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7th European LS-DYNA Conference

Numerical investigation of draw bending and deep drawing taking into account cross hardening
Clemens Barthel, Till Clausmeyer, Bob, Svendsen - University of Technology,Dortmund, Germany
Sheet metal forming is one of the most important manufacturing processes. Computer simulation has become the tool for modeling such processes and also for predicting the springback in the final part. The talk will deal with two different metal forming processes, namely draw bending and deep drawing of a cup. In the draw bending case a metal strip is clamped into a testing device in such a way that it is bent over a roller. The strip is then ...
Numerical Investigations to Determine Sources for the Scatter of the BioRID Dummy
S. Stahlschmidt - DYNAmore GmbH
A. Hirth - Daimler AG
The BioRID v2.5 model is in a very fine validation state until now. In some new tests for further validation of the model, one can observe a very strong scatter in some major signals of the tests. Some of these signals are used to calculate injury criteria which are used to determine the quality of a seat in rear crash scenarios in consumer tests. This paper describes the new validation test setup and gives an overview about the latest ...
Numerical simulation of low-velocity impact loading of polymeric materials
H. Daiyan, F. Grytten, E. Andreassen, R.H. Gaarder, E.L. Hinrichsen - SINTEF Materials and Chemistry
O.V. Lyngstad - Plastal AS
H. Osnes - University of Oslo / Simula Research Laboratory
Simulation of ductile polymers subjected to impact loading has become an important topic [1, 2], especially for automotive components related to passenger and pedestrian safety. The aim of our work is to establish and validate numerical models for impact response, and this presentation will focus on a study of impact on injection molded polypropylene plates. SAMP-1 (Semi-Analytical Model for Polymers) [3] was selected as constitutive model ...
Numerical Simulation of the Critical Blast Wave of Mines on APV's Crew Members
Alon Brill - Netvision
Paul A. Du Bois - Consulting Engineer
Blast wave generated by energy released when a mine is detonated, travels through the air at supersonic velocity. Has a high pressure front and hits a vehicle in about 100 μm giving rise to overpressure on it. Blast created by expanding explosion products and air moving behind shock front; results in dynamic pressure on a vehicle. Soil ejecta thrown up when mines are buried in the ground; augment significantly impact of blast ...
On Adaptive Finite Element Analysis in Structural Dynamics of Shell-Like Structures - A Specific View on Practical Engineering Applications and Engineering Modelling
Karl Schweizerhof - Universität Karlsruhe / DYNAmore GmbH
Stephan Kizio - Universität Karlsruhe
Adaptive Finite element analysis in structural analysis has reached a fairly mature status; however, in practice only fairly little is visible in engineering applications. This contribution gives an overview over some major aspects with a specific focus on structural dynamics of shell-like structures. Adaptive analysis in structural mechanics is mainly focusing on static problems where a large number of linear and nonlinear tasks in 3D ...
On Constitutive Equations for Dummies
B. Feng, J. Hallquist - LSTC
Constitutive equations, which may be used for modeling dummies during impact, are presented. In addition, a unified constitutive equation, for dummies and rubber-like materials, is presented. The new constitutive equation applies to elastic, viscoelastic, incompressible as well as compressible materials. Some special cases, e.g., neo-Hookean, Mooney-Rivlin, Ogden incompressible, Ogden compressible, and many currently used constitutive ...
On Predicting Lower Leg Injuries for the EuroNCAP Front Crash
Thomas Hofer - Altair Engineering GmbH
Peter Karlsson - Saab Automobile AB
Niclas Brännberg - Altair Engineering AB
Lars Fredriksson - Altair Engineering GmbH
Validation of occupant lower leg injury performance is a difficult procedure due to the complex interaction between occupant and vehicle structure. As a starting point, a carefully validated structural model is crucial to ensure the accurate load of the occupant model in terms of acceleration and applied forces. However, even after a tedious validation of structural performance and occupant environment, the calculated tibia values might ...
