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15th International LS-DYNA Conference

Detroit, 2018

Detail Design Evaluation of Extruded Sections on a Body-in-White Concept Model
Satchit Ramnath, Emily Nutwell, SIMCenter, The Ohio State University, Columbus, OH, USA;
Nikola Aulig, Honda Research Institute Europe GmbH, Offenbach/Main, Germany;
Kurtis Horner, Honda R&D Americas Inc., Raymond, OH, USA
Topology optimization allows for the design of structures with an optimum distribution of material for a given set of load cases. In the past, it has been shown that topology optimization can be implemented for a design space representing a body-in-white vehicle structure undergoing multiple load requirements. Using a Hybrid Cellular Automata algorithm along with a scaled energy weighting approach, both the objective of maximizing stiffness as ...
Developing a Numerical Model for Human Brain under Blast Loading
Atacan Yucesoy, Thomas J. Pence, Ricardo M. Alvarez, Michigan State University, East Lansing, MI 48824;
Adam M. Willis, Michigan State University, East Lansing, MI 48824, San Antonio Military Medical Center, Fort Sam Houston, TX 78234
Blast-induced traumatic brain injury (bTBI) is one of the widespread causes of mortality and morbidity for military personnel. Exploring the mechanics of brain tissue is critical to predicting intracranial brain deformation and injury resulting from severe blast loading. This capability would help in obtaining a prognosis and choosing adequate neurosurgical procedures before a physical intervention takes place. In this conference paper, the aim ...
Development and Validation of a Finite Element Model of an Energy-absorbing Guardrail End Terminal
Yunzhu Meng, Costin Untaroiu, Department of Biomedical Engineering and Virginia Tech, Blacksburg, VA, USA
Guardrail end terminals are installed along roads to minimize the severity of vehicle crashes by avoiding their contact with fixed objects along the road. Energy-absorbing guardrail end terminals are designed to help preventing the rail from spearing through the car in an end-on collision as well as to dissipate significant amounts of the striking vehicle energy after the collision while keeping the rate of deceleration tolerable for the ...
Development and Verification of an Orthotropic Elasto-Plastic Three-Dimensional Model with Tabulated Input Suitable for Use in Composite Impact Problems
Robert K. Goldberg, NASA Glenn Research Center, Cleveland OH;
Kelly S. Carney and Paul DuBois, George Mason University, Fairfax VA;
Bilal Khaled, Loukham Shymasunder, Canio Hoffarth and Subramaniam Rajan, Arizona State University, Tempe AZ;
Gunther Blankenhorn, Livermore Software Technology Corporation, Livermore CA
A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in the composite impact models currently available in LS-DYNA® is under development. In particular, the material model, which is being implemented as MAT 213 into a tailored version of LS-DYNA being jointly developed by the FAA and NASA, incorporates both plasticity and damage within the material model and utilizes ...
Development of a One-Step Analysis for Preforming of Woven Carbon Fiber Composites
aDanielle Zeng, Jeff Dahl, Ford Motor Company, Dearborn, MI, USA;
Xinhai Zhu, Li Zhang, Houfu Fan, Livermore Software Technology Corporation, Livermore, CA, USA
Carbon fiber reinforced composites are drawing great attention in automotive industry due to their lightweight, high stiffness and strength properties. Carbon fiber prepregs with resin material pre-impregnated in various architectures of fiber fabrics are preformed to a designed part shape before final compression molding of the parts to reduce production cycle time and achieve high product quality. The current numerical simulation techniques ...
Development of LSTC WorldSID Dummy Finite Element Model (50th Percentile Male)
Fadi Tahan, Dhafer Marzougui, Cing-Dao Kan, Center for Collision Safety and Analysis, George Mason University;
Umashankar Mahadevaiah, Consultant;
Christoph Maurath, Livermore Software Technology Corporation
A finite element model in LS-DYNA® of the WorldSID 50th Percentile Male Dummy has been developed by the Center for Collision Safety and Analysis at George Mason University (CCSA – GMU) in collaboration with Livermore Software Technology Corporation (LSTC). The dummy parts have been meshed and were assembled based on the dummy 2-D and 3-D drawings that the World Side Impact Dummy (WorldSID) Task Group designed and approved under the direction of ...
