A 3D h-adaptive local remeshing technique for simulating the initiation and propagation of cracks in ductile materials

Abstract

We propose an h-adaptive 3D FE methodology to represent the initiation and propagation of cracks in ductile materials. Element size is driven by size indicators based on values for the cumulative plastic strain and an appropriate measure of ductile damage. Cracks are represented as locations of all the fully damaged elements which are deleted from the mesh. The mesh is first refined locally with respect to the size map using a 3D bisection technique, and then it is optimized. The size of the loading sequence is adapted to control both the size and the number of the damaged elements to be deleted. We propose a hybrid FEM-Diffuse field transfer procedure devoted to highly localized physical fields (stress, damage, plastic strain). To test its effectiveness, we implemented this new 3D adaptive methodology in an ABAQUS/Explicit® solver, using modified quadratic tetrahedron elements (C3D10M). We provide 3D examples to show how the proposed approach is able to predict the initiation of damage and the propagation of macroscopic cracks inside plastic structures.