Numerical methods to improve the computing efficiency of discrete dislocation dynamics simulations

Dislocation dynamics (DD) is a method to simulate the collective dynamic behavior of dislocations and the plasticity of metals on a mesoscopic scale. A DD simulation is computationally demanding due to the fact that the stress field of a dislocation segment is long-ranged and it needs to examine a possible intersection between dislocation segments during their motion. The computing efficiency of a serial DD code is enhanced by using the so-called ‘box method’. The box method employing 213 boxes achieves 30-fold speed ups in the case involving 20,000 segments. The modified serial DD code has then been parallelized by using the standard message passing interface (MPI). Both the stress computation and handling segment intersection have been parallelized by using the domain decomposition method. Performance test on IBM p690 architecture shows that the parallel scheme adds up 20-fold speed ups when using 36 processors. Thus the parallel DD code presented here is about 600 times faster than the previous code. We present a parallel algorithm for highly complex dependencies in handling segment intersections and the performance test results in detail.