Development of New Simulation Technology for Compression Molding of Long Fiber Reinforced Plastics using LS-DYNA®
Shinya Hayashi1, JSOL Corporation, 2-18-25 Marunouchi, Naka-ku, Nagoya, Aichi, 460-0002, Japan;
Hao Chen, Wei Hu, Livermore Software Technology Corporation, 7374 Las Positas Road, Livermore, Ca 94551, USA
Composite materials like fiber reinforced plastics (FRP) are becoming more widely used in the automotive industry and have been found very effective in reducing vehicle weight. Recently, long carbon fiber reinforced thermoplastics are increasingly being used for lightweight structural parts with high stiffness, strength and energy absorption performance. Compression molding is considered one of the most efficient manufacturing processes to ...
DIC-based Full-Field Calibration using LS-OPT®: An Update
Stander,N, Basudhar,A, Gandikota,I, Du Bois,S, Kirpicev,D, Livermore Software Technology Corporation, Livermore, CA;
Witowski,K, Ilg,C, Haufe,A, DYNAmore GmbH, Stuttgart, Germany;
Svedin,Å, DYNAmore Nordic, Linköping, Sweden
This paper extends a 2017 study on full-field calibration using Digital Image Correlation (DIC) and the Finite Element Method to identify parameters of a material model developed for elastoplasticity. DIC is an optical method which provides full-field displacement or strain measurements for mechanical tests of materials and structures. It can be combined with the corresponding fields obtained from a Finite Element Analysis to identify ...
Discussion on NVH Analysis with Various Eigensolvers in LS-DYNA
Zhe Cui, Yun Huang, Roger Grimes, Livermore Software Technology Corporation
NVH (Noise, Vibration and Harshness) analysis is a new area of application of LS-DYNA in automotive industry, in addition to the existing applications of crashworthiness and occupant safety analysis. NVH analysis heavily relies on the eigenmode solutions of the structures. Due to the increasing size of the finite element models of automotives and parts, a fast and efficient eigensolver is strongly preferred. During the past two years, a new ...
Dynamic Constitutive Model for Polymers with Considering Strength-Differential Effect and Strain Rate Dependency
T. Tsuda, ITOCHU Techno-Solutions Corporation, Umeda, Kita-ku, Osaka, Japan;
A. Abe, R. Akita, ITOCHU Techno-Solutions Corporation, Kasumigaseki, Chiyoda-ku, Tokyo, Japan;
T. Numata, Sumitomo Bakelite Co., Ltd., Murotani, Nishi-ku, Kobe, Japan;
K. Mimura, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Japan;
S. Tanimura, Emeritus Professor of Osaka Prefecture University and of Aichi University of Technology
It is known that the dynamic behavior of polymers depends greatly on not only the strain rate but also the hydrostatic pressure, and furthermore, the volumetric change after plastic deformation is larger than that of the metal material. Therefore, it is necessary to clarify these material properties for high precision simulation of polymers. In this study, we newly extended the Tanimura-Mimura 2009 model to simulate the dynamic behavior of ...
Dynamic Design Analysis Method to Evaluate Shipboard Shock in LS-DYNA®
Michael Koehler, William McCoy, Milan Patel, U.S. Navy – Naval Surface Warfare Center, Dahlgren Division
The Dynamic Design Analysis Method (DDAM) provides a method for analyzing shipboard components that are subjected to a shock event due to an underwater explosion. Typically, these events are caused by a near miss explosion that results in a severe shock event due to the transient motion of the ship or submarine from the forces imparted on the hull of the vessel.
Effect of Explosive Charge Geometry on Boundary Surface Peak Pressure with Regard to Standoff Distance
oseph Hamilton, Daniel Coleman, Karagozian & Case, Inc., 700 N. Brand Blvd., Suite 700, Glendale, CA 91203
In an effort to better understand the effect of explosive charge geometry on blast effects, in particular with regard to standoff distance, this paper presents a study of three different geometries at varying standoffs. The geometries reviewed in this study were: cylinder, sphere, and rectangular cuboid. The explosive mass was held constant between all geometries, and the system was modeled with the LS-DYNA® structured Arbitrary Lagrangian-Euler ...
