LARGE-SCALE MOLECULAR-DYNAMICS SIMULATIONS OF FRACTURE GROWTH IN ALLOYS

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