A simple prediction of the theoretical tensile strength of cubic crystalsbased on the shear strength calculations

摘要

This work presents a simple way how to estimate the uniaxial tensile strength on thernbasis of the theoretical shear strength calculations taking its dependence on superimposed normalrnstress into account. The atomistic simulations of the shear and tensile deformations in cubic crystalsrnare performed using first principles computational code based on pseudo-potentials and plane wavernbasis set. Six fcc crystals are subjected to shear deformations in convenient slip systems and arnspecial relaxation procedure controls the stress tensor. Obtained dependence of the ideal shearrnstrength on normal tensile stress seems to be almost linearly decreasing for all investigated crystals.rnTaking these results into account, the uniaxial tensile strength values in <110> and <111> directionsrnwere evaluated for selected fcc crystals.