Efficiency Improvement of Seat Belt Pull CAE Analysis by Technology and Process Changes
Ligong Pan, Sushanth Ramavath, Seung Hyun Jung, Luis Hernandez, Randall Frank, Core CAE Methods, Digital Innovation, Ford Motor Company;
Hai Truong, Core Seats & Restraints, Ford Motor Company;
Yuzhao Song, Body Exteriors, Ford Motor Company
This work addresses the capabilities of LS-DYNA® and LS-PrePost® in reducing the run-time for quasi-static and dynamic analysis involving large models using the following commands, *DEFORMABLE_TO_RIGID_AUTOMATIC and *CONTROL_MPP _DECOMPOSITIO_TRANSFORMATION. CAE analysis of seat belt pull assessments for FMVSS regulations is often a time consuming task with each iteration running overnight. This paper describes a new methodology that ...
Evaluation of Aircraft Structures Crashworthiness Behavior using Finite Element Analysis
C. Zinzuwadia, G. Olivares, L. Gomez, H. Ly, H. Miyaki, Wichita State University, National Institute for Aviation Research, Computational Mechanics Laboratory, Wichita, KS 67260-0093
Despite ongoing worldwide research and discussion regarding broad aspects of airplane crashworthiness, no specific dynamic regulatory requirement currently exists. However, the Federal Aviation Administration (FAA) requires an assessment of each new aircraft model to ensure that the airplane crash performance will not significantly deviate or otherwise degrade from typical dynamic characteristics found in previous designs [8]. The increased ...
Evaluation of LS-DYNA® Corpuscular Particle Method – Passenger Airbag Applications
Chin-Hsu Lin, Yi-Pen Cheng, General Motors
A uniform pressure method, i.e. no pressure variation on bag surface and location, in LS-DYNA has been commonly used to simulate airbag deployment and interaction of airbag with the occupants. Another newly developed LS-DYNA CPM (Corpuscular Particle Methodology) has gained recognition and acceptance recently because it considers the effect of transient gas dynamics and thermodynamics by using a particle to represent a set of air or gas ...
Evaluation of the Injury Risks of Truck Occupants Involved in a Crash as a Result of Errant Truck Platoons
Hanxiang Jin, Yunzhu Meng, Alexandrina Untaroiu, Costin Untaroiu, Virginia Tech, Blacksburg, VA;
Roshan Sharma, Chiara Silvestri Dobrovolny, Texas A&M Transportation Institute, College Station, TX
Platooning is an extension of Cooperative Adaptive Cruise Control (CACC) that realizes automated lateral and longitudinal vehicle control while moving in tight formation with short following distances. The truck platoons are expected to include at least five trucks with drivers in the first and the last trucks. This paper discusses the methodology and presents results of a single tractor-van trailer impact into a concrete barrier, which is a ...
Experience with Material and Fracture Modeling at FCA US LLC
Experiments and Simulations of Explosives: Shock Wave Propagation around a Convex Structure
N. Van Dorsselaer, S. Eveillard, S. Trélat, Institut de Radioprotection et de Sûreté Nucléaire (IRSN) 31, Avenue de la Division Leclerc, 92260 Fontenay-aux-Roses, France
IRSN provides technical support to the relevant French authorities involved in the security of nuclear material, nuclear facilities and in the transportation of nuclear material. In order to improve its knowledge on blast wave propagation, IRSN has set-up a laboratory scale able to perform detonations of solid explosives against rigid structures (no damage or deformation). In July, 2017, the 7th experimental campaign was conducted on this set-up ...
Explicit and Implicit Simulations for Die-Less-Hydroforming- Structures including Welding, Forming and Load Capacity using LS-DYNA® and DynaWeld®
Andreas Metzger, Thomas Ummenhofer, Karlsruhe Institute of Technology, KIT Steel & Lightweight Structures
Within the scope of Die-Less-Hydroforming, two or more flat metal blanks that have the same cutting-geometry are stacked congruently one above the other, and are then seal-welded on their common edges. Afterwards, the resulting seal-welded double- or multi-layered blank is inflated by a medium (e.g. water) whereby it transforms to a spatial structure under continuous internal pressure increase. Since no external forming tool is used, and because ...
Facing Future Challenges in Crash Simulation Engineering – Model Organization, Quality and Management at Porsche
Marcel Koch, Dr. Ing. h.c. F. Porsche AG;
Steffen Mattern, DYNAmore GmbH;
Robert D. Bitsche, SCALE GmbH
Numerical simulation has become an indispensable tool in car crash analysis, reducing the number of physical experiments and driving the engineering process. While the predictive capabilities of the simulation models have greatly increased in recent years, so has the level of detail, the complexity and the number of load cases analyzed. Dealing with these complexities can become a burden distracting engineers from their main task: the vehicle ...
