Large-scale molecular dynamics simulations of fracture growth in alloys

A two-dimensional grid containing over 100 000 atoms is used to simulate high strain rate growth in a Cu-Ni Monel alloy. Interatomic interactions are modeled by an appropriate Lennard-Jones potential with spline cut-off. A starter notch is introduced in a quenched sample, an external expansion is imposed, and crack initiation and propagation are demonstrated. The code is developed in Fortran-90 for usage on massively parallel computers and actual simulations are performed on a MasPar MP-1. The atomic positions are spatially decomposed on each processor, data are shared with adjacent processors, and atoms are transfered as they move.