
NeckUp_Fdir_lce1)
Upper neck torque
Degree of freedom
D1/R1
x
D1/R2
y
1)
Roll right
Pitch down Yaw left
CFC600
1)
x
y
CFC1000
Roll right
Pitch down Yaw left
CFC600
x
y
CFC1000
Roll right
Pitch down Yaw left
CFC600
x
y
CFC1000
Roll right
Pitch down Yaw left
CFC600
x
y
CFC1000
Roll right
Pitch down Yaw left
NeckUp_Mdir_lce
Head OC force
HeadOC_Fdir_lce
Head OC torque
HeadOC_Mdir_lce1)
Cn force
Cn torque
Tn force
Tn torque
Ln force
Ln torque
Cn _Fdir_lce
1,2)
Cn _Mdir_lce
Tn _Fdir_lce
1,3)
Tn _Mdir_lce
Ln _Fdir_lce
1,2)
1,3)
1,4)
Ln _Mdir_lce
1,4)
HipS_Fdir_lce
1,5)
FemurS_Fdir_lce
6)
1,5)
FemurS_Mdir_lce
1,5)
6)
D1/R3
z
Filter
z
z
z
z
CFC1000
CFC600
x
y
z
CFC600
x
y
z
CFC600
x
y
z
CFC600
91
Signal
Release 7.6
Identifier
Degree of freedom
D1/R1
D1/R2
D1/R3
Filter
force
TibiaUpS_Fdir_lce1,5)
x
y
z
CFC600
torque
TibiaUpS_Mdir_lce1,5)
x
y
z
CFC600
force
TibiaMidS_Fdir_lce1,5)
x
y
z
CFC600
torque
TibiaMidS_Mdir_lce1,5)
x
y
z
CFC600
force
TibiaLowS_Fdir_lce1,5)
x
y
z
CFC600
torque
TibiaLowS_Mdir1,5)
x
y
z
CFC600
1
) dir = res, x, y, z.
3
4
5
6
2
Table 4.6
Injury criteria of the facet pedestrian model.
Injury criteria
Identifier
Filter
HIC15_inj2)
CFC1000
2)
CFC1000
HIC36_inj
Head
Chest
Chest
T1
T12
Pelvis
Con3ms_HeadCG_inj2)
Con3ms_Sternum_inj
Con3ms_T1_inj
CFC1000
2)
2)
CFC1000
2)
Con3ms_T12_inj
CFC1000
2)
Con3ms_Pelvis_inj
CFC180
CFC1000
2)
CFC1000
Head
Chest filtered
Chest
92
Cum3ms_HeadCG_inj2)
Cum3ms_Sternum_CFC180_inj
Cum3ms_Sternum_inj
2)
CFC1000
2)
CFC180
CFC1000
Injury criteria
T1
T12
Pelvis
Release 7.6
Identifier
Filter
Cum3ms_T1_inj
2)
Cum3ms_T12_inj
CFC1000
2)
Cum3ms_Pelvis_inj
CFC1000
2)
1,2,3)
CFC1000
rib layer n
VCRibsn_inj
CFC180
Criterion for left rib layer n
VCRibnL_inj1,2,4)
CFC180
Criterion for right rib layer n
VCRibnR_inj1,2,4)
CFC180
Tension
FNICTension_inj1)
CFC1000
Shear
FNICShear_inj1)
CFC1000
Neck NIC Forward:
Bending
FNICBending_inj
1)
CFC1000 (force)
CFC600 (torque)
NIC_rearward_C1_T11,2)
CFC60
Nij Tension-extension
NTE_inj1,2)
CFC600 (force)
CFC600 (torque)
Nij Tension-flexion
NTF_inj1,2)
CFC600 (force)
CFC600 (torque)
Nij Compression-extension
NCE_inj1,2)
CFC600 (force)
CFC600 (torque)
Nij Compression-flexion
NCF_inj1,2)
CFC600 (force)
CFC600 (torque)
Nkm Flexion-anterior
NFA_inj1,2)
CFC600 (force)
CFC600 (torque)
Nkm Extension-anterior
NEA_inj1,2)
CFC600 (force)
CFC600 (torque)
Nkm Flexion-posterior
NFP_inj1,2)
CFC600 (force)
CFC600 (torque)
Nkm Extension-posterior
NEP_inj1,2)
CFC600 (force)
CFC600 (torque)
Neck NIC Rearward:
Neck combined injury criteria:
Combined Thoracic Index
CTI_inj2)
Left Femur Force Criterion
FFCL_inj1)
CFC600
1)
CFC600
Right Femur Force Criterion
FFCR_inj
1
) This injury output can be found in the INJURY file.
93
2
4
3
94
Release 7.6
5
Release 7.6
Ellipsoid pedestrian models
The MADYMO ellipsoid pedestrian models described in this chapter is currently
released in five body sizes. A small female model representing the 5th percentile
female population, a mid-size male model representing the 50th percentile male model
population, and a large male model representing the 95th percentile male model are
available, and two child body sizes representing a 3 and 6-yeas-old are available
(Figure 5.1). Please note that the child occupant models are scaled from adult
anthropometries and hence they do not necessarily represent children in terms of their
biofidelic behaviour.
Figure 5.1
Ellipsoid pedestrian models, from left to right; 3-year-old child, 6-year-old
child, small female, mid-size male and large male.
95
Release 7.6
The MADYMO model names and input file names of the ellipsoid pedestrian models
are:
3-year-old child:
h_ped3yel_usr.xml
h_ped3yel_inc.xml
6-year-old child:
h_ped6yel_usr.xml
h_ped6yel_inc.xml
Small female:
h_ped05el_usr.xml
h_ped05el_inc.xml
Mid-size male:
h_ped50el_usr.xml
h_ped50el_inc.xml
Large male:
h_ped95el_usr.xml
h_ped95el_inc.xml
Besides these models, a scaleable pedestrian model is available:
Parameter model mid size male:
h_ped50el.par
Using the MADYMO/SCALER utility, this model can be scaled towards different
anthropometry data sets.
5.1.1
Anthropometry
The mid-size male pedestrian model was developed first. The anthropometry of this
model was, similar to the facet occupant models, based on the database of the
RAMSIS software package (RAMSIS, 1997). Like for the facet occupant models, the
Western European population aged 18-70 years in 1984 has been used. Afterwards,
the mid-size male pedestrian model has been scaled towards a 3-year-old child, a 6year-old child, a small female and a large male model (see Figure 5.1). The
anthropometries of the small female and large male pedestrian models were also
based on the RAMSIS database. The anthropometries of the 3- and 6-year-old child
were based on the specification of the Q child dummies. Global anthropometry
specifications are given in Table 5.1.
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Table 5.1
Release 7.6
Anthropometry of the ellipsoid pedestrian models.
Parameter
3 year
old child
6 year
old child
Small
female
Mid-size
male
Large
male
Standing height [m]
0.95
1.17
1.53
1.74
1.91
Seated height [m]
0.55
0.64
0.81
0.92
1.00
Shoulder breadth [m]
0.25
0.28
0.40
0.47
0.52
Knee height [m]
0.28
0.35
0.47
0.54
0.59
Weight [kg]
14.5
23.0
49.77
75.7
101.1
The scaling of the pedestrian models was done using MADYMO/SCALER (Happee
et al., 1998). In MADYMO/SCALER different scaling factors are specified for x-, y-,
and z-dimensions and for different body parts. Thus the model geometry can be
adapted freely to the desired anthropometry parameters. In addition to the geometry,
all other model parameters can be scaled. Based on the desired anthropometry
parameters there is scaling of:

Geometry

Mass and moments of Inertia

Joint characteristics (stiffness, friction, damping and hysteresis), including that of
protected joints

Ellipsoids and penetration characteristics

Force models

Fracture levels

Sensor locations
5.1.2
Configuration
The pedestrian models each consist of 52 rigid bodies, organised in 7 configuration
branches. The outer surface is described by 64 ellipsoids and 2 planes. The first
branch connects the head and thorax to the pelvis. The second and third branch
connect the bodies of the left and right arm to T1, respectively. The fourth and fifth
branch connect the bodies of the left and right leg to the pelvis, respectively. The
heels are each connected to the mid-foot joint by a separate branch.
