A Moving Element Method for Hydroelastic Response of a Floating Thin Plate Due to a Moving Load

Abstract

In this paper, the moving element method (MEM) is extended to cooperate with the boundary element method (BEM), namely, the BEM-MEM. This method is applied to compute hydroelastic responses of a pontoon type very large floating structure (VLFS) under wave action and also subjected to a moving load. By using this method, the structure is discretized into “moving elements” which are conceptual elements and “flow” with the moving load. Thus, the proposed method eliminates the need for keeping track of the location of the moving load with respect to the floating structure. The surrounding fluid is defined based on the potential flow theory and the motion of the floating plate is governed by the vibration equation of a thin plate. The governing equations of motion, as well as structural matrices of moving element and fluid matrices of boundary element are formulated in a relative coordinate system traveling at a constant speed. The numerical results conducted by using the BEM-MEM are compared with the results obtained by alternative approaches. The paper also discusses the effect of water depth on responses of the floating structure including displacements and drag force.