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8th European LS-DYNA Conference

3-Dimensional Forming of Thick Plates - A Comparison of Deep Drawing and an Approach of Rolling and Bending within a Single Process
Manuel Bojahr, Hannes Prommer, Ralf Tschullik, Patrick Kaeding - University of Rostock
A variety of industries require certain 3-dimensional formed thick plates, for example in shipbuilding for shell plates. Nowadays the production of curved ship plates is mainly based on the experience of the worker and is performed manually. The results are good and sufficient for the heretofore use in industry, taking into account that the number of curved plates with the same geometry is quite small. Moreover thick plates with a ...
A constitutive equation for the aging of elastomer and application to dummy impact programs
William W. Feng, John O. Hallquist, Christoph Maurath - Livermore Software Technology Corp
A constitutive equation for chronorheologically simple materials that describes the aging and viscoelastic behaviors of elastomer is presented. A simulated numerical uniaxial relaxation test of a material at various aging stages has been performed. The simulated experimental results demonstrate the chronorheological effect and are used further to determine the material property functions in the constitutive equation. A test of an elastomer ...
A constitutive model for thermoplastics with some applications
Arild Holm Clausen, Mario Polanco-Loria1, Torodd Berstad and Odd Sture Hopperstad - Norwegian University of Science and Technology
A constitutive model for thermoplastics is outlined in this paper. The model consists of two parts: A hyperelastic-viscoplastic response due to intermolecular resistance denoted Part A, and an entropic hyperelastic response due to re-orientation of molecular chains called Part B. Both parts are developed within a framework for finite strains. The main constituents are the Neo-Hookean model describing large elastic deformations, the ...
A modified approach for simulating complex compound structures within early design steps
Georg Gruber, Daniel Klein,Sandro Wartzack - University of Erlangen-Nuremberg
Owing to increasing relevance of lightweight design the deployment of compound structures with their beneficial material characteristics becomes more and more important. These growing demands for lightweight design cannot be met by improving constructive details at the end of the development cycle. On the contrary already the early design steps have to be exploited adequately, since these steps offer the highest freedom of design. The ...
A new advanced visco-elastoplastic eight chain rubber model for LS-DYNA
Dr. Tobias Olsson and Prof. Larsgunnar Nilsson - Engineering Research Nordic AB
A new advanced eight chain rubber model has recently been implemented in LS-DYNA. The material is tailored for polymeric materials. The basic theory is taken from Arruda’s thesis from 1993 but it has been enhanced with advanced features such as the Mullins effect, viscoelasticity, plasticity and viscoplasticity. The Mullins effect is described by two different models: the first one is strain based and developed by Boyce in 2004 and the ...
A New Method for CrachFEM ‘Damage’ Parameter Calculation & Transfer from Autoform to LS-Dyna
Michael Buckley - Jaguar Land Rover
Mike Selig - Autoform Development GmbH
Martin Oehm - MATFEM
A novel transversely-isotropic 3D elastic-viscoplastic constitutive law for modeling fiber matrix composites
M. Vogler, R. Rolfes - Leibniz University Hannover
F.X.C. Andrade - University of Porto
J.Schöpfer - Daimler AG
S. Kolling - German Institute for Polymers (DKI)
A transversely isotropic elastic-viscoplastic constitutive law with a novel 3D failure crite- rion is presented, addressing high pressure effects, strain rate sensitivity in yielding and failure and volumetric plastic strain. The constitutive equations are derived in the frame- work of transversely-isotropic invariants, which allow for a coordinate system independent formulation and an easy parameter identification. Triaxiality dependent ...
A pregnant woman model to study injury mechanisms in car crashes
Jérémie Pérès, Michel Behr, Lionel Thollon - IFSTTAR
Kambiz Kayvantash - CADLM
Based on statistical analysis it has been estimated that 3 to 7% of pregnant women experience trauma, 2 third of those trauma are caused by car accidents. According to one epidemiologic study, the frequency of foetal losses could exceed the death frequency of children aged 0 to 4. Some numerical and experimental tools have recently been developed so as to better understand injury mechanisms leading to foetal losses, nevertheless shortcomings ...