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5.1.3
Release 7.6
Spine and neck
The spine and neck are modelled by 4 kinematic joints. The spine consists of 1
spherical joint at lumbar location and 1 free joint at thoracic location. The neck is
modelled by 2 free joints at the lower neck location (T1-C7) and 1 at the upper neck
(C1-Head OC) location, respectively. The free joints in the spine and neck allow
elongation. The stiffness in the different directions is modelled by six-DOF restraints
at the joint locations. The rotational stiffnesses in the spine are based on Yang et al.
(2000). The translational stiffness in the z-direction is based on the resultant
elongation stiffness of the facet occupant models. The translational stiffnesses in xand y-direction are higher than in z-direction, in order to prevent lateral translation. In
the z-direction also damping coefficients are added, which are also based on the facet
occupant models.
5.1.4
Thorax and abdomen
For application in contact with vehicle models, it was considered desirable to
represent each torso section (pelvis, abdomen, ribs, shoulder and for female also
breasts) by just one ellipsoid of sufficient size. The ellipsoids are sufficiently large to
avoid unrealistic discontinuities, when ellipsoids contact the edges of vehicle parts,
like the bonnet leading edge. In defining the ellipsoids it was already taken into
account that scaled pedestrian models should also interact realistically with vehicle
models. Using few ellipsoids also diminishes the chance on multiple contacts with
one vehicle part. When using combined contact functions, multiple contacts with one
vehicle part lead to a too high resultant stiffness.
Contact characteristics have been implemented for lateral loading of pelvis, abdomen,
ribs and shoulder. The contact characteristics (stiffness, hysteresis, damping) were
based on data found in literature and optimized in simulations of a large range of
PMHS impactor tests on various body parts, see Section 5.2. Based on various pelvis
impactor simulations, different contact stiffness characteristics were used for the
lateral and rear part of the pelvis to represent the difference in the amount of flesh in
these areas.
5.1.5
Hip
The hip joint is modelled by a spherical joint. The joint stiffness curves were taken
from the validated pedestrian model by Yang & Lovsund (1997) who selected the hip
resistance after Frankel & Nordin (1980). The joint stiffness curves were found to
agree well with ranges of motion of the RAMSIS human model (Speyer and Seidl,
1997).
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5.1.6
Release 7.6
Knee
The knee is a complex joint with a strong coupling between the degrees of freedom.
The resistance for axial rotation is, for instance, dependent on the knee flexion angle.
In principle, geometric modelling of the relevant joint surface interactions and
ligaments, muscles, and other soft tissues allows the definition of a general knee
model. However, detailed knee models for impact are still restricted in their range of
application. Therefore, the pedestrian knee is modelled by just one free joint and the
knee model characteristics have been optimized for an approximately extended
position, as this position is most relevant for pedestrian loading. Linear and non-linear
joint resistance functions have been implemented in accordance with available data
from literature.
Linear lateral bending stiffness matching the dynamic data of Kajzer et al. (1997) has
been implemented, which is significantly larger than quasi-static values reported by
Piziali & Rastegar (1977) and Markolf et al. (1976), but comparable to EEVC
requirements (EEVC, 1994). The knee flexion/extension stiffness has been
implemented using volunteer data (Engin, 1979a; Ma et al. 1995). Inward rotation of
the foot with respect to the femur has been implemented as a combination of knee and
ankle joint rotation. Using data from Engin (1979b) for both joints an identical
resistance has been implemented for axial rotation.
For knee lateral shear the EEVC (1994, 1998a) has defined an injury tolerance level
of 4 kN force and 6 mm displacement. This results in a linear stiffness of 6.7E5 N/m,
which has been applied in the pedestrian model. For pedestrian applications,
forward/rearward shear is considered of minor importance and therefore the stiffness
selected for lateral shear has also been applied for forward/rearward shear. Results
from Piziali & Rastegar (1977) indicate that this is acceptable for conditions with an
extended knee. A linear stiffness was implemented for knee axial compression based
on the initial displacement (1 mm) of PMHS data of Walker & Hajek (1972).
5.1.7
Upper and lower leg
In pedestrian impacts, leg bending and resulting bone fracture is commonly found. To
account for this in the pedestrian model, bending and fracture properties were
implemented at several locations in the femur and tibia using bending/fracture joints.
In both the upper and lower leg spherical joints have been implemented in order to
model bending and fracture. In Figure 5.2 all joint locations in the leg are specified:
the large spots show the hip, knee and ankle joints, the small spots show the locations
of the bending and/or fracture joints. The location of the middle bending joint in the
femur corresponds with the location of the femur loadcell in the Hybrid III dummy.
The locations of the upper and lower bending joints in the tibia correspond with the
locations of the tibia loadcells in the Hybrid III dummy.
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Release 7.6
hip joint
upper leg joint 2: bending
upper leg joint 3: fracture & bending
upper leg joint 4: bending
knee joint
lower leg joint 2: fracture & bending
ankle joint
Figure 5.2
Left leg with joints. The large spots are the physical joints: hip, knee and ankle.
The small spots are joints for modelling fracture and/or bending of femur and
tibia.
Cardan restraints have been implemented at all the bending joints to model the
bending stiffness of femur and tibia. Angular stiffness functions were derived from
simulations of quasi-static bending tests of Yamada (1973). The angular stiffness is
assumed to be equal throughout one long bone. Therefore, the same characteristics
have been used for all three cardan restraints within one segment.
In car-pedestrian collisions fracture most often occurs in the lower leg. Therefore,
fracture joints have been implemented at the middle upper leg joint and all three
lower leg joints. All fracture joints are spherical joints that are initially locked until a
pre-defined fracture trigger signal exceeds the fracture tolerance level. Bending
moments and shear forces were used as fracture trigger signals.
Once the fracture tolerance is exceeded, the angular resistance in the fracture joint is
set to zero and both parts of the fractured bone are free to rotate relative to each other.
Minor rotational damping was implemented in the fracture joints to avoid numerical
instabilities once fracture occurred.
An overview of the fracture tolerances found in literature is summarized in Table 5.2.
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Table 5.2
Release 7.6
Summary of leg fracture tolerances found in literature.
Shear force
(kN)
Bending
moment
(Nm)
Reference
Femur
3.9
310
Messerer (Males) 1)
4.3
160
Strømsøe, et al.
(1995) 1)
2.5
233
Weber (Males) 1)
2.6
224
Yamada (1973)
3.1
Kress et al. (1993)
6.3
430
10.0 at 4 ms
600 at 4 ms
6.5 at 10 ms
300 at 10 ms
Rodmell &
Lawrence (1998)
Liu (2003)
Tibia
3.3
207
Messerer (Males) 1)
5.0
328
Nyquist, et al.
(1985)
3.0
165
Weber (Males) 1)
194
Yamada (1973)
2.7
3.3-4.3
1)
2)
2)
Kramer (1973)
7.5 at 4 ms
450 at 4 ms
4.0 at 10 ms
250 at 10 ms
Yang, et al. (1997)
Summarized by Nyquist (1985).
Depending on the size of the impactor (5.7 - 8.5 inch diameter).