Optimization and robustness of complex material model simulations with modeFRONTIER
Marco Perillo, Vito Primavera, Luca Fuligno - EnginSoft SpA
Giulia Fabbri, Casper Steenbergen, Nicolò Pasini - Automobili Lamborghini SpA
Experimental quasi-static and dynamic tests were conducted over different types of advanced material samples, such as composite sandwich, in order to derive both mechanical and numerical input parameters for LS-DYNA material models. The characterization of models addressed to reproduce the behaviour of real materials takes great importance in order to simulate accurately complex phenomena such as crash tests and impact events. This work ...
Optimization study of a parametric vehicle bumper subsystem under multiple load cases using LMS Virtual.Lab and OPTIMUS
Laszlo Farkas, Cédric Canadas, Stijn Donders, Tom Van Langenhove, Nick Tzannetakis - LMS International
Johan Tielens, Danny Schildermans - PUNCH Metals N.V.
This paper deals with the design and optimization of a vehicle bumper subsystem, which is a key scenario for vehicle component design. More than ever before, the automotive industry operates in a highly competitive environment. Manufacturers must deal with competitive pressure and with conflicting demands from customers and regulatory bodies regarding the vehicle ...
Performance of the Hybrid LS-DYNA on Crash Simulation with the Multicore Architecture
Yih-Yih Lin - Hewlett-Packard Company
Jason Wang - Livermore Software Technology Corporation
Using crash simulation models, we investigate the multicore performance of the newly developed hybrid LS-DYNA, a method whose speedup arises from both shared-memory and message-passing parallelisms. Theoretically, the hybrid method gains performance advantages over the traditional, message-passing-parallel (MPP) LS-DYNA for two reasons. First, the addition of shared-memory parallelism to the message-passing parallelism reduces the number of ...
Practical Examples of Efficient Design Optimisation by Coupling VR&D GENESIS and LS-DYNA
David Salway, GRM Consulting Ltd. UK.
Paul-André Pierré, GRM Consulting Ltd. UK.
Martin Liebscher, Dynamore GMBH, Germany
With the ever increasing demand for the efficient use of materials to reduce manufacturing costs and product mass; the use of optimisation techniques have become common place in CAE. The optimisation techniques used for optimising in the non-linear domain, and those used for linear domain problems have until recently been distinctly separate philosophies. For instance topology optimisation would be used with linear static analyses, but could ...
Process Chain Forming to Crash: Efficient Stochastic Analysis
Tanja Clees, Daniela Steffes-lai - Fraunhofer Institute for Algorithms and Scientific Computing SCAI
Martin Helbig - Fraunhofer Institute for Mechanics of Materials IWM
Karl Roll, Markus Feucht - Daimler AG
During the fabrication of products, important material and process parameters, geometry and also external influences (e.g. room temperature) can vary considerably. It is known that they can have a substantial, even critical influence on the quality of the resulting products. Therefore, software tools and strategies supporting an efficient and thorough analysis of sensitivity, stability and robustness aspects as well as a multi-objective ...
Progressive Damage Modeling of Plain-Weave Composites using LS-Dyna Composite Damage Model MAT162
Dr. Bazle A. Gama, Prof. John W. Gillespie Jr. - University of Delaware
Dr. Travis A. Bogetti - US Army Research Laboratory
Progressive damage of plain weave S-2 Glass/SC15 composites under in-plane tension, compression, and shear, through-thickness tension and compression, and transverse interlaminar and punch shear loading is presented for a unit single element using the MAT162 composite damage model in LS- Dyna. While the detail formulation of the MAT162 material model can be found in the Keyword user's manual [1], the main objective of this paper is to ...
Quicker Process to Consider Strain Hardening for Crash Analysis Using HYCRASH
Sayaka ENDOH, Takahiko MIYACHI, Yasuyoshi UMEZU - JSOL Corporation
As one of the important issues in correlation of crash analysis, we know that the press-forming effect has large influence for the result of the analysis. Some tries and studies were carried out to assume the forming result to the crash analysis. However these actions haven’t spread to the actual product development because of some difficulties. We mark the Inverse Solver to solve this issue and have developed the new solver HYCRASH, ...
