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14th International LS-DYNA Conference

Detroit, 2016

Eigensolution Technology in LS-DYNA ®
Roger Grimes (LSTC)
LSTC has been adding additional eigensolution technology to LS-DYNA. For several years LS-DYNA has a Block Shift and Invert Lanczos Eigensolver in both SMP and MPP implementations. But this capability did not cover the full spectrum of applications. We have supplemented the Lanczos solver with a Power Method solver for Implicit mechanic problems using the Inertia Relief Feature. As we have been adding unsymmetric modeling features through ...
Evaluation of Various Numerical Methods in LS-DYNA ® for 3D Crack Propagation
Ala Tabiei, Wenlong Zhang (University of Cincinnati)
In this paper, four different numerical methods implemented in the large scale simulation code LS-DYNA ® are evaluated to determine their abilities and limitations in fracture problems especially 3-d crack propagation problems. These methods are: Finite Element Method (FEM), Discrete Element Method (DEM), Element Free Galerkin (EFG) method and Extended Finite Element Method (XFEM). Their methodologies are briefly described and several ...
Experimental and Numerical Investigation of the Tearing Resistance of a Parachute Woven Fabric using LS-Dyna ®
B.Perin, R.Blois, P.Bordenave (DGA Aeronautical Systems)
Ch.Espinosa (Université de Toulouse)
The performance of a parachute system is conditioned by its ability to sustain the loads applied by its environment during its life. Among others tear resistance is crucial since the unstable propagation of small defects into cracks can lead to the catastrophic loss of load carrying capacity. Defects under consideration are pre-existing notches or cuts. Experimental campaigns of quasi-static tear resistance in the warp and weft directions of ...
Finite Element Investigation of Injury Risks of Immature Pelvis and Femur in Pedestrian Impact
Ming Shen, Anil Kalra, Runzhou Zhou, Xin Jin, King H. Yang (Wayne State University)
Binhui Jiang (Hunan University)
Yajing Shu (Chongqing University)
Car-to-pedestrian collision is a major cause of injury and death for children. Due to the different anthropometric features of a child compared to an adult, children present more injuries in the pelvic region (including the proximal femur) than adults do. It was hypothesized that the epiphyseal growth plates (GPs) in the hip region may affect the stress distribution and further influence the injury pattern seen in children. To quantitatively ...
Frequency Domain Analysis for Isogeometric Element in LS-DYNA ®
Liping Li, Yun Huang, Zhe Cui (LSTC)
Stefan Hartmann (DYNAmore GmbH)
David J. Benson (Professor for Structural Engineering)
In the past few years numerous researches have been done in the area of Isogeometric Analysis (IGA), as the simulation model is exactly the desired geometry in this method. Frequency domain analysis is a cheap and fast alternative for time domain analysis. It is particularly suitable for vibration and acoustic analysis, which are very important topics for the design and research of automotives. This paper gives some frequency domain analysis for ...
Friction in LS-DYNA®: Experimental Characterization and Modeling Application
Sheng Dong, Marcelo Dapino (The Ohio State University)
Allen Sheldon, Kishore Pydimarry (Honda R&D Americas, Inc.)
Friction is a widely observed phenomenon in all engineering systems. The importance of friction in computer-aided engineering has long been overlooked and modeling of friction phenomenon has been oversimplified. This paper reports experimental work conducted on a pin-on-disc tribometer to characterize the coefficients of friction between various material combinations, and modeling work of using such measured coefficients in different CAE ...
Identifying Traumatic Brain Injury (TBI) Thresholds Using Animal and Human Finite Element Models Based on in-vivo Impact Test Data
Keegan Yates, Costin Untaroiu (Virginia Tech)
Traumatic brain injuries (TBIs) cause roughly 50,000 deaths per year in America. In order to lessen the severity or prevent TBIs, accurate dummy models, simulations, and injury risk metrics must be used. Human data is ideal to develop models, but injury conditions are often complex, e.g. primary and secondary impacts, and tissue level response can often only be studied via an autopsy, but death usually only occurs as the result of severe TBI. ...
