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5th European LS-DYNA Conference

MPP Implicit for LS-DYNA v. 971
Cleve Ashcraft, Roger Grimes, Bob Lucas - LSTC
The Vision • LSTC wants to provide a single package that allows users to perform all of their analyses. – Implicit computations must be integrated with explicit – Linear analyses (useful for debugging large models) must be integrated as well.
Multidisciplinary Optimisation and the Design for 6 Sigma
Dr. Tayeb Zeguer - Jaguar Cars Ltd
New Features in LS-OPT Version 3.0
Nielen Stander, Willem Roux - Livermore Software Technology Corporation
Kevin Brown - University of Nottingham
Richard Brooks, Nicholas Warrior
Thermoplastic composites are being considered for application in vehicle bumper and front-end structures for increased pedestrian protection. This paper describes recent progress in the calibration and validation of LS-DYNATM material model 162 (*MAT_COMPOSITE_DMG_MSC) for the modelling of impact damage in the glass/polypropylene commingled fabric thermoplastic composite, TwintexTM. In this study, MAT 162 is calibrated by using a series ...
Numerical simulation of ground impact after airdrop
Yves de Lassat de Pressigny - Centre d’Essais en Vol, MinDef/DGA/DE, France
Vincent Lapoujade - CRIL Technology, France
The airborne forces of many countries use honeycomb paper as energy damping material (EDM) for heavy cargo airdrop. Its roughly constant crushing resistance makes the dimensioning of the kinetic energy absorber layer quite easy. Yet the velocity and attitude of a parachute at ground impact is variable, due to weather conditions, or undamped pendulum movement of the load under the parachutes. Those parameters have a big influence on the ...
Numerical simulation the bottom structures grounding test by LS-DYNA
Ainian Zhang, Katsuyuki Suzuki - The University of Tokyo,
Nonlinear finite element method (FEM) is a powerful tool for analyzing ship collision and grounding problems. The reliability of the numerical simulation results largely depends on the proper definition of problem and careful control of some critical parameters. The purpose of the paper is to study the effect of selected parameters on crashworthiness of the single-hull bottom structure due to raking. The quasi-static grounding process is ...
On the Optimization of the Punch-Die Shape: An Application of New Concepts of Tools Geometry Alteration for Springback Compensation
A. Accotto, G. Anedda, M. Sperati, R. Vadori - Altair Engineering Srl
This work here presented concerns the activities of stamping tools alterations of an automotive component done thanks optimization technologies. The process of nominal geometry alteration of a complete stamping die is traditionally based on the experience of the try-out people who manually modify the tools in order to compensate geometrical differences due to springback under a Trial-and-Error approach and often the restroking die needs so ...
Perforation of Composite Floors
William Algaard, John Lyle, Conrad Izatt - Arup
Rapid construction methods for multi storey buildings involve maximising the tasks that can be carried out simultaneously on site. The risks of construction workers, fitting out lower floors, being hit by large objects dropped during installation can be managed by understanding the protection provided by the intermediate floors. This paper describes a Finite Element based methodology for assessing the impact event using LS-Dyna. The aim of ...
Post-test simulation of airliner wing access panel subject to tyre debris impact
R. S. Birch, D. Karagiozova, R. A. W. Mines - University of Liverpool
C. Bergler, M. Kracht - CADFEM GmbH
The purpose of the investigations described in this paper is a simulation approach for tyre debris impact on wing access panels. Aircraft tyre rubber has a complex structure containing directional layers of nylon reinforcement embedded in the rubber matrix. Material properties of the compound have been derived from quasistatic compression and tensile tests with specimen cut in circumferential and axial direction of the tyre, i.e. with ...
Productivity Gain in Crashworthiness Simulation EASi-CRASH for Complete Safety and Crash Modeling for LS-DYNA
Shivakumar Shetty, Petter Sahlin - ESI Group
The pre and post-processing for crashworthiness and safety simulation in automotive development projects is constantly changing. New functionality of the solver requires evolutionary updates, while the paradox of combining reduced lead times with an ever increasing range of regulatory tests calls for more dramatic improvements and innovative approaches. Hence the changes, the underlying need is constant – to increase productivity in model ...