Recent Developments in LS-DYNA
Dr. John Hallquist - LSTC
In this presentation Dr. John O. Hallquist, founder and president of Livermore Software Technology Corporation (LSTC), will give an overview about recent developments in LS-DYNA. LS-DYNA is a highly advanced general-purpose nonlinear finite element program that is capable of simulating complex real world problems. The distributed memory solver provides very short turnaround times on Unix, Linux and Windows clusters. The major development ...
Reliability-based Multi-Objective Optimization and Visualization using LS-OPT Version 4
Nielen Stander, Willem Roux, Tushar Goel- Livermore Software Technology Corporation
David Björkevik, Christoffer Belestam - Engineering Research AB
Katharina Witowski - DYNAmore GmbH
This study expounds the multi-objective optimization of a realistic crashworthiness problem with special reference to the incorporation of uncertainty and the visualization of the Pareto Optimal Frontier (POF). LS-OPT® and LS-DYNA® are used for the optimization based on the C2500 truck model developed by NHTSA. The design problem is set up as a Reliability-Based Design Optimization (RBDO) problem which includes specifications for the ...
Selecting Material Models for the Simulation of Foams in LS-DYNA
Brian Croop,Hubert Lobo - DatapointLabs
Foams are multi-phase materials that exhibit dramatically different properties that depend on the matrix material as well as the pore microstructure. This additional degree of freedom from the presence of the gas phase makes material modelling for foams a difficult matter. LS-DYNA offers a variety of material models, each with capabilities designed to capture the unique behaviour of a different types of foam. The selection of the correct ...
Simplified FE Simulation of Frontal Occupant Restraint Systems
Richard Brown, David Coleman, Ian Bruce - Jaguar Land Rover
A biofidelic flexible pedestrian legform impactor (Flex-PLI) has been developed by Japan Automobile Manufacturers Association, Inc. (JAMA) and Japan Automobile Research Institute (JARI). The Flex-PLI has good biofidelity as well as several knee ligament elongation measurement capabilities, three femur and four tibia bending moment measurement capabilities. For these reasons Flex-PLI is likely to be used for future pedestrian Global Technical ...
Simulation of a clamping ring under high dynamic loading
S. Edelmann, C. Groß, H. Chladek - INPROSIM GmbH
Clamping rings are used in a wide range of mechanical applications in order to assemble two or more cylindrical parts, e.g. tubes and pipes, pressure vessels and tanks. Another application area of clamping rings is in turbo engines, where they connect compressor, bearing and turbine casings for example. For normal operating conditions, standard rules or simple static analyses are adequate to determine the relevant design parameters of this ...
Simulation of acoustic and vibroacoustic problems in LS-DYNA using boundary element method
Yun Hang - Livermore Software Technology Corporation
Mhamed Souli - University of Lille Laboratoire Mecanque de Lille
Rogelio Perez - Schneider Electric Industries Calcul & Simulation
The present work concerns the new capability of LS-DYNA® in solving acoustic and vibroacoustic problems. In vibroacoustic problems, which are assumed to be weak acoustic-structure interactions, the transient structural response is computed first. By applying the FFT, it is transformed into a frequency response. The obtained result is taken as boundary condition for the acoustic part of the vibroacoustic problem. Consequently, the radiated ...
Simulation of Crack Propagation using Damage- Driven Fission Adaptivity Coupled with Element Erosion or Node Splitting
Torodd Berstad, Cato Dørum - Structural Impact Laboratory (SIMLab) / SINTEF Materials and Chemistry
Odd Sture Hopperstad, Tore Børvik - Structural Impact Laboratory (SIMLab) / Department of Structural Engineering
A novel method for simulation of crack propagation has been developed in LS-DYNA. The method combines damage-driven fission adaptivity and element erosion or node splitting to simulate crack propagation in the finite element mesh. A damage model is used to describe the evolution of material damage with plastic straining and fracture is assumed to occur at a critical value of the damage parameter. Coupled or uncoupled damage models may be ...
Simulation of Dynamic Delamination and Mode IEnergy Dissipation
Muhammad Ilyas, Christine Espinosa, Frédéric Lachaud, Michel Salaün - Université de Toulouse
Delamination initiation and propagation of aeronautic composites is an active field of research. In this paper we present a methodology for critical energy release rate correlation of numerical simulation and experimental data. Experiments of mode I critical energy release rate were carried out at quasi static and pseudo dynamic loading rates. Cohesive finite elements are used to predict the propagation of delamination in a carbon fiber and ...
