Adaptive remeshing based on a posteriori error estimation for forging simulation

Abstract : This paper presents a fully automatic 3D adaptive remeshing procedure and its application to non-steady metal forming simulation. Remeshing, here, is considered as the improvement of an existing mesh rather than a complete rebuilding process. The mesh optimization technique is described. It is based on the combination of local improvement of the neighbourhood of nodes and edges. The surface and the volume remeshing are coupled by using a layer of virtual boundary elements. The mesh adaptation is performed by the optimization of the shape factor. The mesh size map enforcement is accounted for working in a locally transformed space. The size map is provided by a Zienkiewicz-Zhu type error estimator. Its accuracy is evaluated in the frame of a velocity/pressure formulation, viscoplastic constitutive equation and 3D linear tetrahedral elements, by numerical experiments. The adaptive remeshing procedure is applied to non-steady forging. Several complex 3D examples show the reliability of the proposed approach to automatically produce optimal meshes at a prescribed computational cost