Computational Modelling for Materials with Crystalline Structure : Molecular Dynamic Simulation of Microscopic Crack Tip Field under Antiplane Shear Loading

概要

論文の詳細を見る
The atomic-scale changes of a structure around the crack tip in an FCC crystal under antiplane shear loading are analyzed by molecular dynamics (MD) simulation. The interatomic force interaction is assumed to be derived from the many-body potential proposed by Ackland, G. J. et al. [Philos. Mag. A., 56-6(1987), p. 735]. The crack surface and its front are assigned to (1) [110] (001), (2) [110] (111), and (3) [110] (110). The fixed boundary condition is adopted, that is, the displacement of the atoms located at the boundary is given, so that the atomic block is embedded in the elastic singular field with the prescribed stress intensity factor K-<III>. Ductile deformation due to the emissions of screw dislocations from the crack tip is observed in every case. The dislocation moves in the {111} slip plane and dissociates into two Shockley partial dislocations. Repulsion between dislocations prevents their movement, and the so-called cross slip appears ; that is, some dislocations change their slip plane. Good correspondence is shown between the MD simulation and the results obtained from a continuum model of the crystalline material given by Rice and Nikolic [J. Mech. Phys. Solids. , 33-6, (1985), p. 595].
一般社団法人日本機械学会の論文
1995-01-15