About Isogeometric Analysis and the new NURBS-based Finite Elements in LS-DYNA
Stefan Hartmann , David Lorenz - DYNAmore GmbH
David J. Benson - University of California
In the context of isogeometric analysis many research activities have focused on the use of Non- Uniform Rational B-Splines (NURBS). These NURBS-based finite elements have been studied in depth and it has been shown, that they are particularly well suited for computational analysis leading to qualitatively more accurate results in comparison with standard finite elements based on Lagrange polynomials. Due to these motivating results, ...
ALE Incompressible Fluid in LS-DYNA
Nicolas Aquelet - LSTC Livermore
Mhamed Souli - University of Lille
The computation of fluid forces acting on a rigid or deformable structure constitutes a major problem in fluid- structure interaction. However, the majority of numerical tests consists in using two different codes to separately solve pressure of the fluid and structural displacements. In this paper, a monolithic with an ALE formulation approach is used to implicitly calculate the pressure of an incompressible fluid applied to the structure. ...
An airbag application for the ALAR incidences for the Passenger Aircrafts
Vailore Anandan
The airbag system can be designed to reduce the damage on the fuselage during an Approach and Landing Accident Reduction (ALAR) situations as well as ditching in the water for the transcontinental flights. Minimum hull damage protects the passengers in deep waters. A preliminary investigation for this end is performed in this paper. A simple model under 10000 elements is used to investigate the problem. The findings of the LS-DYNA finite ...
An Approach to capture the Ejection Mitigation Requirements of FMVSS 226 with Finite Element Simulations
André Haufe, George Dimitru - DYNAmore GmbH
Andreas Hirth - Daimler AG
Robert Kirchner - Friedmann & Kirchner
An Effective Curve Matching Metric for Parameter Identification using Partial Mapping
Katharina Witowski - DYNAmore GmbH
Markus Feucht - Daimler AG
Nielen Stander - Livermore Software Technology Corporation
This paper describes a new method for curve matching essential to the solution of inverse problems represented by system parameter identification. Hysteretic response curves are specifically addressed as a general class. The method is based on Partial Curve Mapping (PCM) of the experiment curve onto the computed curve. This methodology involves a curve matching metric which is computed using the volume between the test curve and the computed ...
An Overview of User Defined Interfaces in LS-DYNA
Tobias Erhart - Dynamore GmbH
The user-defined features in LS-DYNA are powerful tools that allow users in academia or industry to verify research results in the context of general and complicated finite element applications. Implementation work concerns only the special field of interest, and there is no need for the comprehensive task of developing and maintaining the complete finite element software. The most popular user interface is for material modeling. But there ...
Analysis of a single stage compressed gas launcher behaviour : from breech opening to sabot separation
F. Plassard, J. Mespoulet, P. Hereil - Thiot-Ingenierie
Single stage compressed gas guns are used in Shock Physics laboratory to perform characterization experiments and ballistic events. The main advantage of this kind of launcher is that impact conditions are well defined (impact obliquity, impact velocity). In order to achieve high quality in ballistic performance, it is essential to understand the behaviour of the projectile in the barrel of the gun. This paper is devoted to the simulation of ...
Analysis of Fibre Orientation using μCT Data
Sebastian Mönnich, Robert Glöckner , Florian Becker - German Institute for Polymers (DKI)
Integrative simulations are based on a calculated bre orientation from which the local material properties can be derived in several ways. For instance the micro-mechanical model proposed by Tandon and Weng may be used coupled with an orientation averaging approach to include the bre orientation. This approach then gives the elastic properties of the bre matrix compound with a strong dependency, of e.g. the elastic modulus, on the bre ...
Analysis of formability of advanced high strength steel sheets with phenomenologically based failure criteria with separate treatment of instability, shear and normal fracture
K. Isik, C. Soyarslan, A.E. Tekkaya - Technical University of Dortmund
H. Richter - ThyssenKrupp Steel Europe AG
Despite their wide application in sheet metal forming analysis, Forming Limit Diagrams cannot supply reliable results for the cases involving non-proportional strain paths or material classes with reduced ductility such as advanced high strength steels (AHSS). Fracture criteria appear as complimentary tools for assessment of formability in these cases. CrachFEM, as an advanced failure model, merges an instability criterion that includes ...
