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.

当前，流体结构相互作用（FSI）问题的准确模拟在学术界仍然是一项艰巨的任务。这项工作的目的是开发一种三维（3D）耦合算法以达到最终效果，其中分别采用显式运动粒子模拟方法（MPS）和有限元方法（FEM）来考虑流体流动和结构形变。所开发的耦合算法继承了上述方法的优点，同时也解决了它们的缺点。我们首先将一个新提出的“鬼单元边界”（GCB）模型扩展到三个维度，该模型已被证明是处理复杂形状的壁边界的有效方法。对于感兴趣的问题，结构离散化的有限元充当了相互作用力计算的鬼单元，从而为构建鬼单元提供了一种简单而自然的方法。使用MPS模型的积分形式处理流体与结构之间的相互作用，并将在单元积分点上计算出的合成相互作用力分配给有限元节点，以便在明确的时间积分的情况下更新节点运动学方案。通过两个数值示例验证了3D GCB模型的有效性和准确性，即水坝破坏试验和旋转齿轮试验中的水流。然后，将开发的耦合算法应用于两个常见的FSI问题，即分别具有弹性障碍物和弹性闸门的溃坝试验。