Surface roughness evolution under constant amplitude fatigue loading using crystal plasticity

Crystallographic plasticity has been applied to study the initiation of microcracks on the smooth surface of polycrystals under a uniform applied stress. Even under a uniform external stress, due to the different crystallographic orientations of the grains in the polycrystals, there is non-uniform stress distribution and the deformation is also not uniform. Under the fatigue loading, the roughness increases with the number of fatigue cycles, and deformation will localize in some places, where microcracks form.