Improvements for Implicit Linear Equation Solvers
Roger Grimes, Bob Lucas, Clement Weisbecker (LSTC)
Solving large sparse linear systems of equations is often the computational bottleneck for implicit calculations. LSTC is both continuously improving its existing solvers, and continuously looking for new technology. This talk addresses both, describing improvements to the default distributed memory linear solver used by LSTC as well as promising new research. We discuss improvements to the symbolic preprocessing that reduce the occurrences ...
Incorporation of Damage and Failure Into an Orthotropic Elasto-Plastic Three-Dimensional Model with Tabulated Input Suitable for Use in Composite Impact Problems
Robert K. Goldberg and Kelly S. Carney (NASA Glenn Research Center)
Paul Du Bois (George Mason University)
Canio Hoffarth, Bilal Khaled and Subramaniam Rajan (Arizona State University)
Gunther Blankenhorn (LSTC)
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, utilizes ...
Incorporation of Inconel-718 material test data into material model input parameters for *MAT_224
Stefano Dolci1, Kelly Carney1, Leyu Wang, Cing-Dao Kan (George Mason University)
Paul Du Bois (Consulting Engineer, Northville)
A research team from George Mason University, Ohio State University, NASA and FAA has developed material data and analytical modeling that allows for precise input of material data into LS-DYNA ® using tabulation and the *MAT_224 material model. The input parameters of this model are based on data from many experimental coupon tests including tension, compression, impact, shear and biaxial stress states. The material model also includes ...
Interactive Dynamic Analysis of Subsea Lifting Ropes
George Laird, Kirk Fraser (Predictive Engineering, Inc.)
Ryan Marsh (Sound Ocean Systems, Inc.)
The dynamic movement of subsea ropes presents an interesting numerical challenge due to the coupling of drag forces with the dynamic response of the rope. Although a FSI approach of fully coupling the surrounding seawater to the rope is theoretically possible it lies beyond the reach of practical engineering when discussing rope lengths in kilometers and possible rope movements in hundreds of meters. A new analysis technique is presented where ...
Introducing New Capabilities of JFOLD Version 3 and Airbag Folding Examples
Richard Taylor (Ove Arup & Partners International Limited)
Shingo Yagishita, Shinya Hayashi (JSOL Corporation)
A software tool called JFOLD has been developed by JSOL Corporation to enable successful airbag folding using LS-DYNA ® . This paper introduces some new capabilities of JFOLD Version 3 and demonstrates folding examples. JFOLD runs inside the powerful and popular pre-processor Primer. JFOLD Version 1 was released in July 2013 and has been continuously developed to make folding airbags quicker and easier.
Introduction of Rotor Dynamics using Implicit Method in LS-DYNA ®
Liping Li, Roger Grimes (LSTC)
Thomas Borrvall (DYNAmore Nordic AB)
Rotor dynamics is commonly used to analyze the behavior of structures ranging from jet engines and steam turbines to auto engines and computer disk drives. This paper introduces the implementation of rotor dynamics in LS-DYNA. The structural transient analysis and mode analysis and other applications, like brake squeal analysis, are presented and validated with other finite element software.
Jones-Wilkens-Lee (JWL) Equation of State with Afterburning
Leonard E Schwer (Schwer Engineering & Consulting Services)
The standard Jones-Wilkens-Lee equation-of-state for modeling detonation of high explosives was modified to allow inclusion of the additional energy associated with afterburning of fuel rich (oxygen poor) high explosives. Three options are available for including the additional afterburning energy: 1. Constant energy rate addition 2. Linear energy rate addition 3. Miller Extension The performance of the afterburning equation of state ...