Application of LS-DYNA SPH Formulation to Model Semi- Solid Metal Casting
F. Pineau, G. D’Amours - National Research Council Canada, Aluminium Technology Centre
Semisolid metal alloys have a special microstructure of globular grains suspended in a liquid metal matrix. This particular physical state of the matter can be exploited to produce near-net-shape parts with improved mechanical properties. Indeed, semi-solid processes take advantage of a much higher apparent viscosity of the die cast materials by limiting the risk of oxide formed on the free surfaces to become incorporated into the casting ...
Behaviour model for semi-crystalline polymer, application to crashworthiness simulations
R.Balieu, F.Lauro, B.Bennani, B.Bourel - Univ Lille Nord de France
Today polymer materials are frequently used in the transport domain with more severe specification requirements. The behaviour modeling and failure prediction have consequently become a priority. In this paper, an elasto- viscoplastic behaviour model is presented, with non associated plasticity, damage and strain rate effect, which represents the observed behaviours of a semi-crystalline polymer under dynamic loading.
BEM Methods For acoustic and vibroacoustic problems in LS-DYNA
Yun Huang - Livermore Software Technology Corporation
Mhamed Souli - University of Lille
Rongfeng Liu - JSOL Corporation
This paper presents the new developments of finite element methods and boundary element methods for solving vibro-acoustic problems in LS-DYNA. The formulation for a frequency domain finite element method based on Helmholtz equation is described and the solution for an example of a simplified compartment model is presented. For boundary element method, the theory basis is reviewed. A benchmark example of a plate is solved by boundary element ...
bjective evaluation of the quality of the FAT ES-2 dummy model
Christian Gehre - PDB
Sebastian Stahlschmidt - DYNAmore GmbH
Matthias Walz - DAIMLER AG
The numerical simulation is an essential part of the development of the passive safety of vehicles. Robust and predictable computational models are the base of the successful application of those simulations. Crash test dummies and their virtual counterparts are measuring tools to evaluate the injury risks to occupants in car crashes. The progress of those dummy models was remarkable over the past years. By increasing the quality, the ...
Comparison of material models for crash simulation - experimental and simulation work
S. Mönnich, F. Becker - German Institute for Polymers (DKI)
B. Fellner - MAGNA STEYR Fahrzeugtechnik
Complexity based design robustness analysis
Application to mechatronic component (vehicle hatchback )
Computational simulations of aluminum foam projectile behavior
M. Borovinsek, M. Vesenjak, Z. Ren - University of Maribor
S. Itoh - Kumamoto University
The results of experimental tests and computer simulations of open-cell aluminum foam behavior under high deformation rates are presented. Experimental Taylor impact tests showed, that the open-cell foam projectile deforms already during its acceleration in the Taylor barrel. This behavior was investigated further by use of computer simulations with the LS-DYNA. The simulations confirmed very high sensitivity of open-cell foam projectile to ...
Cowper-Symonds material deformation law application in material cutting process using LS-DYNA FE code: turning and milling
Virginija Gyliene, Vytautas Ostasevicius - Kaunas University of Technology
Finite element modeling becomes the huge support in understanding technological process. Besides, there are no so much milling process studies, or these studies are simplified to, as orthogonal cutting process. This paper presents experiences results from orthogonal turning and face milling process. These results were taken for FE model validation and material deformation law constants prediction. In both cases some cutting process ...
Crashworthiness and Sensitivity Analysis of Structural Composite Inserts in Vehicle Structure
Chung-Kyu Park, Cing-Dao Kan, Pradeep K. Mohan - The George Washington University
Steven W. Reagan - L & L Products Inc.
Balachandra R. Deshpande - SimaFore Inc.
This study is focused on identifying influential parameters in numerical analysis of structural composite inserts in vehicle structure. A 3-point bending test of a simplified steel-composite beam structure is conducted to evaluate the crashworthiness of composite insert in steel structure. Empty sections of the beam structure are filled with composite insert and foam filler. From physical 3-point bending tests, it is identified that the two ...
