Fully Coupled Smoothed Particle Hydrodynamics-Finite Element Method Approach for Fluid–Structure Interaction Problems With Large Deflections

Abstract

In this study, a combination of the smoothed particle hydrodynamics (SPH) and finite element method (FEM) solving the complex problem of interaction between fluid with free surface and an elastic structure is studied. A brief description of SPH and FEM is presented. Contact mechanics is used for the coupling between fluid and structure, which are simulated with SPH and FEM, respectively. In the proposed method, to couple mesh-free and mesh-based methods, fluid and structure are solved together by a complete stiffness matrix instead of iterative predictive–corrective or master–slave methods. In addition, fully dynamic large-deformation analysis is carried out in FEM by taking into account mass and damping of the elastic structure. Accordingly, a two-dimensional fluid–structure interaction (FSI) code is developed and validated with two different experiments available in the literature. The results of the numerical method are in good agreement with the experiments. In addition, a novel laboratory experiment on a dam break problem with elastic gate in which the length of the initial water column is larger than its height is conducted. The main difference between the previous experiments and the one conducted in this study is that an upward water motion parallel to the elastic gate is observed at the upstream side of the gate. This motion is captured with the numerical method.

Investigation of the Sloshing Behavior Due to Seismic Excitations Considering Two-Way Coupling of the Fluid and the Structure

“…The velocity component in local tangential direction is zero and skin friction is not observed. Therefore, the parallel movement of an SPH particle is not disturbed [27].…”

“…At the beginning of the interaction, fluid particles were allowed to invade the structural domain, but these particles were expelled from the structural domain with the node to line equation of contact mechanics. The following equation developed for node to line contact mechanics was solved to represent the behavior of fluid and the structure under interaction [27]:…”

“…This parameter defines the depth of the boundary violation. The upper and lower limits of d is explained in [27]. Hydrodynamic variable of the relocated SPH particle should be modified according to its new position.…”

“…Various numerical models to couple fluid-structure interaction problems, such as MPS-FEM coupling [21] or immersed boundary methods combined with volume of fluid or level-set approaches [22][23][24], have been proposed in the literature [25]. In the present numerical model, smoothed particle hydrodynamics was coupled with the finite element method, and the coupling was satisfied with contact mechanics [26,27]. SPH, a Lagrangian and mesh-free method, was originally developed to simulate astrophysical problems [28,29].…”

“…The aim of the present study is to investigate sloshing due to the seismic excitations with the SPH-FEM method developed by the author [27]. The coupling of fluid and structure is satisfied with contact mechanics.…”