Molecular dynamics simulation of micro mechanisms in slip deformation theory of crystals

Based on the discussion that there should be a micromechanism that causes a macroscopic slip of monocrystal copper, molecular dynamics simulations with the analytical displacement field around a crack tip have been carried out. The result of the simulation shows that macroscopic shear slip in an f.c.c. monocrystal copper occurs as discrete time events. This is because cross-slips occur in many places in a material such that a macroscopic shear slip is blocked until some critical state of deformation. A macroscopic shear slip then occurs suddenly at the critical state in which the area of disordered atomic arrangement has stretched from one end of a crystal to the other end. The reason why macroscopic shear slips occur in the directions of the slip planes of a crystal is attributed to the fact that the areas of disordered atomic arrangement develop only along those directions.