Simulating Dynamic Thermo-ElastoPlasticity in large Transformations with Adaptive Refinement in the NEM. Application to Shear Banding
Simulation of forming processes usually involves large transformations and/or stain localization. In the context of the finite element method (FEM), a common approach to deal with such phenomena is the use of continuous adaptive remeshing. Nevertheless, constructing a quality mesh is a delicate task, especially for complex 3D problems. The natural element meshfree method is a recent numerical technique which uses the features of the Delaunay triangulation of the set of nodes, providing an accuracy equivalent to the quadrilateral/hexahedral finite elements, even if the Delaunay triangles are very distorted. In this context, inserting or removing nodes is an easy task, as no special geometrical criterion is imposed on the relative position of the nodes. Furthermore, the use of a stabilized conforming nodal integration allows to define nodal internal variables, which simplifies transfer of these data through successive updates of the reference configuration in a Lagrangian procedure. In this paper, a framework for practical implementation of the NEM in the context of explicit thermo-elasto-plasticity at finite strains is provided, and an adaptive strategy, based on the attractive features of the NEM is developped. The proposed technique for forming processes simulation is illustrated in the context of dynamic shear bands propagation after impact.
Julien YVONNET, Philippe LORONG, David RYCKELYNCK, Francisco CHINESTA
Natural Element Method, Dynamic Thermo-Elasto-Plasticity, Large Transformations, Adaptive Refinement, Shear Bands.