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femfat
Winter Edition 2007 - No. 13 Although the editor's meeting wanted to greet you with a ghostly halloween pumpkin - this is, after all, the 13th issue of the Newsletter - we would like to use this contemplative season of advent to pause and think instead, especially now that we can distribute the brand new Version 4.7, well conceived and tested - which fills us with particular pride. In this context we would like to immediately lead over to a retrospective of an Excellent 2007 for FEMFAT We are delighted with FEMFAT's success around the globe, which was crowned by the Technical Innovation Prize of the State of Lower Austria, presented to Dr. Christian Gaier, Head of FEMFAT Development, on October 23, 2007 in St. Pölten. The technically high-quality presentations at the FEMFAT User Meeting, together with the FEMFAT 4.7 preview, ensured that the orders for FEMFAT came streaming in, even during the "summer break". We are ver y pleased with this development. Karl Ritter von Gega Prize 2007, presented by Ernest Gabmann (Lower Austria State Economic Council) and Sonja Zwazl (WKNO President) to Dr. Christian Gaier (Head of FEMFAT Development) and Dipl.-Ing. Helmut Antensteiner (Head of Project Controlling) for innovative analysis concepts in FEMFAT Contents: FEMFAT Retrospective _________ 1 Evaluation of short-fiber-reinforced plastics with FEMFAT MAX 4.7 ____ 2 FAQs: •How can FEMFAT process my _ ABAQUS odb files? __________ 3 •How should load case numbers be defined in TransMAX? _____ 3 • How impor tant is the time in- _ formation in HEAT Sehitoglu? _ 3 Training/Events _______________ Tips _________________________ Event Calendar ________________ Publisher's Information ________ 4 4 4 4 Visit our website: www.femfat.com Despite extensive development work - which manifests itself primarily in a reduction in computation times, and more user-friendly operation and visualization - and an increase in payroll costs, FEMFAT module prices have not increased in the last five years. This has only been possible thanks to increased deployment of FEMFAT. It is also remarkable that FEMFAT was able to increase its standing outside of the dominating vehicle industry. The possible fields of application for FEMFAT are by no means exhausted and we are already working on fur ther methods, which we will make available to you in the coming years, tailor-made and verified. Today we thank you for your trust in FEMFAT and our team and wish you a Merry Christmas and a Happy New Year. your FEMFAT-Team Japan TEC Show The DMSK 2007 was held from October 1 to 3 in the INTEX (Int. Exhibition Center) in Osaka (30,000 delegates). Our young and dynamic team from the MAGNA Tokyo Of fice (Noriyuki Muramatsu, Kazumasu Kato and Terue Goto) organized par ticipation in this technical exhibition for the second time in order to introduce our software products to the interested Japanese public. Numerous manufacturer's of machine tools and household products also showed an interest in FEMFAT. Great interest was also noted in the new analysis options available for plastics. During this 3 day event approximately 80 consultations were held, representing an important step for Japanese industry. To me, the Japanese are highly interested in, and open to, anything new, in contrast to many central Europeans. An exhibition booth at the DMSK 2008 is already booked; before this we are also represented at the JSAE in May 2008. Dear Tokyo team – keep up the good work – and many thanks for your hard work. Helmut Dannbauer FEMFATNEWSLETTER Winter Edition 2007 - No. 13 Evaluation of short-fiber-reinforced plastics with FEMFAT MAX 4.7 In FEMFAT MAX (BASIC is on its way) it is now possible to evaluate components made of short-fiber-reinforced plastics, taking the fiber orientation and fiber distribution into special consideration (FEMFAT "POLY"). Injection molding simulation results can be processed from MOLDFLOW directly within FEMFAT for this purpose (Fig. 1). MOLDFLOW injection die cast simulation Abaqus interface for MOLDFLOW Abaqus stress analysis These material parameters can be taken from tests on unnotched flat samples, carried out on injection molded slabs parallel and perpendicular to the fiber orientation (Fig. 3). If not all data for the transverse fiber direction are available, FEMFAT partially utilizes the data from the parallel samples. FEMFAT fatigue life prediction Fig. 1: Data flow from the injection molding simulation through the entity stress analysis to the damage forecast. The injection molding simulation file job-name-fiber-tensor.xm1 contains the fiber orientation tensor for every solid element (generally a linear tetrahedron), from which the three principal orthotropy directions and the fiber components