Abstract
The deformation and stress fields near micro surface crack tip in α-iron were simulated by molecular dynamic method. In a low stress level, the stress fields simulated by molecular dynamics were resembled to the solution of linear fracture mechanics. Dislocations were emerged from crack tip and the stress at the crack tip decreased by a shielding effect of emitted dislocation from crack tip. Then, the crack tip has shown an geometric shape by slip deformation. This variation of shape of crack tip seemed to promote the shielding effect. From these results, the micro crack, under a plastic deformation condition, might not be accompanied with a singlar-like stress field, according to such circumstances.
