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10th International LS-DYNA Conference

Concepts toTake Elastic Tool Deformations in Sheet Metal Forming into Account
A. Haufe, D. Lorenz - DYNAmore GmbH, Germany
K. Roll, P. Bogon - Daimler AG, Germany
In recent years the development of more and more niche products, i.e. cars with different external appearance, has become a remarkable trend in the automotive industry. This trend, however, generates higher costs for individual tooling geometries that are traditionally made as stiff as possible. A second trend is the increasing use of high and ultrahigh strength steel grades for bodies in white. Here too the design philosophy for the tools in ...
Metal Forming Applications using Implicit Mechanics Features of LS-DYNA
Roger G. Grimes, Xinhai Zhu - Livermore Software Technology Corporation
The authors will present the use of LS-DYNA for a variety of metal forming applications. They will present some new features and improvements in Version 971 of LS-DYNA such as Inertia Relief and Contact Penetration Detection. The presentation will include applications of gravity loading, binder wrap, flanging, springback and die transfer.
Preliminary Results for an Isogeometric Shell
David J. Benson - Dept. of MAE, UCSD
Yuri Bazilevs, Thomas J. R. Hughes - ICES, The U.T. Austin
Piecewise continuous Lagrangian polynomials are the traditional interpolation functions used in the finite element method. They work well for many applications, but they also have shortcomings for many important applications. For example, in metal forming, the dies are designed using CAD programs and their geometry is defined in terms of NURBS (non-uniform rational B-splines) which can not be exactly replicated with a piecewise ...
Application of Scrap Shedding Simulation in Stamping Manufacturing
Diane Xu - Ford Motor Company
Jim Kosek - Engineering Technology Associates, Inc.
One of the most critical issues in stamping manufacturing today is the successful shedding of scrap from limited trim dies. Until recently, die tryout was the first opportunity to check the shed scrap feasibility of a trim die. The newly developed scrap shed analytical module can be used for analyzing trim die scrap shed feasibility before die creation. It simulates Scrap shedding during or after the die is designed using Dynaform and ...
Mortar Contact Algorithm for Implicit Stamping Analyses in LS-DYNA
Thomas Borrvall - Engineering Research Nordic AB, Sweden
A challenging task for the static implicit nonlinear solver in LS-DYNA is to accurately and robustly solve contact problems, especially is this needed for stamping simulations. This paper aims at investigating the benefits of a mortar segment-to-segment contact algorithm by Puso and Laursen [1,2] when compared to the traditional node-to- segment approach. A penalty based version of the algorithm is implemented in LS-DYNA, meaning that the ...
Sheet Metal Forming Simulation and Real World Tooling
Matt Clarke - Continental Tool and Die
Jeanne He - Forming Simulation Technology LLC
In a modern day draw simulation; our objective has always been to verify the formability of the deformed blank. We then utilize the output of the simulation to ascertain the forces required to form the part. Little time is spent attempting to verify if our design for the die is capable of reproducing these results. Most simulation assumes the tools are rigid. The real expertise comes when you can reproduce that scenario in an actual tool ...
Visions and Latest Developments in Dynaform
Arthur Tang, Jeanne He - Engineering Technology Associates, Inc.
DYNAFORM has been evolved from a Draw Die analysis tool to a Die System analysis tool kits. As the simulation technology and computer resources have been growing rapidly, more demands emerges from different stage of the product and process development sector. Stamping simulation technology is facing more challenges. Based on LS- DYNA ® implicit and explicit solver, DYNAFORM provide simulation tools that support not only the ...
Novel HPC Technologies for Scalable CAE: The Case for Parallel I/O and File Systems
Stan Posey - Panasas, Inc., Fremont, CA, USA
As HPC continues its aggressive platform migration from proprietary supercomputers and Unix servers to HPC clusters, expectations grow for clusters to meet the I/O demands of increasing fidelity in CAE modeling and data management in the CAE workflow. Cluster deployments have increased as organizations seek ways to cost- effectively grow compute resources for CAE applications, and during this migration many also implemented conventional ...