Based on these values, the fracture tolerance levels for the mid-size male pedestrian
model were chosen. The implemented fracture levels for the upper and lower leg are
based on 50% injury risk, see Table 5.3. These levels can be adapted in the model for
studying a specific population, like for instance elderly people, provided that these
tolerance levels are know for this specific population group. This can be done by
changing the values for the DEFINE elements in the user file
(Leg[Up|Low]Fract[Force|Torque]Lat[Pos|Neg])
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Table 5.3
Release 7.6
Fracture levels for the upper and lower leg, based on 50% injury risk.
Model part
Torque [Nm]
Reference
Shear force
[N]
Reference
Upper leg
55
scaled
1560
Scaled
Lower leg
50
scaled
1040
Scaled
Upper leg
140
scaled
2840
Scaled
Lower leg
85
scaled
1890
Scaled
Upper leg
265
scaled
4390
Scaled
Lower leg
240
scaled
2925
Scaled
Upper leg
430
EEVC WG17
6000
Based on EEVC
WG17
Lower leg
285
Nyquist et al. (1985)
4000
Yang et al. (2000)
Upper leg
575
scaled
7285
Scaled
Lower leg
435
scaled
4855
Scaled
3-year-old child:
6-year-old child:
Small female:
Mid-size male:
Large male:
5.1.8
Ankle, foot and shoe
For the ankle and foot a MADYMO model of the ‘soft stop foot’ of the Hybrid III is
adopted. In this model the shoes of the Hybrid III have been added as separate bodies
allowing some relative motion between feet and shoes. The shoe model is also
included in the pedestrian model.
Since the ankle rotation stiffness of the Hybrid III is still not biofidelic and
mechanical failure has been observed (Crandall et al., 1996), the ankle joint resistance
parameters of the pedestrian model were adapted using biomechanical data. In
volunteer and PMHS experiments the ankle dorsiflexion stiffness is found to depend
on the knee flexion angle. The rotational stiffness for ankle dorsiflexion was derived
from volunteer tests with extended knees (Crandall et al., 1996). The rotational
stiffness for inversion/eversion was also derived from volunteer data (Crandall et al.,
1996). Inward rotation of the foot has been implemented as a combination of knee
and ankle rotation using data from Engin (1979b).
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Release 7.6
The human pedestrian model has been validated extensively. First, one series of leg
shear and bending tests has been used (Kajzer, 1997). The contact characteristics
(stiffness, hysteresis, damping) with the various other body parts have been based on
data found in literature and optimized in simulations of a large range of PMHS
impactor tests on various body parts. Furthermore, three different sets of PMHS
pedestrian-vehicle impact tests have been simulated to verify the biofidelity of the
pedestrian model. An overview of the validation is described below. An extended
description of the validation simulations and results can be found in Hoof et al.
(2003). The implementation of a typical car-pedestrian test is described in the
‘examples’ section.
From the extended validation of the pedestrian models it can be concluded that:

The models accurately predict the global kinematics.

The models accurately predict the impact points on the vehicle, especially for
the head.

The models can reasonably predict the occurrence of fractures in the upper
and lower legs during the impact between the pedestrian and the vehicle.

The models can predict the shape and trends of the head, chest and pelvis
accelerations and the bumper forces.
5.2.1
Blunt impact tests
The blunt impact tests used for the validation of the pedestrian models are
summarised in Table 5.4. The different impactor test configurations simulated are
presented in Figure 5.3.
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Release 7.6
Figure 5.3
Different impactor test configurations used for model validation.
Table 5.4
Blunt impact tests used for validation of the pedestrian models.
Segment
Test
Reference
description
test object
specifications
Lower extremities
shear loading
impact
PMHS lower
extremities
15, 20 km/h, 40 kg
Kajzer et al. (1990),
Yang et al. (1995)
Lower extremities
bending impact
PMHS lower
extremities
16, 20 km/h, 40 kg
Kajzer et al. (1993),
Yang et al. (1995)
Pelvis
lateral impact
10 PMHSs
23.4 kg, 3.4 m/s
Bouquet (1994)
lateral impact
10 PMHSs
23.4 kg, 6.6 m/s
Bouquet (1994)
lateral impact
4 PMHSs
23.4 kg, 5.2 m/s
Viano (1989)
lateral impact
4 PMHSs
23.4 kg, 9.8 m/s
Viano (1989)
oblique impact
6 PMHSs
23.4 kg, 4.8 m/s
Viano (1989)
oblique impact
4 PMHSs
23.4 kg, 6.8 m/s
Viano (1989)
oblique impact
4 PMHSs
23.4 kg, 9.4 m/s
Viano (1989)
lateral impact
6 PMHSs
12 kg, 5.3-8.5 m/s
Talantikite (1998)
Abdomen
Thorax
104
5 PMHSs
16 kg, 5.7-7.2 m/s
Talantikite (1998)
5 PMHSs
23.4 kg, 4.3 m/s
Viano (1989)
oblique impact
5 PMHSs
23.4 kg, 6.7 m/s
Viano (1989)
oblique impact
5 PMHSs
23.4 kg, 9.3 m/s
Viano (1989)
lateral impact
7 PMHSs
23.4 kg, 5.5 m/s
Meyer (1994)
lateral impact
5 PMHSs
static
Meyer (1994)
lateral impact
oblique impact
Shoulder
5.2.2
Release 7.6
Car-pedestrian tests
The car-pedestrian tests used for the validation of the pedestrian models are
summarised in Table 5.5. Since PMHS subjects of different anthropometries were
used in the tests, the pedestrian model was scaled to the specific body dimensions of
each PMHS subject prior to simulating the corresponding test.
Table 5.5
Full body car-pedestrian impact tests used for validation of the pedestrian
models.
Model
Test
Reference
Description
Test
object
specifications
Mid-size male scaled
to PMHS size
5 tests, large
family car and
optimized car
5 PMHSs
32-39.8 km/h,
deceleration
4.7-5.7 m/s2
EEVC (1998b)
to PMHS size
10 tests, 3
different cars
10 PMHSs
25, 32, 39, 40
km/h
Ishikawa et al.
(1993)
to PMHS size
3 tests, small
family car
3 PMHSs
25, 32, 39 km/h
Yang et al. (2000)
5.3.1
The recommended integration method and minimum integration time step for the
pedestrian models is given in Table 5.6. The time step of 1.0E-05 s is sometimes
required during fracture of the leg. If the fracture joints are not used, the time step can
be set to 2.5E-05.
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Table 5.6
Release 7.6
Recommended integration method and time step for the pedestrian models.
Model
Integration method
Time step (s)
3-year-old child
EULER
≤1.0E-05
6-year-old child
EULER
≤1.0E-05
Small female
EULER
≤1.0E-05
Mid-size male
EULER
≤1.0E-05
Large male
EULER
≤1.0E-05
5.3.2
Positioning
Positioning of the pedestrian model in MADYMO is done in three steps:
1. The complete pedestrian model is positioned and orientated correctly with respect
to its environment by initialising the position and orientation of the human joint
(‘Human_jnt’), which is a free joint connecting the pedestrian model to its
environment. The pedestrian model must be placed at a position such that the
shoes touch the ground.
2. The extremities and other pedestrian model segments are orientated with respect
to the parent segment by changing the orientation of the corresponding bodies in
the positioning element (JOINT_DOF). The pedestrian model can for example be
put in a walking position.
3. Contact has to be defined between the pedestrian shoes and the ground. An
equilibrium between the gravitational force and the ground contact force acting
on the pedestrian model will have to be obtained. This can be done by performing
short simulations the pedestrian in a gravitational field and change the initial
position of the Human_jnt, until the pedestrian stands still.