Recent Development for Metal Forming Simulation
Yasuyoshi Umezu, Ninshu Ma - The Japan Research Institute, Ltd., Japan
Since 1996, Japan Research Institute Limited (JRI) has been providing a sheet metal forming simulation system called JSTAMP-Works packaged the FEM solvers of LS-DYNA and JOH/NIKE3D, which might be the first multistage system at that time and has been enjoying good reputation among users in Japan. To match the recent needs, “faster, more accurate and easier”, of process designers and CAE engineers, a new metal forming simulation ...
Self-piercing riveting
Andre Stühmeyer - CAD-FEM GmbH
Overview • The self piercing riveting process • FE analysis of the joining process – Large deformation – Material failure – 2D remeshing approach – 3D remeshing approach • Comparison with experiments • Process optimization with FEA • Summary
Shape Optimization of a Vehicle Crash-box using LS-OPT
Marcus Redhe, Larsgunnar Nilsson - Engineering Research Nordic AB
Fredrik Bergman - Saab Automobile AB
Nielen Stander - LSTC
The aim of this project is to optimize the geometry of a crash-box due to impact at low velocity impact. The optimization problem is solved in LS-OPT, using Neural Networks as meta-model. The Neural Networks meta-model has been evaluated on a small test example and it shows remarkable good approximation of the responses. The geometry was parameterized using HyperMorph. In addition to the geometry parameters, the sheet thickness and the ...
Side Member Crumple Section Simulation and Structural Optimization
Taian Chen, Clive Chirwa, Wei Wang, M. Mao - The University of Bolton
Energy absorbing structural component in a car front impact The study shows the energy management of the front end structure it’s stiffness, strength and crush mode as function of occupant load. A well designed front end structure will have loads well below the tolerance limit of actual injury criteria (FMVSS 208, ECE R94) Progressive tube axial crushing and s-shape tube bending are commonly used as energy absorbers This paper presents ...
Simulation of Hydrodynamic Ram and Liquid Aeration
S.C.McCallum, D.D.Townsend - BAE SYSTEMS
During the past several years, research within BAE SYSTEMS has concentrated on developing a capability for simulating Hydrodynamic Ram (HRAM). In this paper we demonstrate how the ALE technique in LS-DYNA can be used to simulate the principal stages of HRAM with liquid aeration. LS-DYNA is used to simulate the impact of a small steel sphere at 2km/s into a water-filled container manufactured from 3.2 mm thick aluminium alloy L165. ...
Simulation of the Crash Performance of Crash Boxes based on Advanced Thermoplastic Composite
Matthias Hörmann - CADFEM GmbH, Germany
Marco Wacker - Jacob Composite GmbH, Germany
Because of their superior mechanical properties in combination with a relative low density Fiber Reinforced Composites (FRC) are of great potential in the area of lightweight structures respectively applications. Consequently FRC is gaining influence and acceptance not only in the automotive industry. Unfortunately the application of endless reinforced composites with duroplastic matrix was mainly restricted by a production technique ...
Simulation of Wave-Dissipating Mechanism on Submerged Structure using Fluid-Structure Coupling Capability in LS-DYNA
Sunao Tokura, Tetsuji Ida - The Japan Research Institute, Ltd.
Understanding the wave-dissipating mechanism of seashore structures is important to design effective seashore protection system against high waves. From the engineering point of view, wave dissipation with seashore structures is considered as a kind of fluid-structure interaction (FSI) problem. Recently constructing a submerged structure "flexible mound" is increasing for some advantages. The flexible mound is made of rubbery material and ...
The Applicability of the Universal HP-MPI to MPP LS-DYNA on Linux Platforms
Yih-Yih Lin
In addition to its parallel algorithm, MPP LS-DYNA for cluster computing derives its parallelism from the MPI library and the interconnect. MPI has always had a standard since its inception. On the other hand, there are diverse interconnects and switches in the market, each with unique low-level interface and performance considerations. This variety of interconnects has resulted in a difficult support burden for LSTC, the software ...
The Application of Optimization and Robustness Technology to a Martian Lander Concept
Paul Sharp,Royston Jones - Altair Engineering Limited
Richard Slade - Astrium Limited
Optimization and robustness technologies provide a gateway for the rapid assessment of an engineering design. Following the development of a design concept, optimization technology can automatically modify design variables of the system (i.e. airbag geometry, vent area etc.) to achieve the optimum performance characteristics. Once the design has been optimised, a robustness assessment can be performed. This culminates in the determination ...
