3-D Domain Decomposition Method With Nonconformal Meshes for Thermoelastic Modeling

A 3-D domain decomposition method (DDM) with nonconforming meshes, based on the discontinuous Galerkin spectral element time-domain (DG-SETD) algorithm, is first extended for thermoelastic large-scale and multiscale modeling. This method is based on second-order elastic wave equation and considers various temperature-dependent material properties under multiscale temperature distributions. Additionally, a hybrid explicit-implicit time-stepping scheme is incorporated into the DDM to facilitate large-scale and multiscale efficient computations. For subdomains with fine structures or large thermal gradients and therefore fine meshes, an implicit scheme is adopted to obtain unconditionally stable time step increment. For subdomains with coarse meshes, an explicit scheme is employed and the time step increment is limited by the Courant−Friedrichs−Lewy (CFL) stability condition. Furthermore, a thin layer equivalent (TLE) method for fracture modeling is introduced to enhance the multiscale computational efficiency of our algorithm. The numerical results show that, compared with commercial software COMSOL, our algorithm achieves an accuracy exceeding 95% and an efficiency surpassing three times, demonstrating the higher performance of the DG-SETD algorithm.