Latest developments in Automotive Aerodynamics Using LS-DYNA ®
Iñaki Çaldichoury, Facundo Del Pin, Rodrigo Paz (LSTC)
LS-DYNA® is a general purpose explicit and implicit finite element program used to analyse the non-linear dynamic response of three-dimensional solids and fluids. It is developed by Livermore Software Technology Corporation (LSTC). A module to simulate incompressible flows has been added to LS-DYNA® for coupled fluid/mechanical/thermal simulations (ICFD solver). It offers a response to the ever increasing need of engineers in the automotive ...
Looping Formation During Colonoscopy A Simulation
Charles R. Welch, John D. Reid (University of Nebraska-Lincoln)
A simulation of a loop formation during colonoscopy is attempted using LS-DYNA . The tissue is comprised of a Mooney-Rivlin rubber model adjusted iteratively to somewhat match raw force-displacement data of small intestine tissue. After finding adequate parameters for friction and damping coefficients, the scope is advanced into a colon model in the simulation and loop formation appears. Whether the loop formation obtained through simulation is ...
Low Risk Deployment Passenger Airbag – CAE Applications & Strategy
Bill Feng (Jaguar Land Rover)
Occupants who were out-of-position (OOP) in the vehicles would increase the risk of airbag induced injuries in the crash event. The punch out forces resulting from the airbag deployment act on the occupant and would cause potential injuries. To evaluate the OOP performance of the airbag system, FMVSS208 requests a series of test loadcases. In passenger side OOP, it includes test loadcases with rear-facing child seats, 3yld and 6yld in ...
LS-DYNA ® Model Development of the Harmonized Hybrid III 05F Crash Test Dummy
Chirag S. Shah, George Hu, Jianying Li (Humanetics Innovative Solutions, Inc.)
Richard Barnes (Ford Motor Company)
Finite Element (FE) models of Anthropomorphic Test Device (ATD) commonly known as crash test dummies have become increasingly employed in automotive safety with the underlying benefits of cost and product development cycle. The current paper highlights the development of the harmonized Hybrid III 5th percentile (small female) dummy model referred hereafter as the “HH305 V1.0” LS-DYNA FE model. To be compliant with Euro NCAP test requirements, ...
LS-DYNA ® Peridynamics for Brittle Fracture Analysis
Bo Ren and C. T Wu (Livermore Software Technology Corporation)
E. Askari (Boeing Commercial Airplane)
Peridynamics is a new nonlocal theory that provides the ability to include displacement discontinuities in a continuum body without explicitly modelling the crack surface. In comparison to the classical weakly nonlocal or strictly nonlocal models, the peridynamics equation of motion is free of spatial derivative of displacement. The peridynamics also does not require sophisticated book keeping of degrees of freedom or jump conditions in ...
LS-DYNA ® Smoothed Particle Galerkin (SPG) Method with Strain Gradient Stabilization and Thermal Effects
Yong Guo, C.T. Wu, Wei Hu (LSTC)
The Smoothed Particle Galerkin (SPG) method in gradient form is presented and implemented in LS-DYNA for large inelastic deformation and material failure analyses from low to moderated high speed applications. The new formulation is established following a meshfree Galerkin approach for a solving of partial differential equation in solid mechanics problem and a Strain Gradient Stabilization (SGS) scheme is adopted in linear and ...
LS-DYNA ® Structured ALE (S-ALE) Solver
Hao Chen (LSTC)
A new Structured ALE solver is recently added into LS-DYNA. It targets to solve ALE problems with structured mesh. It supports all parallel versions of LS-DYNA, i.e., SMP, MPP and MPP Hybrid. The new solver generates structured ALE mesh automatically. The elements do not have to be of equal size. Instead, a user can define element spacing according to needs of the specific engineering problems. Listing all the elements and nodes used for ALE ...
LS-DYNA Performance Enhancement of Fan Blade Off Simulation on Cray XC40
Ting-Ting Zhu (Cray Inc.)