Fatigue Life Prediction of Composite Adhesive Joints using LS-DYNA®
Ala Tabiei and Wenlong Zhang, Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, Ohio 45221, USA
Composite and adhesive joints are used increasingly in the automotive industry and an active research area is the fatigue analysis of adhesive joints. In this paper, a methodology to predict the fatigue life of adhesive joint is proposed and implemented into LS-DYNA with the joint modeled using a user-defined cohesive material. Fatigue crack growth rate is used to obtain the fatigue damage accumulation rate in cohesive zone model. Our method is ...
Fluid Flow Modeling with SPH in LS-DYNA®
Edouard Yreux, Livermore Software Technology Corporation
A new Smoothed Particle Hydrodynamics formulation for fluid flow modeling has been added in LS-DYNA. A density smoothing algorithm based on kernel density estimation is implemented to correct for the well-known pressure oscillation issue that arises with traditional SPH schemes when modeling fluids. A Weakly-Compressible equation of state is adopted to ensure reasonable timestep restrictions while minimizing the compressibility effects of the ...
Fluid Structure Interaction Simulation of Hood Flutter
James Dilworth, Ben Ashby, Peter Young, Arup
Fluid structure interaction problems appear in a wide range of industries, including automotive, marine and aerospace. In the automotive industry, the drive to make components lighter can also reduce their stiffness, causing them to deflect significantly under aerodynamic loads. The deflections can affect the aerodynamic properties of the vehicle, cause dynamic fluctuations that are visible to the driver, or even lead to failure. The ...
Forming Simulation for Fiber Reinforced Thermoplastic with Introduction to J-Composites
Masato Nishi, Sean Wang, Shaun Dougherty, JSOL Corporation, Harumi Center Bldg. 2-5-24 Harumi, Chuo-ku, Tokyo, 104-0053, Japan
Fiber reinforced composites are good alternatives for metals used in load transmission structures. The increasing requirement for high performance and weight reduction in industry has gradually expanded the use of composites. Finite element analysis as an alternative approach to experimental study is effective in designing fiber reinforced composite products because there are many design parameters. Process/process-chain simulations are ...
FSI Capabilities for the CESE and Chemistry Solvers in LS-DYNA®
Kyoung-Su Im, Zen-Chan Zhang, Grant Cook, Jr., Livermore Software Technology Corp.
Recently, we have developed a new class in the area of compressible flow, gaseous explosion, and FSI for users to assist from the fundamental problems to very complex high level FSI problems by using CESE and Chemistry solvers in LS-DYNA. In this presentation, we will give a step-by-step explanation about the main goal of the class, overviews of the compressible and chemical kinetics theories,the current capabilities of solvers, and the ...
FSI Simulation of a Double-deck Bus Cornering under Crosswind Effects
Castro, H. G, UTN FRRe, UNNE-IMIT, CONICET, Argentina;
Paz, R. R., Del Pin, F., Caldichoury, I., Huang, Ch-J., LSTC, Livermore, California, USA
Every road vehicle under motion experiences forces and moments caused by different sources. One of these sources is the wind. Several investigations have dealt with the effects of wind over road vehicles. Nowadays, it’s a common practice to include also the dynamic characteristics of the vehicle. Particularly, high sided road vehicles (e.g., double-deck buses) are highly demanded and have its center of mass in a relatively high location, so in ...
Generating Experimental Data for a Three-Dimensional Generalized Composite Material Model
Bilal Khaled, Nathan Holt, Loukham Shyamsunder, Canio Hoffarth and Subramaniam D. Rajan
School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ;
Robert K. Goldberg, NASA-GRC, Cleveland, OH;
Kelly S. Carney and Paul DuBois;
George Mason University, Fairfax, VA;
Gunther Blankenhorn,LSTC, Livermore, CA
A three-dimensional orthotropic elasto-plastic composite material model is being implemented in a special version of LS-DYNA® as MAT213. The model is driven by experimental data that describe the elasto-plastic deformation behavior, coupled and uncoupled damage, and failure. This paper documents the test procedures to characterize the material behavior via tensile, compressive, shear and off-axis tests of as well as tests to generate ...
