3D analysis of failure modes in the Charpy impact test

A three-dimensional analysis of the Charpy V-notch specimen subject to impact loading is carried out, using a data parallel implementation in a transient three-dimensional finite element programme. An elastic-viscoplastic constitutive relation for a porous plastic solid is used to model ductile fracture by the nucleation and subsequent growth of voids to coalescence. Cleavage is modelled in terms of attaining a critical value of the maximum principal normal stress over a specified material volume. A convected coordinate Lagrangian formulation is employed and the discretization is based on twenty-node brick elements with 2*2*2 Gauss points. The equations of motion are integrated numerically by an explicit integration procedure using a lumped mass matrix. The predictions of the full three-dimensional calculations are compared with those of corresponding plane-strain analyses.