Jason Wang, Brian Wainscott (LSTC)
This work uses LS-DYNA to enhance the performance of engine FEA simulation of fan blade off containment test on Cray XC40 supercomputers. Blade off containment test is a specific form of air safety test required by the Federal Aviation Administration and other safety agencies, which involves the intentional release of a fan blade when engine is running at full power. The released blade must be contained within the fan cases during the impact ...
LS-OPT ® Status and Outlook
Nielen Stander and Anirban Basudhar (LSTC)
Features added to the recently released LS-OPT Version 5.2 are discussed. An outlook of the next version, which includes Statistical Classification and Digital Image Correlation, is given.
Material Testing for Development and Calibration of Material models for Plastic Deformation and Failure
Amos Gilat, Jeremy Seidt (The Ohio State University Department of Mechanical and Aerospace Engineering)
Material testing at various, loading conditions, temperatures, and strain rates is used forstudying plastic deformation and failure of materials. The data from such tests is used for developing and calibrating material model that are utilized in numerical codes that are used for simulations of practical applications. The presentation will review experimental techniques used in such testing with emphasis on the integration of Digital Image ...
Metal Forming Automation using LS-OPT ®
Krishna Chaitanya Kusupudi (Whirlpool Corporation)
The principal objective of this paper is to demonstrate the Metal Forming automation setup using LS-OPT, in which CREO (CAD software), Hypermesh (FE pre-processor), LS-DYNA ® (FE Solver) and LS-PrePost ® (FE post- processor) are integrated. Metal Forming simulations are performed to check the formability of an intended geometry for various process settings like different draw bead retention forces, friction coefficient, blank dimensions, ...
Model Set up and Analysis tools for Squeak and Rattle in LS-DYNA ®
Thanassis Fokilidis (BETA CAE Systems SA)
Jens Weber, Mehrdad Moridnejad (Volvo Cars)
One of the most important quality aspects during the design process of a vehicle is the provided occupant comfort. Comfort in a vehicle is achieved, among others, through a quiet and durable interior, and through the elimination of Squeak and Rattle noises. A huge amount of different tests take place in laboratories in order to produce interior and exterior components that eliminate the occurrence of such undesirable phenomena. As a result, ...
Modeling and Simulations of Vehicular Impacts on W-Beam Rail with Raised Blockouts
C. Silvestri Dobrovolny, N. Schulz, R.P. Bligh (Texas A&M Transportation Institute)
C. Lindsey (Texas Department of Transportation)
With recent changes about appropriate height for beam guardrail, there are more locations where rail height is below the recommended heights. Raising blockout on posts is a cost effective means to adjust rail height, however there is not any known analysis of how this might affects rail performance. The information compiled from this simulation study will enable the DOTs to decide whether raising wood blockouts on wood posts can be chosen as a ...
Modeling Crack Propagation in Rubber
Yoav Lev
Konstantin Volokh (Faculty of Civil and Environmental Engineering)
Traditional bulk failure models are based on the approach of continuum damage mechanics involving internal variables which are difficult to measure and interpret in simple physical terms. Alternative approach was proposed by Volokh [1-5], in which the function of the strain energy density was limited. The limiter enforces saturation – the failure energy – in the strain energy function, which indicates the maximum amount of energy that can be ...
Modeling Pre and Post Tensioned Concrete
Leonard E Schwer (Schwer Engineering & Consulting Services)
Modern concrete construction often uses pre-stressing of portions of the structure to improve the inherent tensile weakness of concrete. A compressive pre-stress is introduced into concrete using steel tendons loaded under tension. These tendons are either included in the concrete when the concrete is poured, i.e. pre-tension, or run through tubes that were cast in the concrete and then tensioned after the concrete is set, i.e. ...
