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13th International LS-DYNA Conference

Preload Release in a Steel Band under Dynamic Loading
Eyal Rubin, Yoav Lev (RAFAEL Advanced Defense Systems LTD.)
A steel band is tightened around a thin walled steel cylinder. The assembly is exposed to different dynamic loadings including shock and vibration. While tightening, the circumferential stresses developed in the band, decrease as a function of the distance from the bolts and the value of the coefficient of friction between the band and the cylinder. The cylinder elasticity also affects the amount of force distribution in the band. A rigid ...
Rate Dependent Progressive Composite Damage Modeling using MAT162 in LS-DYNA®
Bazle Z. (Gama) Haque, John W. Gillespie Jr. (University of Delaware)
Performing experiments in numerical space and predicting accurate results are the main research focus of many computational mechanicians. These goals may in general sound challenging, however, makes perfect sense in cases where experiments are not possible, e.g., landing on Mars, sea waves impacting marine structures, crash landing of space shuttle, etc. Composite damage modeling plays a vital role in designing composite structures for damage ...
Response of a Large Span Stay Cable Bridge to Blast Loading
Cezary Bojanowski (Argonne National Laboratory)
Marcin Balcerzak (Warsaw University of Technology)
The computational analysis of engineering structures under blast loads faces three fundamental problems: (i) reliable prediction of blast loads imposed on structures, (ii) correct representation of material behavior, and (iii) global analysis of large scale structures. Despite the recent developments in Finite Element (FE) codes like LS-DYNA® and advancements in computational power, addressing all of these issues in a single simulation ...
Scalability of Implicit LS-DYNA® Simulations Using the Panasas® PanFS® Parallel File System
Bill Loewe (Panasas, Inc.)
As HPC continues its growth with Linux clusters using multi-core processor architectures, the I/O requirements further increase with higher-fidelity CAE modeling and workflow demands. This paper examines the parallel scalability characteristics of LSTC’s Finite Element Analysis software LS-DYNA for up to 288 processing cores for implicit mechanics simulations that have high I/O demands. The motivation was to quantify the performance and ...
Simulating the Impact Response of Composite Airframe Components
Karen E. Jackson, Justin D. Littell (NASA Langley Research Center)
Edwin L. Fasanella (National Institute of Aerospace)
In 2010, NASA Langley Research Center obtained residual hardware from the US Army’s Survivable Affordable Repairable Airframe Program (SARAP), which consisted of a composite fuselage section that was representative of the center section of a Black Hawk helicopter. The section was fabricated by Sikorsky Aircraft Corporation and was subjected to a vertical drop test in 2008 to evaluate a tilting roof concept to limit the intrusion of overhead ...
Simulating the Impact Response of Full-Scale Composite Airframe Structures
Edwin L. Fasanella (National Institute of Aerospace)
Karen E. Jackson, Justin D. Littell (NASA Langley Research Center)
Michael D. Seal (Analytical Mechanics Associates, Inc.)
NASA Langley Research Center obtained a composite helicopter cabin structure in 2010 from the US Army’s Survivable Affordable Repairable Airframe Program (SARAP) that was fabricated by Sikorsky Aircraft Corporation. The cabin had been subjected to a vertical drop test in 2008 to evaluate a tilting roof concept to limit the intrusion of overhead masses into the fuselage cabin. Damage to the cabin test article was limited primarily to the roof. ...
Simulation of Compressive ‘Cone-Shaped’ Ice Specimen Experiments using LS-DYNA®
Hyunwook Kim (Memorial University of Newfoundland)
A laboratory scale compressive cone-shaped ice experiments were performed, and a numerical simulation model using LS-DYNA was developed. Modified material properties were applied based on a crushable foam model (MAT 63) as the ice properties. To simulate a saw-tooth pattern which is commonly observed through experiments in ice, an additional function of failure criteria, which is maximum principal stress, was included. Results of the ...