Getting Your Model ‘Right’ – Checking Before, During and After Your LS-DYNA® Analysis
Gavin Newlands, Arup
To be able to capture more and more detail in an analysis, LS-DYNA models continue to increase in size and complexity. A model can now commonly have ten to twenty million elements and it is essential that checking procedures are used to ensure that the model is ‘right’. As element count increases, checking a LS-DYNA model can be a difficult process as many of the checks can be very complex. Having robust methods for checking a keyword deck both ...
High Strain Rate Testing and Material Modeling of an Anisotropic Glass Fiber Filled Polyetherimide
Sean Teller, Ph.D., Jorgen Bergstrom, Ph.D., Veryst Engineering, Needham, MA
High strength composite polymers are often used in applications that require high impact strength and durability. Accurately characterizing the mechanical behavior for FE simulation requires testing the materials at high strain rates and may require multiple loading modes. Veryst Engineering has developed high-strain rate experimental facilities for testing all classes of polymers. We tested 30% glass-fiber filled Polyetherimide (PEI) at ...
HPC in the Cloud: Gompute Support for LS-DYNA® Simulations
Iago Fernández, Gompute S.L.U.
During the last decades, companies have been introducing CAE simulations as part of their product development with the main objective of improving reliability and reducing the costs of prototyping. It is nowadays demonstrated that introducing simulations during an early step of the product design process reduces the risk of failure as well as the associated costs, when the prototypes need to be redesigned.
ICFD: Summary of Recent and Future Developments
Since its release in R7 the Incompressible CFD solver (ICFD) has been rapidly improving and increasing its functionality. In this paper a summary of the latest and current developments will be presented. The focus will be on four topics. First the steady state solver and its coupling capabilities for fluid-structure interaction (FSI) or conjugate heat transfer (CHT) will be presented. In second place the recent modifications to the boundary ...
IIHS Side Impact Parametric Study using LS-DYNA®
Reichert, R., Kan, S., George Mason University, USA;
Arnold-Keifer, S., University of Stuttgart, Germany;
Mueller, B., Insurance Institute for Highway Safety, USA
Side impact crashes are the second most common reason for vehicle passenger deaths after frontal crashes. In 2003, the Insurance Institute for Highway Safety (IIHS) introduced its side impact crash test using a Moving Deformable Barrier (MDB) to encourage manufacturers to implement safety improvements, including side airbag coverage and stronger side structures, in most vehicle models. While many vehicles were rated poor in the beginning of ...
Impact Test Simulation for Nuclear Power Plant Safety under Tornado Disaster
Sunao Tokura, Tokura Simulation Research
In recent years, the safety standards of nuclear power plants against natural disasters, e.g., earthquake, tsunami, tornado, have been extremely intensified in Japan. Regarding the influence of tornadoes, the magnitude and the wind velocity of tornado and the geometry, dimensions, mass, impact velocity and other properties of the missiles from tornado are regulated in detail and the safety measures supposing the impact of the missile to certain ...
Implementation and Validation of an Advanced Hypoplastic Model for Granular Material Behavior
Montaser Bakroon, Reza Daryaei, Daniel Aubram, Frank Rackwitz, Chair of Soil Mechanics and Geotechnical Engineering, Technische Universität Berlin, Berlin, Germany
Problems in soil mechanics and geotechnical engineering are often characterized by large deformations and complex material behavior. For example, the mechanical behavior of granular materials like sand is highly nonlinear due to the presence of an evolving internal structure formed by the grains. The strength and stiffness is generally a function of the stress and density state and the loading history. While LS-DYNA® has proved to be among the ...
Implementation of MCEER TR 14-0006 Blast Load Curves in LS-DYNA® and Benchmark to Commonly Practiced Blast Loading Application Methods
Devon Wilson, Deborah Blass, and Sam Noli, Arup
A tool has been developed to explore implementation of the blast load curves derived by J. Shin, A. Whittaker, A. Aref and D. Cormie in the MCEER Technical Report 14-0006 (2014). The MCEER proposed blast load curves capture the effects of high explosives near the face of the charge, where the traditionally-used Kingery and Bulmash (KB) empirical data is not applicable. Although not a replacement for a proper computational fluid dynamics ...
Implementation of the Projected Subgradient Method in LS-TaSC™
Willem Roux, Imtiaz Gandikota, ivermore Software Technology Corporation;
Guilian Yi, Dalian Fukun Technology Corporation
The projected subgradient method is major new methodology development for the topology optimization of huge, multi-disciplinary structural problems; for example, the combined impact, statics, and NVH design of a whole body in white. This paper accordingly discusses the projected subgradient method in LS-TaSC, with specific reference to the basic theory, the ability to combined impact and NVH load cases, and the performance for huge models. Also ...