Modeling Rebar in Reinforced Concrete for ALE Simulations
Shih Kwang Tay, Jiing Koon Poon, Roger Chan (Ministry of Home Affairs)
A constraint based method to couple rebar in reinforced concrete has been a popular method for Lagrangian simulations. However modeling rebar in Arbitrary Lagrangian-Euler (ALE) concrete has not been widely documented. This paper aims to investigate the effectiveness of the two constraint based keywords, *ALE_COUPLING_NODAL_CONSTRAINT and *CONSTRAINED_LAGRANGE_IN_SOLID found in LS-DYNA ® to couple beam elements in ALE concrete. This paper ...
Mullins Effect in Rubber Part Two: Biaxial
William W. Feng
John O. Hallquist (Livermore Software Technology Corp.)
The formulation, testing and numerical study of the Mullins effect on rubber are presented. To demonstrate the Mullins effect experimentally, a biaxial test, inflation of a plane circular membrane, is used. Some experimental test data are shown. An approximate solution, a relation between the inflation pressure and the displacement at the center for the inflation of a plane circular membrane is presented. The test data and the approximate ...
Multi-physics applications for ground vehicle aerodynamics: structural thermal radiation coupled to CFD for a more accurate temperature prediction
Facundo Del Pin, Art Shapiro, Iñaki Caldichoury, Rodrigo R. Paz, Julie Anton (LSTC)
Thermal radiation is an important heat transfer mechanism which may greatly influence the mechanical behavior of structural parts of a vehicle when they are exposed to aerodynamic loads. This effect is even more evident in high performance vehicles where the engines are running at ever higher temperatures and the structure is built using lighter parts with less conventional materials. The radiated heat from the engine or exhaust system will ...
Necking and Failure Simulation of Lead Material Using ALE and Mesh Free Methods in LS-DYNA ®
Sunao Tokura (Tokura Simulation Research)
After the Fukushima Daiichi nuclear disaster in 2011, the need of experiment to predict failure of the structures including pipes and vessels in nuclear power plant in case of large earthquake or tsunami has been increasing. However it is dangerous and expensive to perform such experiments using real structural material, e.g., 304 stainless steel as very large test facility is needed to cause realistic failure. Alternatively, the idea to use ...
New Conjugate-Heat Transfer Solvers in the Compressible CESE Solver in LS-DYNA ®
Grant O. Cook, Jr. and Zeng-Chan Zhang (Livermore Software Technology Corp.)
Standard coupling methods for performing conjugate-heat transfer between a compressible flow and a structural thermal solver have been previously implemented in the LS-DYNA Conservation Element/ Solution Element (CESE) compressible flow solvers. Unfortunately, they do not conserve energy. One consequence of this in conjugate- heat transfer calculations is that the CESE solver’s conservation properties are compromised by the errors in the ...
New XY-Plot interface in LS-PrePost ®
Philip Ho, Luo Liangfeng, Wenhui Yu, Satish Pathy (LSTC)
LS-PrePost, a pre and post processing program that compliments LS-DYNA ® , was lacking a good XY-Plotting tool. This paper illustrates and describes the new XY-PLOT which will make post-processing of results an efficient task. With the use of templates, plots from historical data can be generated quickly and compared with the current results. This paper discusses software architecture, its implementation and functionalities. It ...
Numerical Analysis of the Effects of Orthogonal Friction and Work Piece Misalignment during an AA5042 Cup Drawing Process
Allen G. Mackey (Rigid Packaging Division)
Wrinkle development during cup drawing operations is known to be highly dependent on many variables, including material anisotropy, tool geometry, process parameters, and tooling alignment. Weight reduction efforts in packaging industries have resulted in decreasing metal gauges, which exacerbates the formation of wrinkles. In this study, the Numisheet 2014 Benchmark 4 cup drawing process is used to investigate the effects of orthogonal ...
Numerical Study of an Interrupted Pulse Electromagnetic Expanding Ring Test
J. Imbert, M. Worswick (University of Waterloo)
Light weighting of vehicle structures will play an important part in the efforts to reduce fuel consumption and enable alternatively powered vehicles. The use of aluminum alloys and advanced high strength steels is one potential way of achieving significant weight reductions in the short to medium term. One of the main challenges posed by these materials is their relatively poor formability when compared with traditional automotive steel ...
