An explicit MPS/FEM coupling algorithm for three-dimensional fluid-structure interaction analysis

Currently, accurate simulations of fluid structure interaction (FSI) problems still remain a challenging task in the academic community. The purpose of this work is to develop a three-dimensional (3D) coupling algorithm to achieve the end, where the explicit moving particle simulation method (MPS) and the finite element method (FEM) are respectively employed to account for fluid flows and structural deformation. The developed coupling algorithm inherits the advantages of the aforementioned methods, while also addressing their shortcomings. We start by extending a newly proposed ghost cell boundary (GCB) model, which has proved to be an effective method to deal with the wall boundary of complicated shapes, to three dimensions. For the problems of interest, the finite elements for structural discretization serve as ghost cells for interaction force calculation, thereby providing an easy and natural way for the construction of ghost cells. The interactions between fluids and structures are dealt with using an integral version of the MPS model, and the resultant interaction forces calculated at integration points of a cell are distributed to finite element nodes for the update of nodal kinematics in the context of an explicit time integration scheme. The effectiveness and accuracy of the 3D GCB model are validated via two numerical examples, i.e., the dam break test and the water flow in a rotating gear test. Afterwards, the developed coupling algorithm is applied to two common FSI problems, i.e., the dam break tests with respective an elastic obstacle and an elastic gate. The good agreements between our simulation results and the existing data in literature demonstrate the accuracy and capacity of the developed coupling algorithm in solving FSI problems.