Simulation of High-Voltage Discharge Channel in Waterat Electro-Hydraulic Forming Using LS-DYNA®
V. Mamutov (St. Petersburg State Polytechnical University)
S. Golovashchenko (Ford Motor Company)
A. Mamutov (Oakland University)
The method of simulating of expansion of plasma channel during high-voltage discharge in water at electro-hydraulic forming (EHF) is developed using finite-element software package LS-DYNA® 971. The energy input into the plasma channel from the discharge circuit is taken into account. The energy deposit law is calculated from the experimentally obtained pulse current and voltage in the discharge circuit measured between the electrodes. The model ...
Simulation of residual deformation from a forming and welding process using LS-DYNA®
Mikael Schill (DYNAmore Nordic AB)
Eva-Lis Odenberger (Industrial Development Centre in Olofström AB)
Predicting the finished geometry of a part is a major issue for the manufacturing industry. This is a complex task, especially if the manufacturing involves several types of processes. In order to succeed, the complete manufacturing process has to be included in the simulation. For sheet metal forming, this has been done for quite some time where trimming, forming and springback are simulated in consecutive order. However, there are other ...
Simulation of Various LSTC Dummy Models to Correlate Drop Test Results
Ken-An Lou (ArmorWorks)
David Bosen, Kiran Irde, Zachary Blackburn (ShockRide)
Hybrid III Anthropomorphic Test Dummy (ATD) is primarily validated for frontal impacts from physical sled tests in an automotive incident but not for a military vehicle incident related to mine blast vertical impacts. Vertical drop tests were conducted using Hybrid III 50th percentile ATD. The purpose of conducting these tests was to identify which LSTC dummy model shows the best correlation with the test results. This paper presents the ...
Simulation-Based Airbag Folding System JFOLD Version 2: New Capabilities and Folding Examples
Shinya Hayashi (JSOL Corporation)
Richard Taylor (Ove Arup & Partners International Limited)
Computer simulation is playing an increasingly important role in the design, development and application of airbag safety systems. As folding patterns and airbag structures become more and more complex, users are turning to simulation based folding solutions to generate accurately folded models in a short space of time. To meet this demand, a new software tool called JFOLD has been developed by JSOL Corporation to enable successful airbag ...
Software for Creating LS-DYNA® Material Model Parameters from Test Data
Eric Strong, Hubert Lobo (Matereality)
Brian Croop (DatapointLabs)
LS-DYNA contains a wealth of material models that allow for the simulation of transient phenomena. CAE Modeler is a generalized pre-processor software used to convert material property data into material parameters for different material models used in CAE. In a continuation of previously presented work, we discuss the extension of the CAE Modeler software to commonly used material models beyond MAT_024. Software enhancements include advanced ...
Soil Modeling for Mine Blast Simulation
Frank Marrs, Mike Heiges (Georgia Tech Research Institute)
This paper presents the results of an effort to correlate an LS-DYNA® simulation of a buried mine blast with published experimental test data. The focus of the study was on simulating the effects of soil moisture content on the blast characteristics. A mathematical model for sand is presented that is based on several previously proposed models. The simulation correlates well with the results of a mine blast experiment, thus validating the ...
Sound Radiation Analysis of a Tire with LS-DYNA
Zhe Cui, Yun Huang (LSTC)
Springback Calculation of Automotive Sheet Metal Sub-assemblies
Volker Steininger, Xinhai Zhu, Q. Yan, Philip Ho (Tiwa Quest AG, LSTC)
In recent years the spring back calculation of a sheet metal part after forming has achieved a high accuracy. Today we are able to calculate the spring back amount after all forming operations of the part including trimming, piercing and reforming. But the spring back of a single sheet metal part is only the first step to solve the problem. What matters at the end is the spring back of the assembly or the sub-assembly of multiple sheet metal ...
TaSC® Product Status
Willem Roux (LSTC)
The LS-TaSC product status is presented. The current capabilities are discussed together with illustrative examples and release dates. In addition, the current development directions, such as new capabilities and CAE integration, are also revealed.
The Optimization of Servo Press Method for Sheet Metal Forming
Jun-Ku Lee, Hyun-Cheol Kim (Theme Engineering, Inc.)
