Molecular dynamics simulations of interfacial crack nucleation and propagation

作者：Shang Fulin^*; Takayuki Kitamura

来源：Chinese Journal of Theoretical and Applied Mechanics, 2007, 39(4): 571-576.

• Cohesive energy
• Crack nucleation
• Interface crack
• Interface edge

Molecular dynamics (MD) simulations are carried out to study the critical conditions for crack nucleation at the interface edges and for crack propagation along the interface, and their relations. MD method is employed to examine the fracture behaviors near the apexes of the interface edges and near the tip of the interface crack, with the outer boundaries of the simulation cells being constrained by the elastic finite element displacement fields. The simulation results show that, at the instant of fracture initiation, the maximum stresses along the interfaces reach the ideal strength of the interface; also their interface energies can just overcome the intrinsic cohesive energy of the interface material. Therefore, the fracture conditions for crack nucleation at the interface edges and for crack propagation along the interface could be correlated through either the ideal strength or the cohesive energy of the interface. Further, a unified criterion for interface fracture initiation is proposed based on the simulation results.

• 出版日期2007