When all joints in INITIAL.JOINT_POS are set to zero (except for the ankles), the
pedestrian model is in an erect standing position as is shown in Figure 5.4. This
position is called the reference position. In this position the joint translations and
rotations are defined as shown in Figure 5.4.
The orientations of the translational (D) and rotational (R) DOF of the pedestrian
model positioning joints are given in Table 5.7. The positioning joints are
schematically drawn in Figure 5.5.
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Release 7.6
The fracture joints in the legs can be switched off by disabling the STATE.JOINT
element in the user-file.
z
yaw left
pitch down
y
x
Figure 5.4
roll right
Definition of joint translations and rotations of the pedestrian models. The
pedestrian is in its reference position.
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Release 7.6
NeckUp-Head
NeckLow-NeckUp
TorsoUp-NeckLow
Shoulder
LumbarUp-TorsoUp
Elbow
LumbarLow-LumbarUp
Human joint
Hip
Wrist
Knee
Ankle
Figure 5.5
108
Locations of the positioning joints of the pedestrian model.
Table 5.7
Release 7.6
Positioning joints of the pedestrian models.
Joint
description
Identifier
Degree of freedom
Complete human
Human_jnt
D1 / R1
X / Roll right
Lower lumbar joint
LumbarLow-LumbarUp_jnt
Yaw right
Pitch down
Roll right
Upper lumbar joint
LumbarUp-TorsoUp_jnt
Roll right
Pitch down
Yaw left
T1
TorsoUp-NeckLow_jnt
Pitch down
Neck joint
NeckLow-NeckUp_jnt
Roll right
Pitch down
Yaw left
Head OC
NeckUp-Head_jnt
Roll right
Pitch down
Yaw left
Hip
HipS_jnt
Roll right
Pitch down
Yaw left
Knee
KneeS_jnt1)
Pitch down
Roll left
Yaw left
Ankle
AnkleS_jnt
Yaw left
Roll right
Pitch down
Shoulder
ShoulderS_jnt
Pitch down
Roll right
Elbow
ElbowS_jnt
Yaw left
Pitch down
Wrist
WristS_jnt
Yaw left
Roll right
1)
D2 / R2
Y / Pitch down
D3 / R3
Z / Yaw left
S = L or R, stands for left and right side, respectively.
5.3.3
Contacts
The available contact groups (in the include-file) that can be used to define contact
between the pedestrian and its environment in the user-file are summarised in Table
5.8.
Since a lot of ellipsoids are defined for the legs and the thorax, it is very important to
carefully choose the contact between the ellipsoids of the pedestrian and the
contacting surface of the vehicle or the road.
It is recommended to very carefully use the EVALUATIONS option for ellipsoidellipsoid contact. If this option is used, the complete contact force can switch from
one ellipsoid to another and back depending on the ellipsoid that is most penetrated.
With this switching of the contact force, large unrealistic vibrations can be
introduced.
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Table 5.8
Release 7.6
Available contact groups in the pedestrian models to define contact with their
environment.
Contact description
Identifier
Head
Head_gmb
Ellipsoid / plane model
Head_ell
1)
Upper arms
ArmUpS_gmb
Lower arms
ArmLowS_gmb
Shoulders
Shoulders_gmb
Collar_ell ShoulderL_ell
ShoulderR_ell
Thorax sides
ThoraxLateral_gmb
RibsAllLateral_ell
Abdomen sides
AbdomenLateral_gmb
AbdomenMidLateral_ell
Pelvis
Pelvis_gmb
TorsoLowLateral_ell
PelvisLateral_ell HipL_ell
HipR_ell
Upper legs
LegUpS_gmb
LegUp1S_ell LegUp2S_ell
LegUp3S_ell
Lower legs
LegLowS_gmb
LegLow1S_ell LegLow2S_ell
LegLow3S_ell LegLow4S_ell
Shoes
ShoeS_gmb
ShoeS_ell FrontShoeS_ell
HeelShoeS_ell
Upper torso
TorsoUp_gmb
TorsoUpL_ell TorsoUpR_ell
Front part of shoes
FrontShoeS_gmb
FrontShoeS_ell
Inner part of shoe soles
ShoeInrSoleS_gmb
ShoeInrSoleS_pln
Heels
HeelS_gmb
HeelS_ell
Toes
ToesS_gmb
ToesS_ell
1)
ArmUpS_ell
ArmLowS_ell HandS_ell
5.3.4
Output
The pedestrian model output signals, defined in the include-file, are summarised in
Table 5.9 and Table 5.10. The pedestrian model injury criteria, defined in the includefile, are summarised in Table 5.11. Note that the output in specified directions is in
the injury output file.
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Table 5.9
Release 7.6
Ellipsoid pedestrian models output.
Signal
Identifier
D1 / R1
D2 / R2
D3 / R3
Head CG vel. w.r.t. IS6)
HeadCG_lvl
x
y
z
CFC180
HeadCG_lds
x
y
z
CFC180
Sternum relative vel. w.r.t.
upper torso
Sternum_dvl
x
y
z
CFC180
Sternum disp. w.r.t. IS
Sternum_lds
x
y
z
CFC180
Pelvis_pos
x
y
z
CFC180
Knee position w.r.t. IS
KneeS_pos
x
y
z
CFC180
Foot position w.r.t. IS
FootS_pos
x
y
z
CFC180
Head CG acc.
HeadCG_lac
x
y
z
CFC1000
Sternum acc.
Sternum_lac
x
y
z
CFC1000
Upper torso acc.
TorsoUp_lac
x
y
z
CFC1000
Lower torso acc.
TorsoLow_lac
x
y
z
CFC1000
Upper leg 2 acc.
1)
LegUp2S_lac
x
y
z
CFC1000
LegLow3S_lac
x
y
z
CFC1000
HipS
Roll right
Pitch down
Yaw left
Knee cardan output
KneeS
Roll right
Pitch down
Yaw left
CFC180
Knee shear
KneeShearS
Frontal
shear
Lateral
shear
Axial
CFC180
Ankle cardan output
AnkleS
Roll right
Pitch down
Yaw left
Lower torso force
TorsoLowLumbarLow_Force3)
x
y
z
CFC1000
Lower torso torque
TorsoLowLumbarLow_Torque3)
Roll right
Pitch down
Yaw left
CFC1000
Lower neck force
NeckLow_Force3)
x
y
z
CFC1000
Roll right
Pitch down
Yaw left
CFC600
x
y
z
CFC1000
Roll right
Pitch down
Yaw left
CFC600
x
y
z
CFC600
Yaw left
Pitch up
Roll left
CFC600
x
y
z
CFC600
Roll right
Pitch down
Yaw left
CFC600
Lower leg 3 acc.
Hip cardan output
2)
Lower neck torque
Upper neck forces
Upper neck torque
Degree of freedom
NeckLow_Torque
NeckUp_Force
3)
3)
NeckUp_Torque
3)
3)
Upper leg 3 forces
LegUp3S_Force
Upper leg 3 torque
LegUp3S_Torque3)
Lower leg n force
Lower leg n torque
LegLownS_Force
3,4)
LegLownS_Torque
3)
Filter
111
Signal
Identifier
Upper leg 3 lateral torque5) LegUp3S_TorqueLat
Lower leg n lateral torque
Upper leg 3 lateral force
2)
5)
Degree of freedom
Filter
D1 / R1
D2 / R2
D3 / R3
Yaw left
Pitch up
Roll left
CFC600
LegLownS_TorqueLat
Roll right
Pitch down
Yaw left
CFC600
5)
LegUp3S_ForceLat
x
y
z
CFC600
5)
LegLownS_ForceLat
x
y
z
CFC600
Lower leg n lateral force
1)
Release 7.6
Note that the cardan output is given in successive rotations. The cardan output can be found in the
CAN file.