Crashworthiness of an Electric Prototype Vehicle Series
F. Huberth, S. Sinz, S. Herb, J. Lienhard, M. Jung, K. Thoma - Fraunhofer EMI, Freiburg
K. Hochberg, C. J. Fleig - University of Applied Sciences Offenburg
The Shell Eco-marathon (SEM) is a challenge for student teams to develop energy-efficient vehicles and demonstrate the fuel efficiency of their prototypes. In Europe, this takes place at the Lausitz Ring in Germany. Since 2009, the Schluckspecht team has taken part in the Urban Concept category of the SEM. The specification of the vehicles which start in the Urban Concept Group requires resemblance to roadworthy cars. In the last quarter of ...
Deep drawing simulation of α-titanium alloys using LS-Dyna
Sebastijan Jurendić - University of Ljubljana
Silvia Gaiani - University of Modena and Reggio Emilia
Titanium alloys have excellent properties for their target applications; however their use is still limited by high price and formability issues. To avoid extensive on-site trials and to cut development costs, a numerical simulation method is developed for the deep drawing process of α-titanium (hexagonal close packed) alloy sheet using LS-Dyna. The Barlat 1989 material model is adopted for modelling the plastic response of the material ...
Development and verification of a material model for prediction of containment safety of exhaust turbochargers
Dieter Memhard , Florence Andrieux , Dong-Zhi Sun - Fraunhofer Institute for Mechanics of Materials IWM
R. Häcker - Bundesanstalt für Materialforschung und –prüfung BAM
For predicting the containment safety of turbochargers against failure of rotors at elevated temperatures and dynamic loading the complex deformation and damage behaviour of the respective materials has to be determined by appropriate experiments and on the other hand the temperature and strain rate dependency has to be described by a material model to simulate the component behaviour under these complex loading conditions. The ...
Development of a thorax finite element model for thoracic injury assessment
Nestor N. Nsiampa, C. Robbe, A. Papy - Royal Military Academy, Belgium
Kinetic energy non-lethal weapons (KE-NLW) are now widely used by law enforcement, by military forces, by the police in situations where the use of lethal arms is not required or suitable. Unfortunately, their effects are still not well known. Therefore, there is a need to better understand the injury mechanism induced by such projectiles for a better prediction of the risk of injury. This may be beneficial for the manufacturer, the deciders ...
Development of a water filled fender system for off-shore installations
Sean Duvall - AMEC
In order to extend the life and productivity of an off-shore oil and gas platform an new installation has been proposed to provide a compression unit. The existing platform is already extensively occupied, having been in existence for over 25 years, and a new approach was required to facilitate the compression unit. This additional facility is an addition outside the existing envelope of the platform and in line with requirements it must ...
Development of Advanced Finite Element Models of Q Child Crash Test Dummies
Stephen Fu, Christian Kleessen, Zaifei Zhou, Karl Koschdon, Robert Kant - Humanetics
Development of an improved screw model at faurecia
M. Meyer - Faurecia Autositze
Some years ago Faurecia used a very simple screw model. In this model the screw holes are filled by a rigid body and the screw shaft is modeld by a simple spring beam with an unrealistic stiffness. But this model doesn’t represent the behavior of screws in real test. With this simple model it was not possible to get the peeling effect of the holes. And the deformation of the part and the screw was unrealistic. Also the forces inside the screw ...
Development of Detailed AF05%ile Hybrid III Dummy FE Model
Yoichiro Ohnishi, Mariko Mohri, Hayato Kaneko, Tatsuya Komamura, Tsuyoshi Yasuki
This paper describes a development of the Hybrid III AF05%ile dummy FE model to be used for frontal crash simulations. The precise geometries of the dummy were measured at a pitch of 1.0 mm using X-ray CT scans. The material properties and the mechanical responses of the components were measured in static and dynamic tests and were used for the model validation. The FE model results showed a good correlation with the kinematics and injury ...
