Propagation of stress wave in nickel single crystals nanofilm with cavity via molecular dynamics

Abstract

In order to investigate the propagation of the stress wave in nickel single crystals nano-film using molecular dynamics, firstly we study the propagation of stress wave in the nickel single crystals nano-film without and with semi-cylinder cavity. Secondly, we research the propagation of stress wave in the nano-film with cavity as the molecule number forming the cavity is same, but the shape of the cavity is different. The shear stress is loaded along x-axis, which is the 0.36Gpa square pulse shear stress and can be maintained 1ps. The simulation result shows that the stress wave does not vanish, which oscillates with a period in the nano-film as the impulse shear stress dies away. The stress values superimpose to give double peak value on the fixed end, and which is reversal on the free end. The effect of cavity on the propagation of stress wave is important. The stress value in the nano-film increases as the cavity size increases. The magnitude of addition stress wave caused by the cavity increases with the cavity size increases, when the shape of cavity is same. With the measure increasing along the direction that the external shear stress is loaded, the addition stress wave value increases even if the molecule number forming cavity is same. As the measure along the direction of the stress wave propagation increases, the lasting time that the stress wave is on each layer is affected intensively. The effect of square cavity on the propagation of stress wave is more than that of the semi-cylinder cavity.