3
) These output signals are used for calculation of the neck, torso and leg output specified in directions.
The forces can be found in the FRC file, and the torques in the RTT file. It is recommended to use the
specified neck, torso and leg output, see Table 5.10.
4)
n = 2, 3 or 4, see Figure 5.2.
5)
Used as trigger signals for the fracture joints
6)
IS=Inertial System
Table 5.10
Pedestrian models load cell output of torso, lower and upper neck and legs in
specified directions.
Signal
Identifier
Degree of freedom
D1 / R1
D2 / R2
Filter
D3 / R3
Spec. lower torso force:
Resultant
TorsoLowLumbarLow_FRES
For-rearward shear
TorsoLowLumbarLowFX_SHEAR
Lateral shear
TorsoLowLumbarLowFY_SHEAR
Axial
TorsoLowLumbarLowFZ_AXIAL
CFC 1000
x
CFC 1000
y
CFC 1000
z
CFC 1000
Spec. lower torso torque:
Resultant
TorsoLowLumbarLow_MRES
Lateral
TorsoLowLumbarLowMX_ROLL
For-rearward
TorsoLowLumbarLowMY_PITCH
Axial
TorsoLowLumbarLowMZ_YAW
112
CFC 1000
Roll right
CFC 1000
Pitch down
CFC 1000
Yaw left
CFC 1000
Signal
Release 7.6
Identifier
Degree of freedom
D1 / R1
D2 / R2
Filter
D3 / R3
Spec. lower neck force:
CFC 1000
Resultant
NeckLowFRES
CFC 1000
For-rearward shear
NeckLowFX_SHEAR
Lateral shear
NeckLowFY_SHEAR
Axial
NeckLowFZ_AXIAL
x
CFC 1000
y
CFC 1000
z
CFC 1000
Spec. lower neck torque:
Resultant
NeckLowMRES
CFC 600
Lateral
NeckLowMX_ROLL
For-rearward
NeckLowMY_PITCH
Axial
NeckLowMZ_YAW
Roll right
CFC 600
Pitch down
CFC 600
Yaw left
CFC 600
Spec. upper neck force:
Resultant
NeckUpFRES
For-rearward shear
NeckUpFX_SHEAR
Lateral shear
NeckUpFY_SHEAR
Axial
NeckUpFZ_AXIAL
CFC 1000
x
CFC 1000
y
CFC 1000
z
CFC 1000
Spec. upper neck torque:
Resultant
NeckUpMRES
Lateral
NeckUpMX_ROLL
For-rearward
NeckUpMY_PITCH
Axial
NeckUpMZ_YAW
CFC 600
Roll right
CFC 600
Pitch down
CFC 600
Yaw left
CFC 600
Spec. upper leg 3 force:
Resultant
For-rearward shear
Lateral shear
Axial
LegUp3S_FRES1)
CFC 600
1)
LegUp3S_FX_SHEAR
x
1)
LegUp3S_FY_SHEAR
CFC 600
y
1)
LegUp3S_FZ_AXIAL
CFC 600
z
CFC 600
Spec. upper leg 3 torque:
Resultant
Lateral
For-rearward
Axial
LegUp3S_MRES1)
CFC 600
1)
LegUp3S_MX_ROLL
1)
LegUp3S_MY_PITCH
1)
LegUp3S_MZ_YAW
Roll right
CFC 600
Pitch down
CFC 600
Yaw left
CFC 600
Spec. lower leg n force:
113
Signal
Release 7.6
Identifier
Degree of freedom
D1 / R1
D2 / R2
LegLownS_FRES1,2)
Resultant
For-rearward shear
CFC 600
1,2)
LegLownS_FX_SHEAR
x
1,2)
Lateral shear
LegLownS_FY_SHEAR
CFC 600
y
CFC 600
1,2)
Axial
Filter
D3 / R3
LegLownS_FZ_AXIAL
z
CFC 600
Spec. lower leg n torque:
LegLownS_MRES1,2)
Resultant
Lateral
LegLownS_MX_ROLL
LegLownS_MY_PITCH
CFC 600
Pitch down
1,2)
Axial
2)
Roll right
1,2)
For-rearward
1)
CFC 600
1,2)
LegLownS_MZ_YAW
CFC 600
Yaw left
CFC 600
n = 2, 3 or 4, see Figure 5.2.
Table 5.11
Injury criteria of the pedestrian models.
Injury criteria
Identifier
HIC_inj
Filter
1)
CFC1000
Head
Torso
Con3msHeadCG_inj1)
CFC1000
1)
CFC1000
Con3msTorsoUp_inj
Head
Cum3msHeadCG_inj1)
CFC1000
Torso
Cum3msTorsoUp_inj1)
CFC1000
Viscous Injury Response
Criterion for sternum
VCSternum_inj
1)
CFC180
1
5.4 Example
5.4.1
Car-pedestrian impact
The example application file of a car-pedestrian impact ‘e_ped50el.xml’ can be found
in $MADHOME/share/appl/3d.
114
Release 7.6
In this example a 32 km/h impact of a car against a pedestrian has been simulated.
The vehicle model represents a 880 kg small family car and consists of six ellipsoids.
The bumper, the hood, the hood-edge and the windscreen are represented by one
ellipsoid each, and the wheels by two ellipsoids. The location of the center of gravity
and moments of inertia of the car model were approximated, based on the onedimensional nature of the car motion. The dynamic characteristics of the bumper
system (force-penetration for the contact) were based on results from legform to
bumper impact tests by Schueler and Glasson (1998). The mechanical properties of
the windscreen were based on the static data published by Yang et al. (2000).
115
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References
Berkson, M.H., Nachemson A., Schultz A.B. (1979): Mechanical properties of the
human lumbar spine motion segments – Part II: Responses in compression and
shear; influence of gross morphology. Journal of Biomechanical Engineering,
Vol. 101, pp 53-57.
Bertholon N. (1999): Modelisation 3D du cou humain en situation de chocs
omnidirectionelles. Analyse Cinématique et aspects lésionnels, PhD-thesis,
l’École National Supérieur d’Arts et Metiers, Paris.
Bertholon N., Robin S., Le-Coz J-Y. (2000): Human head and cervical spine
behaviour during low-speed rear-end impacts: PMHS sled tests with a rigid seat.
IRCOBI Conference.
Bouquet R., Ramet M., Bermond F., Cesari D. (1994): Thoracic and pelvis response
to impact. Proceedings of the 14th International Technical Conference on the
enhanced safety of vehicles, pp. 100-109, No 94-S1-O-03.
Brouwn G.G. (2000): Postural control of the human arm. PhD-thesis, Delft University
of Technology.
Budziszewski P., Nunen E. van, Mordaka J.K., Krzysztof K. (2008): Active
controlled muscles in numerical model of human arm for movement in two
degrees of freedom. IRCOBI Conference.
Camacho D.L., Nightingale R.W., Robinette J.J., Vanguri S.K., Coates D.J., and
Myers B.S. (1997): Experimental flexibility measurements for the development
of a computational head-neck model validated for near-vertex head impact. In:
Proceedings of the 41st Stapp Car Crash Conference, pp. 473-486, Society of
Automotive Engineers, SAE paper No. 973345.
Cappon H.J., Mordaka J., van Rooij L., Adamec J., Praxl N., Muggenthaler H.(2007):
A computational human model with stabilizing spine: a step towards active
safety, SAE paper 2007-01-1171.
Cappon H., Kroonenberg R., Happee R., Wismans J. (1999): An Improved Lower
Leg Multibody Model, Proceedings of IRCOBI Conference, Sitges, Spain, pp.
