A computer simulation methodology of metal perforation

In this paper, shear deformation at high strain rates is modelled with the framework of discrete dislocation plasticity. The total stress state is split into the stress state due to the dislocations in an infinite medium, and the complementary image stress, which is enforced by a finite element solution. Sources and obstacles are put into the material, and constitutive rules are implemented for the creation and annihilation of dislocations. High-velocity stress and displacement fields are used, as well as the Gillis-Gilman-Taylor drag relation. When the velocity of a dislocation approaches that of the local shear wave speed, the stress and displacement fields undergo a Lorentz-contraction in the direction of motion. The issue is addressed whether these local changes in stresses and displacements affect the overall stress-strain curves significantly. The dependence on temperature is briefly discussed.