DEM-enriched contact approach for material point method

A major challenge for material point method (MPM) is to model multi-body and multi-material interactions. Prevailing contact schemes developed for MPM suffer from numerical instabilities, especially for the coexistence of multiple material boundary conditions. This study proposes a generalized contact scheme based on a hybrid scheme of MPM and discrete element method (DEM) to tackle such issues. The new scheme contains two novel features of particle–particle and particle–structure contact schemes guided by a DEM contact model to handle multi-material interactions. It leverages the advantages of both MPM and DEM, offering a unified way to flexibly handle either the boundary–particle or particle–particle multi-material interactions. Several typical physical processes are simulated to showcase the versatility of the proposed approach, including interface rotation and sliding, penetration, and granular material impact. It demonstrates that the generalized contact scheme can flexibly capture the mechanical responses of multi-body and multi-material systems in MPM.