Unified Calculation Method that Treats a Fluid as an Elastic Material Based on the Finite Element Method

Abstract

The analysis of fluid-structure interaction (FSI) is difficult since we need to couple different calculation methods along with complex boundary conditions. To overcome this problem, we propose a unified calculation method using almost the same governing equation for both fluid and elastic materials, based on the idea that fluid and elastic materials can be treated in the same way except that fluids cannot maintain shearing stress. By using the Newmark algorithm with the finite element method, we show that the numerical results of our simple method agree well with analytical results. Furthermore, from the principle of the Newmark algorithm, our method ensures unconditional stability for FSI calculations.