499-512.
Cavanaugh J.M., Nyquist G.W., Goldberg S.J., King A.I. (1986): Lower abdominal
tolerance and response. SAE paper 861878.
Colebatch J.G., Halmagyi G.M., and Skuse N.F. (1994): Myogenic potentials
generated by a click-evoked vestibulocollic reflex. Journal of Neurology,
Neurosurgery, and Psychiatry, 57:190–197.
116
Release 7.6
Crandall J.R., Portier L., Petit P., Hall G.W., Bass C.R., Klopp G.S., Hurwitz S.,
Pilkey W.D., Trosseille X., Tarriere C., Lassau J.P. (1996): Biomechanical
response and physical properties of the leg, foot and ankle. Stapp Car Crash
Conference, SAE paper 962424.
Daniel et al. (1995): Technical specifications of the SID-IIS Dummy. SAE paper
952735.
Davidsson J., Svensson M.Y., Flogård A. et al. (1998). A new biofidelic rear impact
dummy, IRCOBI Conference.
Delp, S.L., Loan, J.P., Hoy, M.G., Zajac, F.E., Topp E.L., Rosen, J.M. (1990): An
interactive graphics-based model of the lower extremity to study orthopaedic
surgical procedures, IEEE Transactions on Biomedical Engineering, Vol. 37, pp.
757-767.
Deng Y.-C and Goldsmith W. (1987): Response of a human head/neck/upper-torso
replica to dynamic loading - II. analytical/numerical model. Journal of
Biomechanics, 20, pp. 487-497.
Don, B. van, Ratingen, M. van Bermond, F., Masson, C., Vezin, P., Hynd, D., Owen,
C., Martinez, L., Knack, S., Schaefer (2003): Biofidelity impact response
requirements for an advanced mid-sized male crash test dummy, Proceedings of
the 18th International Technical Conference on Enhanced Safety of Vehicles
(ESV), Paper no. 79.
Eberlein R., Frohlich M., and Hasler E.M. (1999): Finite-element-analyses of
intervertebral discs: Structural components and properties. In: ECCM
Proceedings of European Conference on Computation Mechanics. ECCM.
EEVC Working Group 10 Report (1994): Proposals for methods to evaluate
pedestrian protection for passenger cars. November.
EEVC Working Group 17 Report (1998a): Improved test methods to evaluate
pedestrian protection afforded by passenger cars. December.
EEVC Working Group 17 Report (1998b): Pedestrian protection - synthesis of
experimental and simulation researches performed in France. INRETS. August
1998. EEVC WG 17 document 92.
Engin A.E. (1979a): Measurement of resistive torques in major human joints.
Aerospace Medical Research Laboratory, Report AMRL-TR-79-4.
Engin A.E. (1979b). Passive resistance torques about long bone axes of major human
joints. Aviation, Space and Environmental Medicine, 50-10, pp. 1052-1057.
Engin A.E. (1980): On the biomechanics of the shoulder complex. Journal of
Biomechanics, 13-7, pp. 575-590.
117
Release 7.6
Engin A.E. (1983). Dynamic modelling of human articulating joints. Mathematical
modelling, Vol. 4, pp. 117-141.
Engin A.E. (1984): On the damping properties of the shoulder complex. Journal of
Biomechanical Engineering, Vol. 106, pp. 360-362.
Engin A.E., Peindl R.D. (1987): On the biomechanics of human shoulder complex - I.
Kinematics for determination of the shoulder complex sinus. Journal of
Engin A.E., Chen S.M. (1988): On the biomechanics of the human hip complex in
vivo - I. Kinematics for determination of the maximal voluntary hip complex
sinus. Journal of Biomechanics, 21-10, pp. 785-796.
Engin A.E., Chen S.M. (1988): On the biomechanics of the human hip complex in
vivo - II. Passive resistive properties beyond the hip complex sinus. Journal of
Engin A.E., Chen S.M. (1989): A statistical investigation of the in vivo
biomechanical properties of the human shoulder complex. Mathematical Comput.
Modelling, 12-12, pp. 1569-1582.
Engin A.E., Tümer S.T. (1989): Three-dimensional kinematic modelling of the
human shoulder complex - Part I: Physical model and determination of joint
sinus cones. Journal of Biomechanical Engineering, Vol. 111, pp. 107-112.
Ewing C.L., and Thomas D.J. (1972): Human head and neck response to impact
acceleration. Monograph 21 USAARL 73-1, Naval Aerospace and Regional
Medical Centre, Pensacola.
Foust D.R., Chaffin D.B., Snyder R.G., and Baum J.K. (1973): Cervical range of
motion and dynamic response and strength of cervical muscles. In Proceedings of
the 17th Stapp Car Crash Conference, pp. 285–308. Society of Automotive
Engineers, SAE Paper No. 730975.
Frankel V.H., Nordin M. (1980): Basic biomechanics of the skeletal system.
Philidelphia, USA, Lea & Febiger.
GESAC, (2001): Biomechanical response requirements of the THOR NHTSA
advanced frontal dummy, Report no: GESAC-01-04.
Happee R., Haaster R. van, Michaelsen L., Hoffmann R. (1998): Optimisation of
vehicle passive safety for occupants with varying anthropometry. ESV
Conference, paper 98-S9-O-03.
Happee R., Ridella S., Nayef A., Morsink P., de Lange R., Bours R., van Hoof J.
(2000a): Mathematical human body models representing a mid size male and a
small female for frontal, lateral and rearward impact loading. IRCOBI
Conference.
118
Release 7.6
Hoof J. van, Happee R., Meijer R., Bours R. (2001): MADYMO FE human body
model for automotive impact conditions. JSAE Spring Convention, paper No
20015336.
Hoof J. van, Lange R. de, Wismans J. (2003): Improving Pedestrian Safety Using
Numerical Human Models. Stapp Car Crash journal. Vol. 47, pp. 401-436. SAE
Report No. 2003-22-0018.
Horst, van der M. (2002): Human head neck response in frontal, lateral and rear end
impact loading – modelling and validation. PhD Thesis, Eindhoven University of
Technology, ISBN 90-386-2843-9.
Irwin A.L., Walilko T.J., Cavanaugh J.M., Zhu Y, King A.I. (1993): Displacement
Responses of the Shoulder and Thorax in Lateral Sled Impacts. SAE 933124.
Irwin A.L., Mertz H.J., Biomechanical basis for the CRABI and Hybrid III child
dummies. SAE 973317.
Ishikawa, H., Kajzer, J., Schroeder, G. (1993): Computer Simulation of Impact
Response of the Human Body in Car-Pedestrian Accidents. Proc. 37th Stapp Car
Crash Conference. SAE Paper No. 933129.
ISO Technical Report 9790 (1997): Road vehicles – Anthropomorphic side impact
dummy- lateral impact response requirements to assess the biofidelity of the
dummy, ISO/TC22/SC12/WG5 (Anthropometric Test Devices), Document N455
– Revision 4.
Jager, M.K.J. de (1996): Mathematical head-neck models for acceleration impacts.
PhD thesis, Eindhoven University of Technology, Eindhoven, The Netherlands.
Kajzer J., Cavallero C., Ghanouchi S., Bonnoit J., Ghorbel A. (1990): Response of the
Knee Joint in Lateral Impact: Effect of Shearing Loads: IRCOBI Conference
Proceedings, pp. 293-304.
Kajzer J., Cavallero C., Bonnoit J., Morjane A., Ghanouchi S. (1993): Response of
the Knee Joint in Lateral Impact: Effect of Bending Moment. IRCOBI
Conference Proceedings, pp. 105-116.
