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Accuracy Issues in the Simulation of Quasi-Static Experiments for the Purpose of Mesh Regularization

by Paul Du Bois5,676 views

Generating a LS-DYNA material model from cupon-level quasi-static experimental data, developing appropriate failure characteristics, and scaling these characteristics to mesh sizes appropriate for a variety of simulation models requires a regularization procedure. During an Investigation of an anisotropic material model for extruded aluminum, numerical accuracy issues led to unrealistic mesh regularization curves and non-physical simulation behavior. Sensitivity problems due to constitutive material behavior, small mesh sizes, single precision simulations, and simulated test velocity all contributed to these accuracy issues. Detailed analysis into the sources of innaccuracy led to the conclusion that in certain cases, double precision simulations are necesscary for accurate material characterization and mesh regularization.

Anthony Smith, Paul Du Bois

Aerospace and DefenseAutomotiveExtrusionLS-DYNAMechanicalMetalsNonlinear Material ModelsResearch PapersYielding/Failure Analysis

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Paul Du Bois

Paul Du Bois has worked as an independent consultant in the field of industrial application of large scale numerical simulations since September 1987. He has specialized in the application of explicit integration techniques for crashworthiness and impact problems.

Among Paul’s customers are most of the world’s automotive assemblers such as Daimler, GM, Ford, Opel, Fiat, Porsche, Volvo, PSA, Renault, Toyota, Nissan, Honda, Hyundai and many others including automotive suppliers and design and engineering companies. Paul’s more recent projects include a Daimler sponsored development of a generalized plasticity law for the simulation of plastics and the formulation of a tabulated hyper-elastic material law with damage for the simulation of rubber and foam.

He was involved with the joint research organization of the German automotive industry, FAT, in the working groups: ‘Side Impact Dummies’ from 1992 through 1997 and ‘Foam Materials’ (1996 until 2009). In 2003, Paul was asked by LSTC to perform a training mission at the Russian national laboratory in Snezinskh.

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