An adaptive hierarchical domain decomposition method for parallel contact dynamics simulations of granular materials

TL;DR

This paper introduces a fully parallel contact dynamics method for simulating granular materials, achieving high efficiency and stability through hierarchical domain decomposition and dynamic load balancing, suitable for large systems.

Contribution

It presents a novel fully parallel contact dynamics algorithm with hierarchical domain decomposition and dynamic load balancing, maintaining accuracy and stability for large-scale granular simulations.

Findings

Achieved 100% efficiency with up to 256 processors.

Parallelization does not affect simulation accuracy.

Convergence is maintained with negligible additional iterations at larger scales.

Abstract

A fully parallel version of the contact dynamics (CD) method is presented in this paper. For large enough systems, 100% efficiency has been demonstrated for up to 256 processors using a hierarchical domain decomposition with dynamic load balancing. The iterative scheme to calculate the contact forces is left domain-wise sequential, with data exchange after each iteration step, which ensures its stability. The number of additional iterations required for convergence by the partially parallel updates at the domain boundaries becomes negligible with increasing number of particles, which allows for an effective parallelization. Compared to the sequential implementation, we found no influence of the parallelization on simulation results.