Skip over navigation

 

A Dynamic Discrete Dislocation Plasticity Method for Simulating Extremely High Strain Rate Plasticity

Beņat Gurrutxaga Lerma (Imperial College London), Daniel Balint (Imperial College London), Daniele Dini (Imperial College London), Daniel Eakins (Imperial College London), Adrian Sutton (Imperial College London)

Discrete Dislocation Plasticity

Tue 2:40 - 4:00

RI Hall 108

Traditionally, the study of plastic relaxation processes under weak shock loading and high strain rates in crystalline materials has been based on direct experimental measurement of the macroscopic response of the material. Using this data, well-known macroscopic constitutive laws and equations of state have been formulated. However, direct simulation of dislocations as the dynamic agents of plastic relaxation in those circumstances remains a challenge. Current Discrete Dislocation Plasticity methods, where dislocations are modeled as discrete discontinuities in an elastic continuum, are unable to adequately simulate plastic relaxation because they treat dislocation motion quasi-statically, thus neglecting the time-dependent nature of the elastic fields and assuming that they instantaneously acquire the shape and magnitude predicted by elastostatics. Under shock loading, this assumption leads to several artifacts that can only be overcome with a fully time-dependent formulation of the elastic fields. In this talk, a truly dynamic formulation for the creation, annihilation and arbitrary motion of straight edge dislocations will be presented. These solutions will be applied in a two-dimensional model of time-dependent plastic relaxation under shock loading, and some relevant results will be presented.