docMBS Simulation Techniques to Determine Spatial Load
download 
Report Transcription
MBS Simulation Techniques to Determine Spatial Load
SIMPACK User Meeting 2014 MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches Gerald Ochse University Kassel, IAF/MT Richard Schönen IST GmbH Aachen Carsten Träbing, Volker Ploetz Schaeffler Technologies GmbH & Co. KG Content • Problem Statement, Goal, Implementation • Basis • Contact Situation • Force and Friction Models • Freewheel Clutch • Simulation • Experiment • Comparison • Summary MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 2 Problem Statement Initial Situation: • Software tools for the dynamic simulation of multi body systems (MBS) are available and well established • Models for internal contact and transfer of loads may be: • Either insufficient in terms of modeling contact mechanics and/or • Time-consuming in their application Need for: • Proper modeling of contact physics • Consideration of global and local stiffness effects • Analysis of components in complete systems in full interaction MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 3 Goals & Realization Goals: • To establish time efficient methods and algorithms for contacts in MBS systems • To make available different physical models for frictional forces • To fully implement in MBS simulation • To support ease of use with a Graphical User Interface Implementation: • • • • Adequate contact algorithms were cast in external Fortran routines Integration in commercial MBS-Program by standardized interfaces Simple contact model for validation vs. existing internal routines Extension of contact and friction models to consider effects of • Slip and sum velocities • Lubricant parameters • Surface roughness MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 4 Contact Situation Approach and Overlap of two Rigid Bodies • are defined by • Position • Velocity • Geometry MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 5 Force Models of the UFEL Force Models: • Spring-Damper • DIN ISO 281 • Hertz elliptical • Wijnant (extension Hertz by lubrication) Spring-Damper: • Standard Contact • Simpack Force 18 g(L) d WIJ 2 1 R x ɶ 3 4 ⋅ f (L) ⋅ ⋅M ⋅ ( F ⋅ R ⋅ ε ) ⋅ ( E '⋅ π ) 3 Ry = 1 ( 6 ⋅ κ ) 3 ⋅ K ⋅ Vhyd e δ FFD = s ⋅ c x − d ⋅ v s 1 0.8 0.9 ⋅B δ ⋅10 F281 = 3.97 5 δ ⋅ 2R ⋅ ε K FHZ = 2 3R 2 κε 3 E' ⋅ π 3 2 q(L) R ⋅ δ δWIJ = 1 − p(L) ⋅ x ⋅ M HZ R y MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 6 Friction Models of the UFEL µ stat Friction Models: • constant (static/dynamic) µdyn • Drozdov / Gavrikov • O‘Donoghue / Cameron vvgleit vtrans vtrans slide • Misharin 0.25 0.25 1 Raa R ⋅⋅ • Benedict & Kelly µ DRG = 0.63e − 6 0.8 ⋅ Vslide ⋅ ν + V ⋅ Φ (p ; ν ) + 13.4 0.63e − 6 ν ) + 13.4 Σ cs m gleit m cs cs • ISO / TC60 Φ = 0.47 − 0.13 ⋅10−4 ⋅ p m − 0.4 ⋅10−3 ⋅ ν cS • external DLL Parameters : R a ,S surface parameter pm hertzian pressure W' specific line load ν, η viscosity V surface velocity R contact radius 0, 6 ⋅ µ ODC = 1 8 S + 22 35 1 3 1 6 η0 ⋅ Vslide ⋅ VΣ ⋅ R µ MIS = 0,325 ⋅ ( Vslide ⋅ VΣ ⋅ ν k ) µ BUK µ TC6 1 2 W '⋅ S = 0,12 ⋅ R ⋅ V ⋅ η Σ 0 0,25 −0,25 3,17 ⋅ (10 )8 ⋅ W ' 50 = 0, 0127 ⋅ ⋅ log10 ⋅ η ⋅ V ⋅ V 2 50 − S 0 slide Σ MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 7 Examples of Freewheel-Clutches Feeder-Unit Overrunning clutch Return stop • material • starter motor • elevators • conveyor band Firmenschrift Ringspann GmbH, Bad Homburg, 2012 MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 8 Idling and Switching of a Freewheel Clutch Idling Switching / Locking ωouter ωouter ωinner ωinner MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 9 MBS Freewheel: Elements, Force Coupling, DOF Subsystem Force Coupling Z Contact Sprag / Outer Race Sprag Contact Sprag / Cage Torque-Momentum Sprag / Cage Contact Sprag / Inner Race Outer Race Y Cage X DOF Inner Race rot. rot. Main Model trs. y rot. trs. z MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 11 MBS Freewheel: Elements, Force Coupling, DOF • Single / multi area contact • Force coupling • 3D load distribution • Eccentricity, misalignment • Substituted stiffness of outer race Contact Sprag / Outer Race Z Contact Sprag / Cage Torque-Momentum Sprag / Cage Contact Sprag / Inner Race Sprag Outer Race Y Cage Inner Race rot. rot. X