2D adaptive FEM simulation of failures in high-speed impacts

The simulation of high-speed impacts needs the use of advanced constitutive equations required for the accurate prediction of the different thermomechanical fields and their mutual interactions (temperature, large strains, hardening, damage, friction …). Since these fields localize inside intense shear bands (ISB), ductile micro-cracks initiate inside these ISB leading to the initiation of macroscopic crack and its fast propagation until the final fracture occurs. Accordingly, these advanced constitutive equations should take into account not only the strong thermomechanical coupling but also the ductile damage and its strong effect (coupling) on the other thermomechanical fields. In this work a complete set of advanced and fully coupled thermo-elasto-viscoplastic-damage constitutive equations accounting for mixed nonlinear isotropic and kinematic hardening fully coupled with the ductile isotropic damage and the thermal softening for time dependent finite plasticity is presented. Related numerical aspects in the framework of a fully adaptive 2D finite element strategy are developed and briefly discussed. This adaptive procedure is applied to the simulation of simple high velocity impact of thick sheets with dynamic ductile fracture occurrence. Attention is paid to the localization of the main thermomechanical fields inside the ISB as well as to the macroscopic cracks initiation and growth under high velocity impact

Numerical prediction of thermomechanical field localization in orthogonal cutting

International audienc

2D adaptive FEM simulation of failures in high-speed impacts

The simulation of high-speed impacts needs the use of advanced constitutive equations required for the accurate prediction of the different thermomechanical fields and their mutual interactions (temperature, large strains, hardening, damage, friction …). Since these fields localize inside intense shear bands (ISB), ductile micro-cracks initiate inside these ISB leading to the initiation of macroscopic crack and its fast propagation until the final fracture occurs. Accordingly, these advanced constitutive equations should take into account not only the strong thermomechanical coupling but also the ductile damage and its strong effect (coupling) on the other thermomechanical fields. In this work a complete set of advanced and fully coupled thermo-elasto-viscoplastic-damage constitutive equations accounting for mixed nonlinear isotropic and kinematic hardening fully coupled with the ductile isotropic damage and the thermal softening for time dependent finite plasticity is presented. Related numerical aspects in the framework of a fully adaptive 2D finite element strategy are developed and briefly discussed. This adaptive procedure is applied to the simulation of simple high velocity impact of thick sheets with dynamic ductile fracture occurrence. Attention is paid to the localization of the main thermomechanical fields inside the ISB as well as to the macroscopic cracks initiation and growth under high velocity impact

Fuji, les mutants

National audienc

Fuji, les mutants

National audienc