Atomic insights into the quasi-elastic response in shock reloading of shocked metals

• Published in: Results in physics 2021-12, Vol.31, p.104954, Article 104954
• Main Authors: Wang, Shengtao, Pan, Hao, Wang, Xi, Yin, Jianwei, Hu, Xiaomian, Xu, Wei, Wang, Pei
• Format: Article
• Language: English
• Subjects: Micro-mechanisms; Quasi-elastic response; Reloading; Shock compression
• ISSN: 2211-3797; 2211-3797
• DOI: 10.1016/j.rinp.2021.104954

•Heterogeneous shear stress is revealed for quasi-elastic re-shocked compression.•Local dislocation motion is reported for quasi-elastic behavior of shocked metals.•Inhomogeneous evolution of shear stress is crucial to quasi-elastic behavior. The quasi-elastic response has drawn much attention as an interesting phenomenon in physics of shock wave. It has been revealed that heterogeneity features such as defects on the mesoscale play important roles in the quasi-elastic response of shocked metals. In this work, we show heterogeneities on the microscale including distribution and evolution of the shear stress and dislocation structures in the re-shock compression of shocked metals. Molecular dynamics simulations on the copper single crystal show that the inhomogeneous characteristics evolves in the relaxation after the first shock compression, and leads to local dislocation motions among the stable global dislocation networks in the initial re-shock compression. Besides, the local dislocation motions are asynchronous upon the re-shock compression, which improves the local plastic deformation in the global elastic stage of the samples. In general, this work shows an atomistic picture about the re-shock compression of shocked metals, which includes different shear stress state and asynchrony mechanical response of the different local sites in the re-shock compression. These heterogeneities lead to combined deformation states in the re-compression of the shocked metals, which could be important micro-mechanism of the quasi-elastic response of shocked metals.