The Performance of 10-Million Element Car Model by MPP Version of LS-DYNA® on Fujitsu PRIMEPOWER
Mitsuhiro Makino - Computational Science and Engineering Solution Center, Fujitsu Limited
In automotive industries, car crash analysis by finite element methods is a very important tool for reducing the development time and cost. In order to get the accurate results, in addition to the improvement of the finite element technology, such as full-integrated shell elements, smaller size of finite element mesh is used, because finer meshes represent the car geometry more accurately, and reduce the noise of contact force. The batch mesh ...
Optimizing LS-DYNA® Productivity in Cluster Environments
Gilad Shainer, Swati Kher - Mellanox Technologies
Increasing demand for computing power in scientific and engineering applications has spurred deployment of high- performance computing (HPC) clusters. Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) are computational technologies that can take advantage of HPC clusters for increasing engineering design productivity, reduce development cost and faster time to market. The end-user benefits are far more ...
Intel Cluster Ready Support for LS-DYNA®/MPP
Tim Prince - Intel Corporation
The Intel Cluster Ready program enables LS DYNA/MPP users to buy, install, and use clusters more effectively. It includes a joint Intel and cluster supplier certification process to ensure the cluster the LS-DYNA user purchases is designed and built to specification. Intel supplied software tools support verification of initial and ongoing operation and performance of the cluster.
LS-DYNA Performance Improvements with Multi-Rail MPI on SGI Altix ICE Clusters
Olivier Schreiber, Michael Raymond, Srinivas Kodiyalam - SGI
Multi-Rail networks can improve MPI communication performance by distributing the communication traffic to multiple independent networks (rails). Messages are divided into several chunks and sent out simultaneously using multiple rails. With the dual plane network topology of SGI Altix ICE clusters, MPI communication can hence utilize both the InfiniBand rails, including, ib0 and ib1 fabrics. The performance gains achievable with LS-DYNA ...
Comparison of ALE and SPH Simulations of Vertical Drop Tests of a Composite Fuselage Section into Water
Karen E. Jackson, Yvonne T. Fuchs - NASA Langley Research Center Hampton
Simulation of multi-terrain impact has been identified as an important research area for improved prediction of rotorcraft crashworthiness within the NASA Subsonic Rotary Wing Aeronautics Program on Rotorcraft Crashworthiness. As part of this effort, two vertical drop tests were conducted of a 5-ft-diameter composite fuselage section into water. For the first test, the fuselage section was impacted in a baseline configuration without ...
An Implicit Incompressible CFD Solver in LS-DYNA for Fluid-Structure Interaction Problems
Facundo Del Pin - Livermore Software Technology Corporation
The present work is an introduction to a new CFD solver in LS-DYNA®. This solver is part of the efforts put in LS- DYNA with the objective to expand the capabilities into new challenging problems in industry. The new CFD solver will focus on fluid-structure interaction (FSI) applications where incompressible fluids interact with the existing structures in LS-DYNA. Incompressible flows are present in a great variety of industrial applications ...
2D to 3D ALE Mapping
Nicolas Aquelet - Livermore Software Technology Corporation
Mhamed Souli - Laboratoire de Mecanique de Lille
A 2D MMALE (Multi-Material Arbitrary Lagrange Euler) code was implemented in LS-DYNA®. Like the 3D MMALE already available each 2D computational cycle is divided in two steps. First a multi-material version of the two-dimensional shell formulations solves the physical problem on quadrangle meshes during the Lagrangian step. The 2D shell formulations are plane strain and area-weighted axisymmetric. An advection step adapted to the 2D shell ...
Using the New Compressible Fluid Solver in LS-DYNA CESE Solver and the Input File Setup
Zeng-Chan Zhang - Livermore Software Technology Corporation
In this new compressible fluid solver, the conservation element and solution element (CESE) method[1, 2] is used. The CESE method is a novel numerical method for solving conservation laws and it has many nontraditional features, such as: • Space and time conservation ⎯ Flux conservation can be maintained very well both locally and globally in space & time. • Accurate ⎯ It is 2nd order for both flow variables and their ...
