Explicit multi-time step computing method in the form of non-integer step ratio

Abstract

Due to the requirement of stability, the time step in explicit dynamics must be small enough. This inevitably leads to a waste of computing time to adopt a unified time step for dynamics models with partial refined mesh. Multi-time step or subcycling method especially the integer step ratio is a classical method to deal with these problems. An explicit non-integer ratio multi-time step computing method is proposed in this paper. The finite element model is divided into different subdomains by node partition and the coupling region is formed by multiple overlapping boundary nodes according to the step ratio between adjacent subdomains. Each subdomain chooses explicit integration time step according to mesh characteristics. Non-integer step ratio is used among adjacent subdomains. The method provides a new implement for explicit finite element analysis.