trs. y rot. trs. z MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 12 UFEL - GUI • • • • Create new or Modify existing contact Contact Marker From & To are based on Marker 96 Data Input MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 13 UFEL Disc Model Disc Model • Discretisation of the contact in direction of width • Gap and overlapping at skew position and crowning b R b ϕ ϕ gap gap and overlapping overlapping MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 14 MBS: Normal Force & Pressure Distribution Sprag Width [mm] Angle 3 Switch Cycles Contact Force [kN] Sprag Width [mm] Skewing of the Outer Race 3 Switch Cycles Angle Angle Angle Sprag Width [mm] Intended Distribution 3 Switch Cycles Crowned Sprag 3 Switch Cycles MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 15 Variation of Stiffness and Clearance c2 = 2.5e8 ⋅ mN c2 = 0.5 ⋅ c1 Clearance : 1 100 ⋅ mm c3 = 10 ⋅ c1 MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 16 Experimental Work Frontside Backside • Freewheel: o Sprags with strain gauges o at marked positions MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 17 Experimental Work • Sprag with Strain Gauges at both sides MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 18 Experimental Work • Calibration Unit • Continuous Force up to 10 kN Sprag with strain gauge Calibration Unit MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 19 Flange Modification in Simulation & Experiment Asymmetric Load Distribution • Reduced outer diameter 78 mm 70 mm MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 20 Flange Modification in Simulation & Experiment Asymmetric Load Distribution • Reduced outer diameter • Stiffening with a ring (SR) in the positions front, middle, rear • Configuration for test rig and FE-Analysis • Calculation of the substituted stiffness 70 mm, SR front 70 mm, SR middle 70 mm, SR back Contact zone sprag / flange MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 21 Distributed Load in the Experiment Asymmetric Load Distribution • Force measurement with strain gauges (SG) at the sprag • Normal-Force in kN 6,52 5,05 5,19 SG back 6,12 SG front 5,96 5,75 70 mm, SR front 70 mm, SR middle 70 mm, SR back MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 22 Freewheel with Lineload in the FE-Simulation MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 23 Displacement Results from FE-Analysis Displacement at 10 kN line load, variation of outer flange diameter and place of the stiffning ring (SR) Displacement in mm SR back SR middle SR front without SR front middle back Width in mm MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 24 Comparison of Experiment and Simulation Asymmetric Load Distribution Stiffening ring in position front 3 contacts and substituded stiffness for flange Good agreement Difference 3-5% Experiment Simulation back middle front • • • • Force in N 3 contacts hinten back mittig middle vorne front MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 25 Summary • Efficient methods and algorithms for modeling contact in MBS simulation with different model depths have been implemented and validated • 4 force models, 6 friction models and external DLL • Parameters influencing the contact behaviour include • Position, velocity, surface velocity, crowning, lubrication • Width discretisation of compliances is considered by disc model (direct stiffness) • Implementation into commercial MBS-Program Simpack was successfully validated • Marginal increase of calculation time • ca. 8% with 200 discs • 1-2% with Wijnant instead of Hertz • Additional Results • Postprocessing in Simpack • Data output in ASCII-Files (3D-representation, postprocessing) MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 26 Thanks to AiF Schaeffler Technologies GmbH & Co. KG FVA IST Simpack AK-Freiläufe MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 27 Contact Universität Kassel / University Kassel Institut für Antriebs- und Fahrzeugtechnik / Institute for Powertrain an Automotive Engineering Maschinenelemente und Tribologie / Chair for Machine Elements and Tribology Prof. Dr.-Ing. Adrian Rienäcker Mönchebergstr. 3 34125 Kassel T: +49 (0)561 804-2774 F: +49 (0)561 804-3727 [email protected] MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches 28