Predictive fracture modelling in crashworthiness: A discussion of the limits of shell discretized structures
André Haufe, Filipe Andrade, Karl Schweizerhof (DYNAmore GmbH)
Markus Feucht (Daimler AG)
Herbert Klamser (Dr. Ing. h.c. F. Porsche AG)
Daniel Riemensperger (Adam Opel AG)
For many years shell formulations were used extensively in crashworthiness applications in order to predict deformations and even rupture of thin shell-like structures. From a general shell theory point of view there are probably no arguments to change this in the near future, unless none of the basic shell assumptions like using them for thin structures, having plane sections and only minor stresses in thickness direction, will be ...
Preference-based Topology Optimization of Body-in-white Structures for Crash and Static Loads
Nikola Aulig, Stefan Menzel (Honda Research Institute Europe GmbH)
Emily Nutwell (Ohio State University SIMCenter)
Duane Detwiler (Honda R&D Americas)
Topology optimization methods are increasingly applied tools for the design of lightweight structural concepts in the automotive design process. Ideally, topology optimization provides the optimum distribution of material within a user-defined design space for a given objective function. In the vehicle design process, two important objectives are to maximize stiffness of components for regular working conditions and to maximize energy absorption ...
Quasi-Static Simulations using Implicit LS-DYNA ®
Satish Pathy (LSTC)
Thomas Borrvall (DYNAmore Nordic AB)
Quasi-static tests that are part of the federal regulations such as FMVSS 216[1] and FMVSS 207/210[1] is predominantly simulated using LS-DYNA’s explicit solver. To be able to produce results in a reasonable time, mass-scaling and time-scaling are employed for these simulations, thereby the physics of the problem gets compromised. This paper demonstrates LS-DYNA’s Implicit capabilities to solve quasi-static problems in a reasonable amount of ...
Recent Advances on Higher Order 27-node Hexahedral Element in LS-DYNA ®
Hailong Teng (LSTC)
This paper presents recent advances of second-order hexahedral element developed for explicit/implicit analysis in LS-DYNA. Several benchmark problems are studied to demonstrate the performance of the higher order element. The results obtained in modeling practical applications involving large deformations, nearly incompressible materials, severe distortions, bending, and contact-impact are also encouraging. Compared to standard 8-node brick ...
Recent Development of ICFD Pre and Post Processing in LS-PrePost ®
Yu Wenhui, Zhang Zhanqun (Dalian Fukun Technology Corporation (China))
Philip W HO, Inaki Çaldichoury (LSTC)
As the usage of ICFD module of LS-DYNA grow widely, the requirements of Pre and Post processing dedicated to LS-DYNA ICFD module become more and more urgent. Since early 2014, we’ve been working on ICFD post processing module in LS-PrePost with LS-DYNA developers. It’s now available in LS-PrePost in version 4.3. This new ICFD post processing module is object-oriented, works in both 2D and 3D case. Currently, following functions ...
Recent Developments for Welding Simulations in LS-DYNA ® and LS-PrePost ®
Mikael Schill, Anders Jernberg (DYNAmore Nordic AB)
Thomas Klöppel (DYNAmore GmbH)
The multi-physics capabilities of LS-DYNA makes it ideal for simulating the welding process where the mechanical and thermal physical regimes are combined to simulate the resulting part tolerance and residual stresses. Welding capabilities are continuously being added to LS-DYNA, e.g. the material models *MAT_CWM and *MAT_CWM_THERMAL which are tailored for CWM simulations. The CWM material models include e.g. ghost element and anneal ...