λi for each principal direction can be computed (Fig. 2). In the next step, this information is transferred ("mapped") from the FEM mesh of the injection molding simulation to the FEM mesh of the strength analysis . Fig. 4 Material data perpendicular to fiber Fig. 2: left: Example of random fiber distribution; right: Example of highly pronounced fiber orientation; Since the middle of this year MOLDFLOW has made available a software application to transfer data to ABAQUS. In FEMFAT, an orientation tensor is applied to nodes, which is determined by averaging the tensors at the neighboring elements for each component. In addition, static and cyclic material parameters for tensile and compressive loads parallel and perpendicular to the fiber orientation are required for a damage prediction using FEMFAT (Fig. 4). Fig. 5: "Fiber orientation" influence If no cyclic material parameters are available (S/N curve, cyclic stress-strain curves), it may be possible to roughly estimate them from static parameters (tensile strength). The FEMFAT team will be happy to assist. With regard to the theoretical aspects, it should be noted that it was necessary to expand the critical cutting plane method. Due to the orthotropic strength distribution, failure can also occur in a plane subject to minor loading, in contrast to isotropic materials. For practical application please watch out that the check box for the new "Fiber orientation" influence must be activated (Fig. 5). Nothing now stands in the way of an analysis using "FEMFAT POLY", because no separate module with a corresponding license is required. Fig. 3: Sampling from injection molded slabs. 2 Christian Gaier FEMFATNEWSLETTER Winter Edition 2007 - No. 13 FAQs How can FEMFAT process my ABAQUS odb files? You may remember from older Newsletters that the so-called odb libraries, which functions as a translator between the two software products, are required to import ABAQUS odb files into FEMFAT. The definition also applies to ChannelMAX, in analogy to TransMAX. In addition, the user must note that intermediate increments can be defined using load case numbers in the ABAQUS (.fil and .odb) interface. In this case the default setting must be deactivated (see Fig. 2). The current odb libraries (6.7.x) are automatically installed when installing the new FEMFAT 4.7 Version. That is, the user must now keep this up-to-date, because it is possible for the libraries to be modified in the course of an existing version of FEMFAT. This depends entirely on the new ABAQUS versions released in the interim. These libraries are available as compressed files for a variety of hardware platforms on our homepage at www.femfat.com (registration necessary). It is possible to download "odb6.6.x" separately in the final column, as shown in Fig. 1. It should be noted that these libraries are only downwards compatible. For example, this means that odb files created using ABAQUS 6.6.x can also be imported into FEMFAT with the aid of 6.7.x odb libraries. Fig.2 As of FEMFAT Version 4.7 it is also possible to have the result file scanned (right mouse button in the "Stress data" input box); the user then has a comfortable option for selecting via the existing load cases. Eberhard Dutzler How important is the time information in HEAT Sehitoglu? Analysis of damage or fatigue life from load-time series' (LTS) was previously performed in FEMFAT MAX regardless of the elapsed time. Strains were not utilized in either ChannelMAX or TransMAX due to the approach via local stresses and the influence parameter concept. This changed with the implementation of the damage hypothesis according to Prof. Huseyin Sehitoglu in TransMAX. Sehitoglu divides the total damage for thermomechanical fatigue into 3 terms: Dmech … the mechanical damage component according to COFFIN/MANSON Dox …… the oxidation damage/ambient damage component Dcreep … the creep damage component Dtotal = Dmech + Dox + Dcreep Fig. 1: Download area at www.femfat.com It is recommended to always install the odb libraries corresponding to the ABAQUS versions to be employed, otherwise the odb files are "upgraded" and increase in size. Speaking of installation – the uncompressed odb libraries belong in the FEMFAT installation folder, more precisely in the odb folder created there automatically during installation. (Example:....\femfat47\platforms\winnt_51_i686_32bit\odb\). Marco Fahrner In the oxidation damage according to BOISMIER, KADIOGLU and ox . SEHITOGLU the oxidation phase Φ and the strain rate (ε) are very highly dependent on the strain history over time. Creep damage is most prominent for an in-phase TMF load (mechanical loads enhance thermal strain) and is integrated over the cycle time. This naturally implies that damage is time-dependent. How should load case numbers be defined in TransMAX? This is different depending on the file format: File Format I-deas (.unv) Nastran Punch (.pch) Ansys Presol (.lis) Patran Result (.rpt) Medina (.bof) Pro/Mechanica (.