Simulation of Ballistic Impact on Composite Panels
Matti Loikkanen - Propulsion Engineering Technology & Research
Grama Praveen - Global Research Center, General Electric Company
David Powell - University of California, Berkeley
Ballistic impact on composite panels is studied in this work both experimentally and computationally. The purpose was to develop computational methods to analyze a high speed jet engine fragment impacting on composite targets. 12 inch by 12 inch laminated panels with 8, 16, and 32 plies and the standard +-45, 0 /90 degree stacking sequences were considered. With the nominal ply thickness of 0.0075 inches, the corresponding panel thicknesses ...
LS-DYNA® Impact Simulation of Composite Sandwich Structures with Balsa Wood Core
L. J. Deka, U. K. Vaidya - The University of Alabama at Birmingham
The impact damage response of balsa core sandwich composite plates with S2-glass/ epoxy reinforced facesheets is evaluated by impacting them with a spherical steel projectile at single impact locations. The impact damage can significantly reduce the structural integrity and load bearing capacity of a composite structure. Under high velocity impact loading, laminated composites experience significant damage causing fiber breakage, matrix ...
The Use of LS-DYNA® Models to Predict Containment of Disk Burst Fragments
Eric Stamper, Steven Hale - CAE Associates Inc.
Turbomachinery manufacturers commonly test the centrifugal strength of their rotors in a vertical axis spin test, often called a disk burst test. The design of the containment shell that encloses the disk burst event is critical to ensure the safety of the area surrounding the test. A common method used to design the containment shell for a turbine disk burst test is based on the assumption that the kinetic energy lost by the disk fragments ...
Application of the SPH Method for Simulation of Aerospace Structures under Impact Loading
M-A Lavoie, A. Gakwaya1 - Laval University, Cité Universitaire, Quebec, Canada
M. Nejad Ensan - National Research Council, Ottawa, Ont. Canada.
The SPH method is applied in industrial level problems as encountered for example in studies related to bird impact on composite aircraft structures. This paper first demonstrates the accuracy of the method for bird impact on rigid target modeling and then applies the developed model to a more complex problem, namely the secondary bird impact.
Studies on Behavior of Carbon and Fiberglass Epoxy Composite Laminates under Low Velocity Impact Loading using LS-DYNA
Bhushan S. Thatte, Gautam S. Chandekar, Ajit D. Kelkar - North Carolina A&T State University
Pramod Chaphalkar - Grand Valley State University
The desired characteristics of materials in modern aircraft applications require high specific modulus and high specific strength for low specific weight. Composite structures, fabricated using carbon and glass fabrics in conjunction with epoxy resin manufactured via the heated vacuum assisted resin transfer molding (H-VARTM) process are now being considered as a low cost alternative to conventional materials without compromising ...
A Simple Global/Local Approach to Modeling Ballistic Impact onto Woven Fabrics
M. P. Rao, M. Keefe - University of Delaware, Newark
B. M. Powers, T. A. Bogetti - United States Army Research Laboratory, Aberdeen Proving Ground
The objective of this study is to develop and demonstrate the feasibility of an LS-DYNA® Global/Local model for studying the non-linear mechanics of woven fabrics under ballistic impact. The presented approach is built on the observed response of fabrics in experimental studies performed at the Army Research Laboratory (ARL). In particular, two-layer test patches of 600 denier Kevlar KM2® fabrics are modeled with the aim of ...
A Heterogeneous Constitutive Model for Reinforced Carbon-Carbon using LS-DYNA
Kelly S. Carney, Robert K. Goldberg, J. Michael Pereira - NASA Glenn Research Center, USA
Ryan S. Lee, Jeremie J. Albert - The Boeing Company
Reinforced Carbon-Carbon (RCC) is a ceramic matrix, coated C/C composite used in the Space Shuttle’s thermal protection system. A constitutive model for RCC is presented that separates the coating and substrate within a multi-material shell element allowing for bending strains to be accurately computed during a finite element analysis. Version 971 of LS-DYNA contains a new shell element formulation that allows for different ...