Kajzer J., Schroeder G., Ishikawa H., Matsui Y, Bosch U. (1997): Shearing and
bending effects at the knee at high speed lateral loading. Stapp Car Crash
Kapandji I.A. (1974): The Physiology of the Joints, Volume 3: The Trunk and the
Vertebral Column. Churchill Livingstone, Edinburg, 2nd edition.
Kent R.,Stacey S., Kindig M., Forman J. Woods W. Rouhana S.W., Higuchi K., Tanji
H., Lawrence S. St., Arbogast K.B. (2006): Biomechanical Response of the
Pediatric Abdomen, Part 1: Development of an Experimental Model and
119
Release 7.6
Quantification of Structural Response to Dynamic Belt Loading, Stapp Car Crash
Journal 50.
Keshner E.A. (2003): Head-Trunk Coordination During Linear Anterior-Posterior
Translations, Journal of Neurophysiology 89:1891-1901.
Koppens W.P. (1988): The dynamics of systems of flexible bodies. PhD thesis,
Eindhoven University of Technology, The Netherlands.
Kramer M., Burow K., Heger A. (1973): Fracture mechanism of lower legs under
impact load. Proc. 17th Stapp Car Crash Conference. SAE Paper No. 730966.
Kress T.A., Snider J.N., Porta D.J., Fuller P.M., Wasserman J.F., Tucker G.V. (1993):
Human femur response to impact loading. Proc. 18th IRCOBI Conference
Proceedings.
Kroell C.K., Schneider D.C. and Nahum M. (1971): Impact tolerance and response of
the human thorax. Proceedings of the 15th Stapp Car Crash Conference, SAEpaper No 710851.
Kroell C.K., Schneider D.C. and Nahum M. (1974): Impact tolerance and response of
the human thorax II. Proceedings of the 18th Stapp Car Crash Conference, SAEpaper No 741187.
Kroell C.K. (1994): Thoracic Response to blunt frontal loading. In: Biomechanics of
impact injury and injury tolerances of the thorax-shoulder complex, Edited by
Backaitis S.H., published by Society of Automotive Engineers, Inc., pp. 51-80.
Kroell C.K. (1976) Thoracic response to blunt frontal loading in The Human Thorax,
Society of Automotive Engineers publication P-67, pp 49-77, 1976. Reprinted in
Biomechanics of Impact Injury and Injury Tolerances of the Thorax-Shoulder
Complex, Backaitis (edited), Society of Automotive Engineers publication PT45, pp 51-79, 1994.
Kroonenberg A. van den, Thunnissen J., Wismans J. (1997): A human model for low
severity rear-impacts. IRCOBI Conference.
Kroonenberg A. van den, Philippens M., Cappon H., Wismans J. (1998): Human
head-neck respinse during low-speed rear end impacts. Stapp Car Crash
Lange R. de, Rooij L. van, Mooi H., Wismans, J. (2005): Objective biofidelity rating
of a numerical human model in frontal to lateral impact. Stapp Car Crash
Conference, SAE 2005-22-0020.
Liu X. (2003): Mathematical Simulation of Vehicle-Pedestrian Collisions. PhD thesis,
Chalmers University of Technology, Sweden.
120
Release 7.6
Lizee E., Robin S., Song E., Bertholon N., Le Coz J., Besnault B., Lavaste F. (1998):
Development of a 3D finite element model of the human body. Stapp Car Crash
Ma D., Obergefell A., Rizer A. (1995): Development of human articulating joint
model parameters for crash dynamics simulations. Stapp Car Crash Conference,
SAE 952726.
Markolf K.L. (1972): Deformation of the thoracolumbar intervertebral joints in
response to external loads. Journal of Bone and Joint Surgery, Vol. 54-A, No. 3,
pp. 511-533.
Markolf K.L. et al.. (1976): Stiffness and laxity of the knee. The contributions of the
supporting structures. Journal of Bone and Joint Surgery (AM). vol 58-A. No. 5.
Meijer R., Parenteau C., Hoof J. van, Gopal M. (2003): Validation of a MADYMO
Mathematical Human Body Model with Detailed Neck in Low Speed Lateral
Impacts. IRCOBI Conference, Lisbon.
Meijer R., Rodarius C., Adamec J., Nunen van E., Rooij van L. (2008): A first Step in
Computer Modelling of the Active Human Response in a Far-Side Impact,
International Journal of Crashworthiness, Vol 13, pp. 643–652.
Meijer, R., Hassel van, E., Broos, J., Elrofai, H., Rooij van, L., Hooijdonk van, P.
(2012): Development of an active multi-body human model that predicts active
and passive human behaviour. IRCOBI Conference, Dublin.
Meyer E., Bonnoit J. (1994): Le choc lateral sur l’épaule: mise en place d’un
protocole expérimental en sollicitation dynamique. Mémoire de DEA,
Laboratoire de bioméchanique appliquée, faculté de Marseille.
Miller M.Z., Mosher S.E. (1989): Test configuration and data aquisition system for
the investigation of human response to varied +gz impact duration and amplitude
(HGZ study) test program, DynCorp Scientific Support Division, WrightPatterson AFB, Ohio.
Moroney S., Schultz A., Miller J., Andersson G. (1988): Load-displacement
properties of lower cervical spine motion segments. Journal of Biomechancis, 21,
pp. 769-779.
Muggenthaler H., Praxl N., Adamec J., Von Merten K., Schönpflug M. et al (2005):
The effects of muscle activity on human kinematics and muscle response
characteristics – Volunteer tests for the validation of active human models, SAE
Paper 2006-01-2370, Digital Human Modelling Conference paper 06DHM-8.
Nahum M., Gadd C.W., Schneider D.C. and Kroell C.K. (1970): Deflection of the
human thorax under sternal impact. Proceedings of the International Automobile
Safety Conference, Detroit, SAE-paper No 700400.
121
Release 7.6
Nahum M., Schneider D.C. and Kroell C.K. (1975): Cadaver skeletal response to
blunt thoracic impact. Proceedings of the 19th Stapp Car Crash Conference,
SAE-paper No 751150.
Neathery R. (1974): Analysis of chest impact response data and scaled performance
recommendations. Stapp Car Crash Conference, SAE paper 741188, 1974.
Nemirovsky N. and Rooij van L. (2010): A New Methodology for Biofidelic HeadNeck Postural Control, IRCOBI Conference.
Nusholtz, G., and Kaiker, P. (1994): Abdominal Response to Steering Wheel
Loading. Proceedings of the 14th International Conference on Experimental
Safety Vehicles.
Nyquist H.B., Cheng R., El-Bohy A.A.R., King A.I. (1985): Tibia bending: strength
and response. Stapp Car Crash Conference, SAE paper 851728.
Ono K., Inami S., Kaneoka K., Gotou T., Kisanuki Y., Sakuma S., Miki K (1999):
Relationship between localized spine deformation and cervical vertebral motions
for low speed rear impacts using human volunteers. IRCOBI Conference.
Ouyang J., Zhu Q., Zhao W., Xu Y.,Chen W., Zhong S. (2005): Biomechanical
Assessment of the Pediatric Cervical Spine Under Bending and Tensile Loading,
Spine Volume 30, Number 24, pp E716–E723.
Ouyang J., Zhao W., Xu Y., Chen W., Zhong S. (2006): Thoracic Impact Testing of
Pediatric Cadaveric Subjects, The Journal of TRAUMA_ Injury, Infection, and
Critical Care, 61:1492–1500.
Panjabi M.M., Duranceau J., Goel V., Oxland T., and Takata. K. (1991a): Cervical
human vertebrae: Quantitative three-dimensional anatomy of middle and lower
regions. Spine, 16, pp. 861-869.