*s*) Nastran (.op2) Abaqus (.odb) Cosmos/M (.out) Abaqus (.fil) Ansys (.rst) LSDyna (.d3plot) Marc (.t16) Permas (.post) Load case number definition Specify load case number Specify load case number Only one load case possible in result file Only one load case possible in result file Load cases always begin with 1 Only one load case possible in result file Load cases always begin with 1 Load cases always begin with 1 Only one load case possible in result file Load cases always begin with 1 Load cases always begin with 1 Load cases always begin with 1 Load cases always begin with 1 Load cases always begin with 1 The time information (unit: seconds) can be defined in a number of ways. Either the step time from the stress, strain or temperature results can be used (which makes more uncommon step time definitions necessary) or a separate table is imported as a text file. This can be performed on the "Time information" tab. Up until Version 4.6 the time integration for oxidation and creep damage was carried out relatively simply. Different resolutions when specifiying a heating process across various states led to different results. Time integration has been greatly improved as of Version 4.7. It is now sufficient to specify start and end times, the temperature history for this period is then implied as linear. This leads to a precise result despite only a small amount of data being necessary and a fast analysis. Axel Werkhausen 3 FEMFATNEWSLETTER Winter Edition 2007 - No. 13 Training - Dates 2008 Fatigue life/Damage and safety factors for simple loads, comprehensive FE-interfaces and material database Engineering Center Steyr, St. Valentin 6.-7. February 16.-17. April 3.-4. June 6.-7. August 15.-16. October 3.-4. December Engineering Center Troy, Detroit 29. February 18. June 11. September Prices (excl. VAT): per delegate for each further delegate from the same company University/Research group Euro 770.00 Euro 610.00 Euro 300.00 Including 2 month FEMFAT evaluation license Information: [email protected] 3D-postprocessor and WELD definition Multiaxial fatigue Welded structures *** TIPS *** TIPS *** TIPS *** TIPS *** TIPS *** TIPS *** TIPS *** TIPS *** Spot-joined structures FEMFAT VISUALIZER price increase As previously announced in Newsletter 10, we have decided to increase the price of the VISUALIZER for 2008. The module has been greatly expanded in the past (e.g. weld definitions) and this is the first increase for several years. Fast movers can still buy VISUALIZER at its original price until the end of 2007. A 20% increase will take effect as of January 1, 2008. Thermo-mechanical fatigue Always use a current version of FEMFAT! PLAST We recommend always to use the FEMFAT versions currently made available on our homepage www.femfat.com. Of course it is not always easy to keep up with the latest software releases, especially in large companies due to the longer IT order channels, but it is enormously important. Bugs, which creep into every software product whether we like it or not, are eliminated in maintenance versions and interfaces brought up-to-date. For new "Major Releases" such as the current version 4.7 you can profit from module extensions, new methods and improved user interfaces. We realize that moving to a new version involves a certain amount of work; however, the advantages far outweigh this disadvantage. A compact description of all improvements is available in the release notes on the homepage www.femfat.com. Axel Werkhausen Local plasticity BREAK Static safety factors STRAIN Virtual strain gage/ Measured strain damage FEDIS Sub-modeling Event Calendar Engine dynamics/Acoustics simulation Analysis & preparation of data Impressum: Engineering Center Steyr GmbH & Co KG Steyrer Strasse 32, A-4300 St. Valentin Tel: +43 7435 501 303, Fax: +43 7435 501 300 [email protected] 4 SAE India Marcus Evans Conference: “IT-supported PDP” FEMFAT Road Show 8. Stuttgarter Symposium Assurance of System Reliability, DVM Workgroup SAE World Congress 2008 2nd Fatigue Symposium DVM Conference 2008 FEMFAT Road Show HdT Seminar “Material Models for Finite Elements” Commercial Vehicle Workshop Graz SF2M Conference “Fatigue and Plasticity” SCT 2008 Symposium on Structural Durability/LBF FEMFAT Japanese User Meeting New Delhi Stuttgart Munich Stuttgart Koblenz Detroit Leoben Berlin Zurich Munich Graz Paris Wiesbaden Darmstadt Nagoya 09.-11.01.2008 30.-31.01.2008 06.03.2008 11.-12.03.2008 02.-03.04.2008 14.-18.04.2008 23-.24.04.2008 23.-25.04.2008 29.04.2008 06.-07.05.2008 16.05.2008 20.-22.05.2008 01.-05.06.2008 05.-06.06.2008 20.06.2008