B-spline-based material point method with dynamic load balancing technique for large-scale simulation

In this study, a dynamic load-balancing (DLB) technique based on the sampling method is developed for MPMs using higher-order B-spline basis functions for parallel MPI calculations based on domain decomposition, in order to perform large-scale, long-duration landslide simulations in realistic computation time. Higher-order B-spline basis functions use a range of influence across cells compared to general basis functions, but this DLB technique dynamically adjusts the size of the computational domain according to the material point distribution, so that the material points are almost equally distributed across all cores. This allows the load bias between cores to be mitigated and the advantages of parallel computation to be fully exploited. Specifically, the novel contribution of this study is that the domain decomposition allows for proper communication between control points, even if the physical regions of the cores are staggered or non-adjacent, and even if the area of influence of B-spline basis functions spans multiple subdomains at this time. In numerical examples, the quasi-3D benchmark solid column collapse problem is computed for multiple core configurations to verify the effectiveness of the DLB method in terms of scalability and parallelization efficiency. The simulation of the full 3D column collapse problem also illustrates the applicability of the proposed DLB method to large-scale disaster simulations. Finally, to demonstrate the promise and capability of the DLB technique in the MPM algorithm, a full-scale size landslide disaster simulation is carried out to illustrate that it can withstand some practical size calculations.