Development of Frequency Domain Dynamic and Acoustic Capabilities in LS-DYNA
Yun Huang, Mhamed Souli, Cleve Ashcraft, Roger Grimes, Jason Wang - Livermore Software Technology Corporation
Mostafa Rassaian, Jung-Chuan Lee - The Boeing Company
A set of new features for frequency domain dynamic and acoustic computation have been implemented in LS- ® DYNA . They include random vibration and high-cycle fatigue analysis, frequency response functions, steady state dynamics, response spectrum analysis, and acoustic analysis based on boundary element methods or finite element ® methods. The objective of introducing these new features is to add capabilities to LS-DYNA to solve ...
Efficient nonlinear multi-scale modeling of composite structures
Thibault Villette, Jan Seyfarth, Roger Assaker, Laurent Adam - e-Xstream engineering
Efficient Processing of Multiple Contacts in MPP-DYNA
Brian Wainscott - Livermore Software Technology Corporation
Complex models often contain more than just a few contact interfaces. The decomposition of such a model can result in an uneven distribution of these contacts among the available processors. Some contacts may lie wholly on a single processor, while others will be distributed across many or all of the processors. Some processors may have many contacts to handle, and others may have none. This variability can cause inefficiencies which ...
Failure modeling of a self piercing riveted joint using LS-DYNA
Silke Sommer - Fraunhofer Institute for Mechanics of Materials IWM
Johannes Maier - LuK GmbH & Co. KG
Besides the basic product requirements, the aspect of energy efficiency is in the center of automobile engineering. A mixture of different light weight materials like aluminium and higher strength steels, called multi-material mix, is used increasingly to fulfill these requirements and reduce the weight of the vehicles. Hence the challenges for the joining technique are increasing. Mechanical joining techniques like self piercing riveting ...
FEM study of metal rolling in grooved rolls
D.V. Shevchenko, D.Yu. Saraev - Siemens Corporate Technology
A.I. Borovkov, D.L. Nesterenko - St. Petersburg State Polytechnical University
LS-DYNA was used to model the rolling process in grooved rolls. One-pass and two-pass (with rotation of the metal sheet at 90° a fter first pass) rolling in grooved rolls, as well as four-pass rolling in plain rolls and various combinations of these two types of rolling were simulated. With the help of finite-element analysis we estimated the influence of the areas of deformation hardening on the stress-strain state of metal sheet. The ...
Finite element analysis of localised impact loading on short glass fibre- reinforced polyamide engine oil pan subjected to low velocity impact from flying projectiles
Zakaria Mouti, James Njuguna - Cranfield University
Keith Westwood, Darren Long - Eaton, Automotive Group
This paper investigates low velocity impact involving a glass fibre-reinforced polyamide engine oil pan as part of a complete new development of thermoplastic components. The assessment of the impact resistance has driven the need to employ LS DYNA for finite element modelling in order to virtually benchmark and predict the strength and fracture behaviour of stressed plastic parts. In order to develop a reliable predictive capability and to ...
Finite element dynamic simulation of whole rallying car structure: Towards better understanding of structural dynamics during side impacts
E. Nassiopoulos and J. Njuguna - School of Applied Sciences, Cranfield University
Side impact accidents against a tree or pole remain the most dangerous accident scenarios in rally cars. Statistical data shows that 52% of the fatalities between 2004 and 2009 concern crashes against a rigid pole by the track sides, whilst among those more than 60% were side impacts. Despite the present scientific efforts, rallying cars side impacts are still among the least understood primarily due to limited space between the occupant and ...
Hail Impact Simulation on CFC Covers of a Transport Aircraft
P. Starke, F. Mayer - EADS Deutschland GmbH
Due to increasing weight saving requirements in new aircraft, structures traditionally built from aluminium alloys are increasingly replaced by carbon fibre reinforced Composites (CFC). For the preliminary flight clearance hail imact si- mulations were perfomed on CFC covers. For the composite material the authors applied a user- defined material. Behaviour of ice / hail stone was modeled through fitting of parameters for ...
