F.E. elastoplastic damage model with 2D adaptive remeshing procedure for fracture prediction in metal forming simulation

In this work, an anisotropic elastoplastic finite element model strongly coupled with ductile damage is applied to simulate some metal forming tests used by Arcelor Research. The F.E. code is linked to a 2D adaptive remeshing procedure. First, the anisotropic elastoplastic model with non linear kinematic and isotropic hardening strongly coupled with ductile damage is presented. This model is written in finite plastic deformation through the so called rotated frame formulation using a non associative plasticity assumption with state variables. The adaptive analysis including the 2D mesh adaptation together with adaptive loading sequences and fully damaged elements deletion is described. This 2D adaptive procedure is applied to some metal forming tests with various high properties steel materials as the hole blanking and expansion. Two different cases are performed: (i) an initial hole is expanded starting from the zero stress at virgin state; (ii) the hole is first formed by blanking operation followed by the expansion process taking into account the residual fields (stress, strain, damage).