Molecular dynamics simulation of the interaction between cracks in single-crystal aluminum

The interaction between cracks, as well as their propagation, in single-crystal aluminum was simulated at the atomic scale by molecular dynamics method and modified embedded atom method. Further, the effects of the distance between two cracks and the difference of crack size on crack propagation and mechanical properties were comprehensively investigated. The results demonstrated that multi-crack propagation in aluminum is a quite complex process, which is accompanied by micro-crack growth, merging, stress shielding, and the crossing of slip bands. During crack propagation, there are interactions between cracks. Such interactions inhibit the phase transition, dislocation and slip bands at the crack tip, and also affect the direction of crack propagation. The intensity of the interaction between two cracks decreases with the increase of the distance between them and increases with increasing crack size. Moreover, the strength limit of aluminum decreases with the increase of the distance between cracks and the difference in their size.