Temperature and strain rate sensitivity of shocked aluminium: multiscale dislocation dynamics simulations

摘要

Multiscale dislocation dynamics plasticity (MDDP) simulations are carried out to investigate the mechanical response of aluminium single crystals subjected to extreme conditions of high strain rate over a wide range of temperatures. Atomistically informed generalised dislocation mobility law is integrated in MDDP and the effects of temperature and strain rate on the dynamic yield point are scrutinised. Additionally, pressure and temperature-dependent elastic properties are employed to better capture the shockwave characteristics under thermochemical extreme conditions. The simulation results reveal unusual thermal hardening effect along with strain rate hardening behaviour. Based on the simulations findings, physically-based constitutive equation for the dynamic yield strength is proposed.