A Cyclic Damaged Plasticity Model: Implementation and Applications
Yuli Huang, Stephen A. Mahin - University of California at Berkeley
In analysis and design of structures subjected to earthquakes, the cyclic and dynamic nature of the response leads to complications. Material models need to account for cyclic plasticity, including deterioration and eventual failure due to low-cycle fatigue. A cyclic damage plasticity model MAT_DAMAGE_3 (MAT_153, LSTC 2007) is implemented to combine Armstrong-Frederick/Chaboche nonlinear kinematic hardening, isotropic hardening, and Lemaitre ...
The Influence of Permanent Volumetric Deformation on the Reduction of the Load Bearing Capability of Plastic Components
P.A. Du Bois - Consultant, Germany
S. Kolling - Gießen University of Applied Sciences, Germany
M. Feucht - Daimler AG, Germany
A. Haufe - DYNAmore GmbH, Germany
During the past years polymer materials have gained enormous importance in the automotive industry. Especially their application for interior parts to help in passenger safety load cases and their use for bumper fascias in pedes- trian safety load cases have driven the demand for much more realistic finite element simulations. For such applica- tions the material model 187 (i.e. MAT_SAMP-1) in LS-DYNA® has been developed. In the present ...
Simulation of Composite Tubes Axial Impact with a Damage Mechanics Based Composite Material Model
Xinran Xiao - General Motors Corporation
Composite tube axial impact is a benchmark problem measuring the predictive capability of composite crash simulation. A previous work revealed that MAT58 in LS-DYNA®, a continuum damage mechanics (CDM) composite material law based on Matzenmiller-Lubliner-Taylor (MLT) model, is inadequate in representing the unloading response of composite tubes that form continuous fronds in axial impact testing. To address the issue, two approaches have ...
Simulation of Energy Absorption in Braided Composite Tubes through Axial Crushing
Carla McGregor, Reza Vaziri - The University of British Columbia, Canada
Xinran Xiao - General Motors Corporation
Modeling damage propagation and energy absorption in composite tubular structures under axial compression is a challenging task due to the complex nature of damage growth in composites. In this paper, our model (CODAM for COmposite DAMage), which is incorporated into LS-DYNA® as a user material model, is used to simulate the axial crushing response of braided composite tubes. Recent improvements to the finite element model include the ...
Finite Element Modeling of Preloaded Bolt Under Static Three-Point Bending Load
Ken-An Lou, William Perciballi - ArmorWorks
The objective of this project was to develop innovative lightweight mine-protected fasteners for blast protection appliqués. Blast protection appliqués are used on tactical and combat ground vehicles as a method of deflecting or mitigating the effects of anti-vehicular mine blasts or attack by Improvised Explosive Devices (IEDs). A critical and weakest component of these appliqués is the fastener joints. Currently, industrial bolts are ...
Finite Element Simulation using SPH Particles as Loading on Typical Light Armoured Vehicles
Geneviève Toussaint, Robert Durocher - Defence Research and Development Canada – Valcartier
Light Armoured Vehicles (LAV) are essential to transport troops and equipment in combat and high risk zones. The emergence of non conventional threats such as Improvised Explosive Devices (IED) implies a need to reassess armoured vehicle design to improve crew survivability. To do this DRDC has been developing new experimental facilities and has conducted experimental testing to study armoured vehicle structure subjected to near field ...
Novel Multi-scale Modeling of Woven Fabric Composites for use in Impact Studies
Gaurav Nilakantan, Michael Keefe, John W. Gillespie Jr. - University of Delaware
Travis A. Bogetti - US Army Research Laboratory
A novel approach to the multi scale modeling of the impact of woven fabrics using LS-DYNA® has been presented. This new technique entitled ‘Hybrid Element Analysis (HEA)’ incorporates the use of different finite elements at both a single and multiple level of modeling. A yarn level resolution is maintained around the impact zone or local region, while a homogenized resolution has been used for the far field or global region. The central patch ...
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