Recently in the field of sheet metal forming, servo press, which can control the speed and position of the tool using a servo motor, is attractive method. Development process of servo press method is accelerated as the capacity of servo motor become bigger. In the future, it’s expected as a great alternative plan to replace conventional press method in order to improve quality, increase productivity, maintain integrity of tools, and reduce ...
The Simulation and Formability Prediction of a DP600 Steel Reverse Draw - NUMISHEET 2014 Benchmark 1
Changqing Du, Kaiping Li (Chrysler Group LLC)
Xiaoming Chen (U.S. Steel Corporation)
Yuzhong Xiao, Xinhai Zhu (LSTC)
In this study, the simulation and formability prediction of the DP600 Steel Revers Draw in the NUMISHEET 2014 Benchmark 1 is conducted using LS-DYNA®. The combinations of the material models and element formulations are evaluated for better strain path correlations between the simulation and the measurement at the specified points. Various input factors are considered in this study, including different material model and element type, mesh ...
Theoretical Development of an Orthotropic Elasto-Plastic Generalized Composite Material Model
Robert K. Goldberg and Kelly S. Carney (NASA Glenn Research Center)
Paul Du Bois (George Mason University)
Canio Hoffarth, Joseph Harrington, Subramaniam Rajan (Arizona State University)
Gunther Blankenhorn (LSTC)
Several key improvements in the state of the art have been identified by the aerospace community as desirable for inclusion in a next generation material model for composite materials to be incorporated within LS-DYNA®. Some of the specific desired features that have been identified include the incorporation of both plasticity and damage within the material model, the capability of using the material model to analyze the response of both ...
Three Dimensional Analysis of Induced Detonation of Cased Explosive
Devon Downes, Manouchehr Nejad Ensan (Aerospace Portfolio, National Research Council)
Amal Bouamoul (Defence Research & Development Canada–Valcartier)
Fragments of aluminum impacting on Composition B explosive encased in rolled homogenous armour (RHA) steel were investigated through the LS-DYNA®. The investigation focused on shock to detonation simulations of Composition B, with the objective of determining both the critical velocity which would generate a shockwave strong enough to cause detonation of the explosive, as well as the resulting pressure profile of the detonation wave. ...
Through-Thickness Element Splitting for Simulation of Delamination in Laminated Composite Materials
Ofir Shor and Reza Vaziri (The University of British Columbia)
The increasing use of laminated composite materials in advanced industrial applications requires the ability to predict their behavior under the expected service loads. Laminated composite materials exhibit various damage and failure mechanisms, which can cause a degradation of their mechanical properties and lead to catastrophic structural failure. The debonding of adjacent laminate layers, also known as delamination, is considered to be one of ...
Topology and Topometry Optimization of Crash Applications with the Equivalent Static Load Method
Katharina Witowski, Heiner Müllerschön, Andrea Erhart, Peter Schumacher (DYNAmore GmbH)
This paper deals with topology and topometry optimization of structures under highly nonlinear dynamic loading such as crash using equivalent static loads. The basic idea of the “Equivalent Static Load”- Method (ESL) is to divide the original nonlinear dynamic optimization problem into an iterative “linear optimization ↔ nonlinear analysis” process. The displacement field of the nonlinear dynamic analysis is transformed to equivalent linear ...
Update in dummy model enhancements and effective pre-processing
Sebastian Stahlschmidt, Alexander Gromer, Reuben D´Souza, Ulrich Franz (DYNAmore GmbH)
The FAT and PDB dummy models have been developed for more than a decade. The models are used by almost all OEMs and restraint system suppliers to enhance the passive safety performance of their vehicles. Nevertheless, the PDB is still launching new projects to further enhance the predictability of the ES-2, ES-2re, BioRID-II and WorldSID models. This paper presents the current enhancement projects at a glance. With the increasing quality of ...