The influence of bird-shape in bird-strike analysis
S.C. McCallum, C. Constantinou - BAE SYSTEMS
This paper describes the results of simulations to assess the influence of bird shape during bird-strike. In the first part of this paper, simulations are presented which compare the results of a traditional bird shape model (hemispherical ended cylinder) impacting a square flat panel using the ALE and SPH techniques. In each case the bird is modelled with a mass of 8 lb and has physical dimensions (torso) representative of a Canadian ...
The Optimization of the LSTC Hybrid III Dummies to enhance the numerical stability and to fulfill the current standards
Wolfgang Lietz - CAD-FEM GmbH
• Many years ago LSTC developed Hybrid III-Dummies. One group of these have on the outer surface deformable parts. The dummies are free and without charge for user’s of LS-DYNA. • In the last years on on hand the dummies changed and on the other hand the expectations on the dummies were growing. • This paper describes the the overall validation and optimization process of the whole dummy and in detail the optimization work for ...
The thick shell element type 3
Andre Stühmeyer - CAD-FEM GmbH
The use of an Oasys PRIMER model management database during accelerated vehicle development programs such as the 2005 Ford GT
Tim Keer, Simon Iregbu - Arup
The role of CAE (Computer Aided Engineering) in the automotive vehicle development process continues to grow in importance. CAE has been one of the key enablers in the recent reduction of vehicle development times, as it allows less reliance on time-consuming and costly prototype testing. Impact CAE has been at the forefront of this CAE revolution. Various additional factors continue to place increased demands on the impact CAE team: ...
The “Shaken Baby” Syndrome; Computational Studies of a New Hypothesis of its Cause
J.Cheng, S. Cirovic, I.C. Howard, A. Yoxall, M.A. Parsons - The University of Sheffield
The term “shaken baby syndrome” refers to a unique pattern of non-accidental traumatic injury occurring in children by shaking. Typical injuries include subdural haemorrhage, retinal haemorrhage as well as tears to cortical bridging veins. Infants younger than 6 months are significantly more vulnerable to the shaken baby syndrome than older infants and children, a fact that has been difficult to reconcile with all previous explanations of ...
Tool Design for a High Strength Steel Side Impact Beam with Springback Compensation
Trevor Dutton - Dutton Simulation Ltd
Richard Edwards, Andy Blowey - Wagon Automotive Ltd
Prediction of formability for sheet metal pressings has advanced to a high state of confidence in recent years. The major challenge is now to predict springback and, moreover, to assist in the design of tooling to correctly compensate for springback. This is particularly the case for materials now being routinely considered for automotive production, such as aluminium and ultra high strength steels, which are prone to greater degrees of ...
Topology optimization in crashworthiness design
Larsgunnar Nilsson - Engineering Research Nordic AB and University of Linköping
Jimmy Forsberg - University of Linköping
Topology optimization has developed rapidly, primarily with application on linear elastic structures subjected to static loadcases. In its basic form an approximated optimization problem is formulated using analytical or semi-analytical methods in order to perform the sensitivity analysis. When an explicit finite element method is used to solve contact-impact problems, the sensitivities cannot easily be found. Therefore, an alternative ...
Using LS-DYNA Implicit for Metal Forming Applications
Cleve Ashcraft, Roger Grimes, Xinhai Zhu - LSTC
Validating Material Information for Stochastic Crash Simulation Part 1: Quasi-Static Properties
P.K.C Wood, C. A. Schley, S. Kenny - University of Warwick
T. Dutton - Dutton Simulation
This paper describes the steps in validating material information for stochastic simulation using a quaisi-static tensile test experiment. Sources of physical noise usually present in a testing environment such as variation in material properties, geometry and boundary conditions are included as inputs to Finite Element models. This work is carried out in the context of a research project supported by the Automotive Industry in the ...
Vehicle Roof Crush Modelling & Validation
Mingzhi Mao, E. C. Chirwa,T. Chen - The University of Bolton, UK
Real roof crush tests, quasi-static or dynamic, have been widely used to evaluate the safety integration of vehicle structure, especially in the USA, where there are specified standards such as FMVSS 208 and 216. Europe is endeavouring to reach the same target for vehicle safety taking into account the different road condition. However, carrying out full experimental tests is shown to be costly and in many cases unrepeatable. That is why ...
WorldSID 50th The Next Generation Side Impact Dummy
Bhavik Shah, Yi Liu - FTSS