SPH Formulations: New Developments in LS-DYNA
J. L. Lacome - Livermore Software Technology Corp
“Standard” SPH methods are based on an Eulerian kernel. In most cases, the support remains constant and the neighbors search is carried out at each time step. This allows to deal with large deformation problems. However, this technique may suffer from instabilities (such as the so-called tensile instability [Xiao 05]). In the case of a Lagrangian kernel, the neighbors’ list remains constant throughout the calculation. This formulation ...
SPH Simulations of High Velocity Impacts on Concrete Plate
Dr. Tatsuo Sakakibara, Dr. Toru Tsuda and Ryo Ohtagaki - ITOCHU Techno-Solutions Corporation
The local damages of the concrete plate are produced by high velocity impact of rigid projectile. In order to represent the cracking or perforation behaviours of the concrete, SPH is appropriate method because of completely mesh free. In this paper, SPH simulations for the local damage of the concrete plate due to high velocity impacts are performed to study the effects of the impact velocity and the strength of the concrete plate. To ...
Strain Rate Induced Strength Enhancement in Concrete: Much ado about Nothing?
Leonard E Schwer - Schwer Engineering & Consulting Services
When concrete impact and penetration simulations are discussed, the question of increased strength due to high strain rates arises. Many concrete material modelers cite and use the seminal work of Bischoff and Perry (1991), or the widely accepted standard reference for concrete Comite Euro-International du Beton (1993) or CEB for short. Bischoff and Perry amassed a large amount of concrete laboratory data addressing strain-rate induced Dynamic ...
Structural Crashworthiness of Rail Vehicles - from the Requirements to the Technical Solutions
Dr. Markus Seitzberger, Richard Graf, Dr. Philipp Heinzl, Andreas Rittenschober - Siemens Transportation Systems GmbH & Co KG
Sebastian Haupt, Gerhard Schmidt - Siemens AG
Rail transit provides a very safe means of public transport, which is due to the railroad specific principle of track guidance in combination with high active safety measures during operation. However, train accidents cannot totally be excluded and in the last two decades the subject of passive safety has become an issue of growing importance also in the railway industry. Administrations, operators, railway research institutes, and ...
Study of the Behavior of Dummy Hybrid III Upper Extremities
Sascha Kutschenreuter, Maxime Dagonet - Takata Petri AG
Studies of crash simulations resulted in the assumption that an interaction of the upper occupant extremities with the vehicle interior has effects on the occupant loadings, e.g. the chest acceleration. Quantifying this effect requires a dummy model also valid for the area of upper extremities. A suitable test procedure shall help to identify possible force paths via the arms into the dummy torso and, as a ...
SuperLIGHT-CAR - the Multi-Material Car Body
Lutz Berger, Micha Lesemann, Christian Sahr - RWTH Aachen University
Simon Hart, Richard Taylor - ARUP
Over the last years, total vehicle weights have risen significantly. With their direct influence on the power demand of vehicles, the reduction of weight is one among other measures in order to decrease the fuel consumption and CO2-emissions. The European project SuperLIGHT-CAR (SLC) is aiming at a weight reduction for the body-in-white (BIW) of a compact class passenger car, following the multi- material approach. By this, the perfect ...
Taking into Account Glass Fibre Reinforcement in Polymer Materials: the Non Linear Description of Anisotropic Composites via the DIGIMAT to LS-DYNA Interface
Dr. Jan Seyfarth, Dr.-Ing. Matthias Hörmann - CADFEM GmbH
Dr.-Ing. Roger Assaker - e-Xstream Engineering
Chandra S. Kattamuri, Bastian Grass - BSH Bosch und Siemens Hausgeräte GmbH
In the context of light weight construction the replacement of metal parts with substitutes made from plastic plays a major role. These devices commonly are manufactured through injection moulding and reinforced by different amounts of glass fibres to enhance the strength of the material. In everyday application this poses a challenge to the engineer as due to this processing the local orientation of the reinforcements is varied on a broad ...
