Asynchronous/multiple Time Integrators for Multi- Fracturing Solids and Discrete Systems

The current work presents an asynchronous/multiply time stepping integration scheme for the simulation of dynamic systems exhibiting multi-fracture and discrete features. It is a novel extension of existing methodologies to the discrete element simulation and several fundamental developments in both theoretical and implementation aspects are achieved that are essential for the success of the approach. It is shown that the resulting AVI/MTS discrete element method can achieve a nearly optimal speed-up for typical discrete systems. However, the stability is the issue that needs to be further addressed.