Usage of LSTC_NCAC Hybrid III 50th Dummy in Frontal Occupant Simulation
Ming-Pei Lin, Chih-Min Chang, Cho-Hsuan, Tsai, Chia-Hui Tai, Chun-Te Lee (HAITEC)
Occupant simulation is very useful for vehicle restraint system and passive safety development. Since the requirements of safety assessment are more and more demanding, the occupant simulation models have to be more and more accurate. Dummy model is very crucial in occupant simulation, and is difficult for most vehicle manufacturer to build. To purchase a commercial dummy model is a very reasonable and safe choice. Alternatively, LSTC offers ...
Using LS-DYNA® to Simulate the Thermoforming of Woven-Fabric Reinforced Composites
Corey D. Morris, Lisa M. Dangora and James A. Sherwood (University of Massachusetts)
Thermoforming of fabrics is a composite manufacturing process that has the potential to yield quality parts with production costs and cycle times comparable to the fabrication of stamped metal parts. The thermoforming process, illustrated in Figure 1, begins with alignment of the fabric in a rigid frame. Typically, multiple ply layers are simultaneously stamped into the mold to achieve the desired part thickness and mechanical properties. The ...
Validation of Hydraulic Gas Damper Coupler and Crash Simulation of Large Rolling Stock Model in LS-DYNA®
F Lancelot (ARUP)
YH Zhu2, BH Li, KF Wang, CL Li (Changchun Railway Vehicle Co., Ltd)
The hydraulic gas damper coupler (HGDC) is the most important energy absorbing component in rolling stock crash impact. The HGDC can effectively dissipate crash energy and reduce excessive structural loads at all impact speeds. In this paper, the LS-DYNA material *MAT_HYDRAULIC_GAS_DAMPER_DISCRETE_BEAM (*MAT_070) is used to simulate the HGDC coupler. Using this formulation, both static and dynamic characteristics have been replicated. The ...
Validation of the Simulation Methodology for a Mobile Explosive Containment Vessel
David Karlsson (DYNAmore Nordic AB)
A Mobile Explosive Containment Vessel (MECV) is a chamber for protection against effects caused by explosions and is used to safely secure, contain, transport, store or test explosive materials. The MECV has been tested for a charge equivalent to 8 kg of TNT and strain levels at several positions were measured. These test data were used for comparison and validation of two simulation techniques and if necessary improve the simulation ...
Validation Studies for Concrete Constitutive Models with Blast Test Data
Youcai Wu, John E. Crawford, Shengrui Lan, Joseph M. Magallanes (Karagozian & Case)
Many concrete constitutive models are available for use in LS-DYNA®. A thorough validation related to their applicability for the types of problems at hand should be made before application of any of these models. The process for validating a constitutive model includes examining the results produced with the model related to the behaviors it exhibits, gathering a suite of measured data collection pertinent to the problem to be addressed, and ...
Verification and Validation of a Three-Dimensional Generalized Composite Material Model
Canio Hoffarth, Joseph Harrington, Subramaniam D. Rajan (Arizona State University)
Robert K. Goldberg, Kelly S. Carney (NASA-GRC, Cleveland)
Paul Du Bois (George Mason University)
Gunther Blankenhorn (LSTC)
A general purpose orthotropic elasto-plastic computational constitutive material model has been developed to accurately predict the response of composites subjected to high velocity impact. The three-dimensional orthotropic elasto-plastic composite material model is being implemented initially for solid elements in LS-DYNA® as MAT213. In order to accurately represent the response of a composite, experimental stress-strain curves are utilized as ...
Verification of Concrete Material Models for MM-ALE Simulations
Swee Hong TAN, Roger CHAN, Jiing Koon POON and David CHNG (Ministry of Home Affairs, Singapore)
Although there are many concrete material models in LS-DYNA®, very few appear to be valid for Multi-Material Arbitrary Lagrangian-Euler (MM-ALE) simulations. From a rudimentary point of view, it makes sense at the first instance, that the typical method of verification via simulating cylinder tests in triaxial and/or uniaxial stress states for Lagrangian format should work for MM-ALE as well. This paper shares the experiences gathered from ...