How to Use LS-OPT for Parameter Estimation – hot stamping and quenching applications
Arthur Shapiro - LSTC
The “direct” heat transfer problem is one in which material properties and boundary conditions are specified, and LS-DYNA [1] is used to calculate the temperature response of the nodes in the mesh. The “inverse” heat transfer problem is one in which the temperature response of a node point in the mesh (e.g., a surface node) is specified from experimental measurements, and the objective is to calculate material properties and boundary ...
Hypervelocity impact of aluminium sphere against aluminium plate : experiment and LS-DYNA correlation
F. Plassard, J. Mespoulet, P. Hereil - Thiot Ingenierie
High velocity impact of 3 mm diameter aluminium sphere against thin aluminium target plate has been performed at impact velocity of about 4000 m/s with the two stage light gas gun HERMES at Thiot Ingenierie laboratory. Impacts at normal incidence and with a 32° angle generate debris clouds that were collected by an aluminium witness plate. The visualization of the debris clouds generated after the impact has been realized by using an ultra ...
Impact Simulations on Concrete Slabs : LS-OPT Fitting Approach
Nicolas VAN DORSSELAER, Vincent LAPOUJADE - Alliance Services Plus
Georges NAHAS, François TARALLO, Jean-Mathieu RAMBACH - Institut de Radioprotection et de Sûreté Nucléaire, Fontenay-aux-roses
This paper is based on a work realized for an international OECD benchmark initiated by IRSN and CNSC. The main goal of IRIS_2010 Benchmark was to evaluate the ability of simulation to reproduce experimental tests of impacts on concrete slabs for two different deformation modes: bending (flexural) and punching. LS-DYNA® has been chosen by IRSN as their main explicit code for simulating such high speed impacts on concrete. Most LS-DYNA® ...
Implementation of a Strain Rate Dependent Human Bone Model
Zahra Asgharpour, Erich Schuller, Steffen Peldschus - Institut für Rechtsmedizin der Universität München
Dirk Fressmann - Dynamore GmbH
Strain rate dependency of mechanical properties of cortical bone has been well demonstrated in literature studies. Nevertheless, the majority of these studies have been done on nonhuman bone and at lower magnitudes of strain rates. The need for a mathematical model which can describe the mechanical behavior of bone at lower strain rates as well as higher ones is essential. A human finite element model THUMS (Total Human Model for ...
Improving the Prediction of LS-DYNA Calculations with Rhodia Data and Digimat
Cécile DEMAIN - Lyon Research and Technology Center
imulation of the flow around a Vertical Axis Wind Turbine : LS-DYNA v980
Iñaki CALDICHOURY, Vincent LAPOUJADE - Alliance Services Plus
Hervé LE SOURNE, Abdelhaq ABDELQARI - Institut Catholique d’Arts et Métiers
Facundo DEL PIN - LSTC
The future 980 version of LS-DYNA® will include Computational Fluid Dynamics (CFD) solvers. The main objective of these new solvers will be to perform fluid structure interactions by directly solving the Navier-Stokes equations and by using any LS-DYNA® Lagrangian model for the solid part. In the process of evaluating the new possibilities offered by these new solvers, in particular concerning fluid structure interaction, AS+ has worked in ...
Incompressible CFD Results Using LS-DYNA. For High Reynolds Number Flow Around Bluff Bodies
This report will provide some insight on the new incompressible CFD solver that will be available in version 980 of LS-DYNA. Several test cases were performed by AS+ in order to evaluate the capabilities of these new solvers. These studies were conducted in cooperation with LSTC’s CFD developers. Among the various test cases, the airflow over the Ahmed body, a simplified car model will be presented. The flow around this body reproduces the ...
Influence of HE shape on blast profile
J. Mespoulet, F. Plassard, P. Hereil - Thiot-Ingenierie
A. Lefrançois - CEA
This paper is concerned by the effect of HE geometry on the shape of the blast wave. The aim of this work is to increase the knowledge on pressure profile generated by blast wave so as to optimize the design of explosion chambers. These facilities are commonly designed for spherical HE but most of the customer charges have other geometry (line, plate, cylinder ...). Numerical simulations performed with Multi Materials Arbitrary Eulerian ...