Elastic‐viscoplastic implicit formulation for finite element simulation of complex sheet forming processes

Abstract

AbstractA formulation for numerical simulation of complex forming processes with generally shaped tools is developed. Special attention is drawn to the accuracy, efficiency and robustness. An incremental displacement approach based on Lagrangian formulation as well as an elastic‐viscoplastic material model with Hill's cross‐anisotropy, power law hardening and strain rate sensitivity are assumed. An implicit integration of the constitutive equations is derived. Frictional contact conditions yield additional constraint relations which, together with equilibrium equations, form the basis for derivation of the consistent tangent matrix. To further increase efficiency and accuracy, application of the adaptive remeshing procedures for sheet forming is investigated. The performance of the proposed algorithm is shown by comparison of the numerical results with the analytical solution for an in‐plane stretching test and with the experimental measurements from 3‐D sheet forming pressings where materials, radius and wall dimensions used are similar to those from industrial applications.