Recent Updates for the Heat Transfer Solver in LS-DYNA ® with focus on computational welding mechanics
Thomas Klöppel (DYNAmore GmbH)
Mikael Schill (DYNAmore Nordic AB)
Tobias Loose (Ingenieurbüro Tobias Loose)
Even though welding is a well-established production process in manufacturing industries and it has a significant influence on the finished geometry as well as on the material properties of the processed part, it is still often ne- glected in the virtual process chain. In this contribution novel developments for the heat transfer solver in LS- DYNA ® are presented, which are designed to close this gap in the virtual process chain. First of ...
Robust Modelling and Validation Analysis on the Raffles City Chongqing Project
Zhi-Gang Liu, Shi-Chao Wu, Xiao Dong, Francois Lancelot, Li-Gang Zhu (Arup)
Since 2012, Arup has been providing structural engineering services for all design stages of the development of the Raffles City Chongqing (RCCQ). This truly iconic mega-complex has been designed by the internationally acclaimed architect Moshe Safdie for the developers CapitalLand and Singbridge Holdings. Various structural schemes for the 300m-long sky deck atop the four 250m-high interior towers have been assessed using LS-DYNA [1]. ...
Roof Rail Airbag Folding Technique in LS-PrePost ® Using DynFold Option
Vijay Chidamber Deshpande (GM India – Tech Center)
Wenyu Lian (General Motors Company)
Amit Nair (LSTC)
A requirement to reduce vehicle development timelines is making engineers strive to limit lead times in analytical simulations. Airbags play a crucial role in the passive safety crash analysis. Hence they need to be designed, developed and folded for CAE applications within a short span of time. Therefore a method/procedure to fold the airbag efficiently is of utmost importance. In this study the RRAB (Roof Rail AirBag) folding is carried ...
Saving Calculation Time for Electromagnetic/ Mechanical/Thermal Coupled Simulations by Using the New EM 2D/3D Capabilities.
Iñaki Çaldichoury, Pierre L‘Eplattenier (LSTC)
LS-DYNA ® is a general purpose explicit and implicit finite element program used to analyse the non-linear dynamic response of three-dimensional solids and fluids. It is developed by Livermore Software Technology Corporation (LSTC). An electromagnetism (EM) module has been added to LS-DYNA for coupled mechanical/thermal/electromagnetic simulations, which have been extensively performed and benchmarked against experimental results for ...
Sensitivity of Particle Size in Discrete Element Method to Particle Gas Method (DEM_PGM) Coupling in Underbody Blast Simulations
Venkatesh Babu, Kumar Kulkarni, Sanjay Kankanalapalli, Ravi Thyagarajan (RDECOM, TARDEC)
In this paper, the capability of two methods of modelling detonation of high explosives (HE) buried in soil viz., (1) coupled discrete element & particle gas methods (DEM-PGM) and (2) Arbitrary Lagrangian-Eulerian (ALE), are investigated. The ALE method of modeling the effects of buried charges in soil is well known and widely used in blast simulations today [6]. Due to high computational costs, inconsistent robustness and long run times, ...
Simulating Pellet and Clad Mechanical Interactions of Nuclear Fuel Rod for Pressure Water Reactors
W. Zhao, D. Mitchell, R. Oelrich (Westinghouse Electric Company LLC)
Pellet-cladding mechanical interaction (PCMI) is a potential failure mode leading to leaking fuel rods. Ever-increasing fuel duty and more demanding power maneuvers for adapting to alternative energy sources create new challenges for maintaining the high standard of fuel rod structural integrity. Towards meeting the new challenges, the paper describes an on-going effort in developing a coupled thermal-structural model suitable for simulating the ...
Simulation of Blast Load Reduction on Walls with Foamed Concrete Boards
Yijian Shi, PhD (ZASA - Logan, Zodiac Aerospace)
A foamed concrete board (FCB), often used as an insulation layer in structures, has been used to study blast attenuation. A LS-DYNA ® explicit solver chosen as a simulation tool reveals the physics of pressure waves, which transfer through materials, and internal stress in detail. The effectiveness of blast attenuation is measured by the reduction of peak pressure acting on a rigid wall (RW) that is immediately behind the FCB. According to ...