Today’s Challenges in Crash Simulation
Jürgen Kohler, Thomas Frank, Markus Feucht - Daimler AG
Crashworthiness simulations of car body structures are an important part of the CAE development chain for car design. In recent years, the requirements on passive safety of cars have grown to high standards, leading to a permanent demand on an increase in simulation accuracy. Additionally, demands on fuel efficiency and CO2-reduction are confronting the car body designers with the need of weight reduction to an immense effort. One way to ...
Topology and Geometry Based Structure Optimization using Implicit Parametric Models1 and LS-OPT
H.Zimmer, M.Prabhuwaingankar - SFE GmbH
F.Duddeck - Privatdozent
Today’s vehicle development process demands for quick evaluation of new designs considering the various attributes in the conceptual phase. Various CAx tools and methods are essential to realize these assessments in a very narrow time frame. New design variants with desired criteria should be quickly created and analyzed. Beside NVH behavior and other criteria crash safety needs to be addressed too as early as possible. Synergy in CAE ...
Use of the FTSS Modular Crash Dummy Models in Frontal Occupant Simulation
Richard Brown - Jaguar Land Rover
Legal and consumer crash tests use crash dummies as the key measurement device in the assessment of crash severity. The dummies are complex assemblies in themselves, and sophisticated DYNA FE models are available, with a significant amount of validation testing to support them. In a large vehicle crash model, the dummy is typically responsible for 10-20% of the CPU time, and there is no strong motivation to reduce its size; in fact, the tendency ...
Using LS-Dyna for Hot Stamping
Arthur B. Shapiro - LSTC
Presented is a methodology for finite element modeling of the continuous press hardening of car components using ultra high strength steel. The Numisheet 2008 benchmark problem BM03 [1] is selected as the model problem to be solved. LS-DYNA [2] has several features that are useful to numerically model hot sheet metal stamping, such as: (1) modeling high rate dynamics for press forming; (2) conduction, convection and radiation heat transfer; ...
Variable Complexity Modeling for Speeding Up Multi- Run-Design-Tasks with Computationally Expensive Simulations
Dr.-Ing. Holger Wenzel - SIMULIA SLM Europe
Optimization and the improvement of robustness and reliability in the early stages of the product development is often attempted today using simulation methods together with algorithms that run these simulations in an automated manner. In this context the need often arises, to run the simulation models with small changes of the geometry hundreds to tenth of thousands times. If these simulations are computationally expensive, like a full ...
Verification of cylindrical interference fits under impact loads with LS-Dyna
Prof. Dr.-Ing. Helmut Behler, Jan Göbel, M.Eng. - Hochschule Mannheim
Steffen Heute, M.Eng. - Alpha Engineering Services GmbH
Interference fits are a commonly used means to couple shafts and wheels for example. The usual dimensioning is performed by a static verification. As long as the system geometry is not too complicated and the deformation is assumed to be linear elastic, the interference pressure can easily be calculated with the more familiar solutions of the equations of elasticity. The maximum static contact forces can be calculated together with an ...
Virtual engineering and planning process in sheet metal forming
Dr. Wolfram Volk, Pierre Charvet - BMW AG
Nowadays the engineering and planning process in sheet metal forming is fundamentally supported by CAD and CAE systems. Beside the full 3D design process of parts and tools the simulation of sheet metal forming processes has established itself in the last 15 years within standard industrial practises. Nevertheless the virtual engineering and planning consists of more than just CAD and CAE tools. For a coordinated and effective process it is ...
Wood and wood products - linking multiscale analysis and structural numerical simulations
Karin Hofstetter, Josef Eberhardsteiner, Reinhard Stürzenbecher, Christoph Hackspiel - Vienna University of Technology
Wood is one of the oldest construction materials known to man. Over thousands of years it has been mainly used in a craft framework, so that current design rules are often based on experience and tradition. The scientific knowledge about the material behavior is often surprisingly poor. In order to exploit the extraordinary ecological potential of the material and to enable its structural use also in an industrial framework, improved ...