Elastic-plastic collapse of super-elastic shock waves in face-centered-cubic solids

18th APS-SCCM; 24th AIRAPT

Zhakhovsky, Vasily V.^1 ; Inogamov, Nail A^2 ; Demaske, Brian J^1 ; Oleynik, Ivan I.^1 ; White, Carter T.^3

University of South Florida, 4202 East Fowler Avenue, Tampa

FL

33620-5700, United States^1

Landau Institute for Theoretical Physics, RAS, Chernogolovka, Russia^2

Naval Research Laboratory, Washington

DC

20375-5320, United States^3

关键词: Elastic state;    Elastic-Plastic;    Face-centered cubic;    Molecular dynamics simulations;    Moving window;    Piston velocity;    Pressure support;    Single-crystal Al;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/17/172007/pdf
DOI  :  10.1088/1742-6596/500/17/172007

来源: IOP

【 摘 要 】

Shock waves in the [110] and [111] directions of single-crystal Al samples were studied using molecular dynamics (MD) simulations. Piston-driven simulations were performed to investigate the split shock-wave regime. At low piston velocities, the material is compressed initially to a metastable over-compressed elastic state leading to a super-elastic single shock wave. This metastable elastic state later collapses to a plastic state resulting in the formation of a two-wave structure consisting of an elastic precursor followed by a slower plastic wave. The single two-zone elastic-plastic shock-wave regime appearing at higher piston velocities was studied using moving window MD. The plastic wave attains the same average speed as the elastic precursor to form a single two-zone shock wave. In this case, repeated collapse of the highly over-compressed elastic state near the plastic shock front produces ultrashort triangle pulses that provide the pressure support for the leading elastic precursor.