Panjabi M.M., Takata K., Goel V., Frederico D., Oxland T., Duranceau J., and Krag.
M. (1991b): Thoracic human vertebrae: quantitative three-dimensional anatomy.
Spine, 16, pp. 888-901.
Panjabi, M.M., Oxland T.R., Yamamoto I., Crisco J.J. (1994): Mechanical behaviour
of the human lumbar and lumbosacral as shown by three-dimensional loaddisplacement curves. Journal of Bone and Joint Surgery, Vol. 76-A, No. 3.
Parenteau, C.S. (1996): Foot-Ankle Joints Responses. Epidemiology, Biomechanics
and Mathematical Modeling. PhD Thesis, Chalmers University of Technology.
Gothenburg.
Phillipens, M. Cappon, H., van Ratingen, M. (2004) Human volunteer head-T1
response for oblique impact conditions, Proceedings of the International IRCOBI
Conference on the Biomechnics of Impact, Graz, Austria.
122
Release 7.6
Pintar F.A., Myklebust J.B., Sances Jr. A., and Yoganandan N. (1986a):
Biomechanical properties of the human intervertebral disk in tension. In:
Advances in Bioengineering, pp. 38-39. American Society of Mechanical
Engineers.
Pintar F.A. (1986b): The Biomechanics of Spinal Elements. PhD thesis, Marquette
University.
Piziali R.L., Rastegar J.C. (1977): Measurement of the nonlinear, coupled stiffnerss
characteristics of the human knee. Journal of Biomechanics, Vol. 10, pp. 45-51.
Platzer W. (1989): Pernkopf Anatomy. Atlas of Topographic and Applied Human
Anatomy, volume 1: Head and Neck. Urban & Schwarzenberg Baltimore–
Munich, 3rd edition.
Prasad P. & King A.I. (1974): An experimentally validated dynamic model of the
spine. Journal of Applied Mechanics, pp. 546-550.
Quiring D.P. (1947): The Head, Neck, and Trunk. Muslces and Motor Points. Lea &
Febiger, Philadelphia.
RAMSIS, RAMSIS Manual version 3.1, Tecmath Gmbh, Kaiserlautern, Germany,
1997.
Reid S.E., Raviv G., and Reid Jr. S.E. (1981): Jr. Neck muscle resistance to head
impact. Aviation, Space, and Environmental Medicine, pp. 78–84.
Robin S. (2001): HUMOS: Human model for safety – a joint effort towards the
development of refined human-like car occupant models. 17th International
Technical Conference on the Enhanced Safety of Vehicles, paper 297.
Rodmell C., Lawrence G.J.L. (1998): Further pedestrian accident reconstructions with
the upper legform impactor. EEVC WG17 document 113 revision 1.
Rooij L. van, Elrofai H., Philippens M.M., Daanen H.A. (2013): Volunteer
kinematics and reaction in lateral emergency maneuver tests. Stapp Car Crash
journal. Vol. 57, pp. 313-342. SAE Report No. 2013-13.
Schoeneburg R, Baumann K.H., Fehring M (2011): The efficiency of PRE-SAFE
systems in pre-braked frontal collision situation, paper number 11-0207, ESV
Conference.
Schueler F., Glasson E. (1998): Analysis of the pedestrian to bonnet leading edge
impact, Evaluation of the impact energy. ECIA/CSA/98-69/EG. WG17/Doc86,
France.
Schultz, A.B., Warwick D.N., Berkson M.H., Nachemson A.L. (1979): Mechanical
properties of human lumbar spine motion segments - Part 1: Responses in
123
Release 7.6
flexion, extension, lateral bending, and torsion. Journal of Biomechanical
Engineering, Vol. 101, pp. 46-52.
Seireg A. and Arvikar R.J. (1989): Biomechanical Analysis of the Muscoloskeletal
Structure for Medicine and Sports. Hemisphere Publishing Corporation, New
York.
Schneider L.W., Foust D.R., Bowman B.M., Snyder R.G., Chaffin D.B., Abdelnour
T.A., and Baum J.K. (1975): Biomechanical properties of the human neck in
lateral flexion. In Proceedings of the 19th Stapp Car Crash Conference, pages
455–485. Society of Automotive Engineers, 1975. SAE Paper No. 751156.
Speyer H., Seidl A. (1997): RAMSIS - A New CAD Tool for Ergonomic Analysis of
Vehicles Developed for the German Automotive Industry. SAE paper 970088.
Talantikite Y., Bouquet R., Ramet M., Guillemot H., Robin S., Voiglio E. (1998):
Human thorax behaviour for side impact - Influence of impact mass and
velocities. ESV paper 98-S7-O-03.
Tennyson S.A., Mital N.K., and King A.I. (1977): Electromyographic signals of the
spinal musculature during +Gz impact acceleration. Orthopedic Clinics of North
America, Vol. 8, pp. 97–119.
Thunnissen J.G.M., Happee R., Eummelen P., Beusenberg M.C. (1994): Scaling of
adult to child responses applied to the thorax. IRCOBI conference.
Twisk D., Beusenberg M. (1993): Anthropometry of children for dummy design.
ECOSA Product Safety Conference, Amsterdam.
Verver M.M., Hoof J. van, Oomens C.W.J., Wouw N. van de, Wismans J.S.H.M.
(2003): Estimation of spinal loading in vertical vibrations by numerical
simulation. Clinical Biomechanics, Vol. 18, No. 9, pp. 800-811.
Verver M.M. (2004): Numerical tools for comfort analyses of automotive seating.
PhD thesis, Eindhoven University of Technology, ISBN: 90-386-2855-2, 2004,
http://yp.wtb.tue.nl/pdfs/4005.pdf.
Viano C.V. (1989): Biomechanical responses and injuries in blunt lateral impact.
Proceedings of the 33th Stapp Car Crash Conference, SAE-paper No 892432, pp.
113-142.
Walker P.S., Hajek G.V. (1972): The load bearing area in the knee joint. Journal of
Biomechanics, Vol. 5, pp. 581-589.
Winters J.M. and Peles J.D. (1990): Neck muscle activity and 3-D head kinematics
during quasi-static and dynamic tracking movements. In: J.M. Winters and S.LY. Woo, editors, Multiple Muscle Systems: Biomechanics and Movement
Organization, pp. 461-480. Springer-Verlag.
124
Release 7.6
Yamada H. (1973): Strength of biological materials (edited by Evans F.C.). Williams
and Wilkins, Baltimore Maryland.
Yamamoto, I., Panjabi M.M., Crisco T., Oxland T. (1989): Three-dimensional
movements of the whole lumbar spine and lumbosacral joint. Spine, Vol. 14, No.
11.
Yang J., Kajzer J., Cavallero C., Bonnoit J. (1995): Computer Simulation of Shearing
and Bending Response of the Knee Joint to a Lateral Impact. Proceedings of the
39th Stapp Car Crash Conference, pp. 251-264.
Yang J.K., Lövsund P. (1997): Development and validation of a human body
mathematical model for simulation of car-pedestrian impacts. IRCOBI
Conference.
Yang J.K., Lövsund, P., J., Cavallero C., Bonnoit J. (2000): A Human-Body 3D
Mathematical Model for Simulation of Car-Pedestrian Impacts. International
Journal of Crash Prevention and Injury Control, Vol. 2(2), pp. 131-149.
Yoganandan N., Pintar F.A., and Stemper B.D. (2001): Single rear impact produces
lower cervical spine soft tissue injuries. In: International IRCOBI Conference on
the Biomechanics of Impacts, pp. 201-211.
125

MADYMO Human Body Models Manual Release 7.6 April 2015

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