Improvement of Mesh Fusion in LS-DYNA®
Houfu Fan, Xinhai Zhu, Li Zhang, Yuzhong Xiao, Livermore Software and Technology Corporation
In this work, mesh fusion in MPP is successfully implemented in LS-DYNA. It has been demonstrated through benchmark examples that MPP mesh fusion can reduce the simulation time (25%) and make sure the accuracy (error within 2%) of the forming process. The result for the corresponding springback analysis is slightly large (error within 10%) and can serve as a rough and quick estimation.
In Core Adaptivity
Brian Wainscott, Houfu Fan, LSTC
Adaptivity is almost universally used in metal forming applications. As useful as it is, there are certain inefficiencies in its execution which are a result of the way in which it was implemented. The current approach requires a significant amount of I/O and code serialization. A new method is being developed in MPPDYNA which not only performs the adaptivity in parallel, but without exiting the solution loop. The current status of this work is ...
Increasing the Scale of LS-DYNA® Implicit Analysis
Jef Dawson, Ting-Ting Zhu, Cray;
Cleve Ashcraft, Roger Grimes, Robert Lucas, Francois-Henry Rouet, Livermore Software Technology Corporation;
Erman Guleryuz, Seid Koric, National Center for Supercomputing Applications;
James Ong, Rolls-Royce
Cray, LSTC, NCSA, and Rolls-Royce formed a partnership to explore the future of implicit computations as the scale of both finite element models and the systems they run on increase. Rolls-Royce created a family of dummy engine models, using solid elements, with as many as 200,000,000 degrees of freedom. NCSA ran these with specialized LS-DYNA variants, generated by Cray, on their Blue Waters machine, a hybrid Cray XE/XK system with 360,000 AMD ...
Influence of Side Windows Type on Occupants’ Injury Response in the Cutaway Bus Rollover Analyses
Grzegorz Dolzyk, MohammadReza Seyedi, Sungmoon Jung, Jerzy Wekezer, FAMU-FSU College of Engineering, 2525 Pottsdamer Street, Tallahassee, FL 32310-6046
In the rollover crash scenarios, occupants are often subjected to impact with interior parts of the bus, especially side windows which play the main role in ejection protection. In this study, we investigated the influence of the window’s glass type and their modeling techniques into occupants’ response during the rollover experiment. Rollover experiment of the cutaway bus was conducted in compliance with ECE R66, which is also known as a tilt ...
Investigating the Post Processing of LS-DYNA® in a Fully Immersive Workflow Environment
Ed Helwig, Facundo Del Pin, Livermore Software Technology Corporation, Livermore CA
The use of virtual reality (VR) in engineering applications has been expanding for the last decade. Immersive technology is quickly becoming a tool for pre and postproduction decision-making and analysis. Virtual reality can assist in reducing the number of physical prototypes, build collaboration between various engineering disciplines, speed up time to manufacturing, and reduce the number of design cycles. We examined the integration of ...
Investigation of the Failure Behavior of Bolted Connections under Crash Loads and a Novel Adaption to an Enhanced Abstracted Bolt Model
Florian Schauwecker, Daimler AG, Research and Development, Sindelfingen, Germany, IFB Institute of Aircraft Design, University of Stuttgart, Germany;
David Moncayo, Dr.-Ing. Markus Beck, Daimler AG, Research and Development, Sindelfingen, Germany;
Prof. Dr.-Ing. Peter Middendorf, IFB Institute of Aircraft Design, University of Stuttgart, Germany
This study presents a new approach for the modelling of bolted joints in vehicle crash simulations with LS-DYNA®. In order to evaluate energy absorption concepts, it is essential to transfer loads between joining parts and to predict the failure behavior of threaded fasteners. For conventional models, the maximum tensile strength or the maximum elongation is considered as a failure criteria. Enhanced bolt models require the comprehension of the ...
Latest FE Model Development of THOR-50M Crash Test Dummy
Ismail Maatouki, Humanetics Europe GmbH, Heidelberg, Germany;
Stephen Fu, Zaifei Zhou, Humanetics Innovative Solutions, Inc. Farmington Hills, MI (USA)
THOR-50M LS-DYNA® Finite Element (FE) dummy model, developed by Humanetics (Humanetics Innovative Solutions, Inc.), has been widely used in occupant safety by OEMs and suppliers and has proved to be a mature model since its first release in early 2014. In the next two years, major development work had been completed, including material characterization, component validations, sled test validations and robustness verifications.
