Combination of DEM/FEM for Progressive Collapse Simulation of Domes Under Earthquake Action

Abstract

In this paper, a coupled DEM/FEM model is presented to overcome the disadvantages generated by individually using discrete element method (DEM) or finite element method (FEM). The model divides the domain into two independent parts: the DEM sub-domain and the FEM sub-domain. First, the governing equations of the coupled model are established according to the virtual work equation and variational principle, the formula of interface-coupled force is derived based on the penalty function method, and the corresponding program is coded. Second, the key problems involved in the coupled model are investigated, which are the selection of the penalty parameter, the determination of the time-step, and the formulation of the governing equations of the system in the DEM and FEM domains. Finally, the coupled model is applied to progressive collapse simulation of single-layer reticulated domes subjected to severe earthquakes. Both the collapse process and failure mechanism of the numerical results are consistent with the shaking table test phenomena, thereby verifying the validity of the coupled model proposed. The method proposed realizes the balance between computational efficiency and accuracy, that is, the small deformation region is simulated by FEM, while the DEM is applied to discretize the large deformation or failure region. Additionally, it is of high computational efficiency and of reliable precision.