Shear fracture of confined NaCl nanofilms

Abstract

Molecular Dynamic (MD) simulation was employed to study the mechanism of shear fracture in confined brittle NaCl crystal films. Six different representative volume elements (RVEs) were developed from single crystal NaCl. Two different crystal orientations were considered. Uniform shear displacements were applied to the confining rigid atoms. Crack was created at the center of each RVE by removing few atoms from the perfect crystal. For any RVE, the applied shear deformation causes the crack to propagate and initiates the fracture process. For any orientation and any degree of confinements, crack kinking was observed. The mode of crack propagation, however, was found to be heavily crystal orientation dependent. For each model, failure strain, stress and stress intensity factor were calculated. It is found that as the height/crack length ratio decreases, the fracture strength against shear loading increases.