Li-Ion Battery Modeling Strategies for Electric Vehicle Crash Applications
Matthieu Seulin, Charlotte Michel, Vincent Lapoujade, DynaS+, Toulouse, France;
Pierre L’Eplattenier, LSTC, Livermore, CA, USA
In the automotive field, car manufacturers currently face a revolution in terms of energy sources to power vehicles. The combination of electric engines and Li-Ion batteries is an efficient solution to solve environmental issues, and its usage is expected to grow in the future. Nevertheless, this technology may present some serious hazards which origins are different than the thermal engines ones. The Li-Ion batteries are generally located all ...
LS-DYNA® ALE Modeling of Blast in an Urban Environment
Sergey Medyanik, Michigan Engineering Services, LLC;
Syed Mohammad, Department of Homeland Security;
Nickolas Vlahopoulos, University of Michigan
In LS-DYNA finite element analysis software, Arbitrary Lagrangian Eulerian (ALE) approach can be applied to modeling dynamic loading due to explosives. The main advantage of this method is its good accuracy as it explicitly models the explosive and the pressure wave propagation through the media. However, this approach typically requires using very fine meshes in order to accurately model problems characterized by high peak pressures as mesh ...
LS-DYNA® Belted Occupant Model
Stephen Kang, Cong Chen, Manjeera Paladugu, Murugan Sundaram Ramasamy, Lalitha Gade, Ford Motor Company;
Sarba Guha, Livermore Software Technology Corporation;
Fuchun Zhu, Humanetics Innovative Solutions
The seat belt is one of the most critical components in automotive crash safety. The three-point belt system has been around for fifty-eight years, belt pretensioners for thirty years and retractor torsion bar load limiters for eighteen years. Though the belt system has been around for so long, CAE correlation to physical test is still limited and far from having high confidence predictive capability. There are numerous CAE parameters and all ...
LS-DYNA® Performance on Intel® Scalable Solutions
Nick Meng, Michael Strassmaier, James Erwin, Intel;
Jason Wang, LSTC
Along with the Intel® Purley platform launch, a series of cost-effective products such as the Intel® Xeon® processor Scalable Family (formerly code-named Skylake-SP), Intel® Omni-Path Architecture fabric, Intel® SSDs, Intel® MPI 2018 library, and Intel® Math Kernel Libraries (MKL) have been released in 2017. In this paper we study and evaluate the impact of these Intel products on LS-DYNA application. Numerous factors affect application ...
LS-DYNA’s Linear Solver Development — Phase 1: Element Validation
Allen T. Li, Ford Motor Company;
Zhe Cui, Yun Huang, Livermore Software Technology Corporation
LS-DYNA is a well-known multi-purpose explicit and implicit finite element code. It is mainly used to analyze the nonlinear response of structures. To answer increasing requests from users, LSTC is taking a big effort to develop and improve the linear solution capabilities in LS-DYNA. As part of this endeavor, a joint project was launched between Ford and LSTC to validate the linear solvers in LS-DYNA. In this project, a bunch of benchmark ...
LS-DYNA’s Linear Solver Development — Phase 2: Linear Solution Sequence
Allen T. Li, Ford Motor Company;
Zhe Cui, Yun Huang, Livermore Software Technology Corporation
This paper continues with the last one from the same authors on validating LS-DYNA’s linear solver development on elements (Phase1: Element Validation). In this paper, a simple plate model is used as the benchmark example for validation on linear solution sequence. The linear solutions from NASTRAN: SOL101 (static analysis), SOL103 (normal mode analysis), SOL108 (direct frequency response), SOL109 (direct transient response), SOL111 ...
LS-DYNA’s Linear Solver Development — Phase1: Element Validation Part II
Allen T. Li, Ford Motor Company;
Zhe Cui, Yun Huang, Livermore Software Technology Corporation
This paper continues with the last one from the same authors on validating LS-DYNA’s linear solver development on elements (Phase1: Element Validation Part I). In this paper, the R-type elements and bushing elements are investigated. The R-type elements include both rigid (RBE2, etc.) and interpolation elements (RBE3, etc.), which are very popularly used elements. The bushing (generalized spring and damper) elements consist of the CBUSH and ...