An Explicit-Implicit Mixed Staggered Asynchronous Step Integration Algorithm in Structural Dynamics

Many engineering applications need to analyse the system dynamics on the macro and micro level, which results in a larger computational effort. An explicit-implicit asynchronous step algorithm is introduced to solve the structural dynamics in multi-scale both the space domain and time domain. The discrete FEA model is partitioned into explicit and implicit parts using the nodal partition method. Multiple boundary node method is adopted to handle the interface coupled problem. In coupled region, the implicit Newmark coupled with an explicit predictor corrector Newmark whose predictive wave propagates into the implicit mesh. During the explicit subcycling process, the variables of boundary nodes are solved directly by dynamics equilibrium equation. The dissipation energy is dynamically determined in accordance with the energy balance checking. A cantilever beam and a building two numerical examples are proposed to verify that the method can greatly reduce the computing time while maintaining a high accuracy.