3D atomistic simulation of fatigue behavior of a ductile crack in bcc iron loaded in mode II

We present new results of 3D molecular dynamic (MD) simulations of a mechanical response of an edge crack ( 1 ¯ 1 0 ) [1 1 0] (crack plane/crack front) in a single crystal of bcc iron cyclically loaded in mode II at room temperature and 0 K under different boundary conditions. Our previous 3D simulations showed this crack emitted blunting dislocations in the inclined 〈 1 1 ¯ 1 〉 { 1 ¯ 1 2 } slip systems under monotonic uniaxial tension loading in mode I and was stable up to very high loads. These findings were in qualitative agreement with experiments and continuum predictions. Our current study questions how the cyclic loading in mode II changes crack behavior and its stability. The paper also presents information on comparisons with fatigue behavior of the crack loaded in mode I and mode III.