Molecular dynamics investigations of elastic-plastic properties of solids

Abstract
Classical molecular dynamics has been applied to investigations into elastic-plastic properties of solids. The investigations include behaviour of polycrystalline samples under shock loading. Dependence of the dynamic yield stress upon intensity of the shock loading and the mechanisms of the shear stress relaxation in nanocrystalline materials have been investigated. Another series of calculations refers to investigation into a material behaviour under stretching strain. It has been found that the initial stage of the fracture is the nucleation of vacancies in the form of spherical voids despite of one-dimensional character of the motion. Fusion of the voids results in formation of a crack. In the case of polycrystalline samples the centers of the nucleation lay on grain boundaries whereas in the case of monocrystalline sample the centers are positioned at the intersections of stacking faults created by shock waves.