Shock-induced spallation in single-crystalline tantalum at elevated temperatures through molecular dynamics modeling

The effects of initial temperature on shock-induced spalling behavior and damage evolution of single-crystal Tantalum were investigated using molecular dynamics simulation. The wave profiles show that shock pressure and temperature increment rise as initial temperature increases, which can be explained utilizing the RankineHugoniot relationship. It is found that strain rate and the initial temperature has a substantial effect on the spall strength. The spall strength will decrease with initial temperature increases, and the competition between the strain rate hardening and temperature softening effect on spall strength is discussed. The radial distribution function analysis reveal that the classical spallation occurs under shock velocity 1.5 km/s and micro-spalling state with material partially melted or melted happened in higher shock velocity. The simulations show that shock-induced spalling of Tantalum is characterized by void nucleation, growth, and coalescence. The void evolution characteristics in classical spallation and micro-spalling are discussed. Furthermore, it is found that the initial temperature has a dramatic effect on the void evolution. The total voids number increases as the initial temperature rises. The characteristics of the free surface velocity profile are also disscussed.