COMPARISON BETWEEN DIRECT AND INDIRECT COUPLING FOR SEISMIC ANALYSIS OF FLUID-STRUCTURE COUPLED SYSTEM

The present paper deals with the analysis of the fluid–structure systems considering the coupled effect of elastic structure and fluid adjacent to it. Both fluid and structure are discretized and modeled by finite elements. In the governing equations, pressure for the fluid domain and displacement for the structure are considered as independent nodal variables. Two different methods namely, direct coupled and indirect iterative approach for the analysis of fluid-structure system has been carried out in this study. In direct coupled approach, the solution of the fluid-structure system are accomplished by considering these as a single system while in indirect iterative method, the responses are obtained by solving the two systems separately with enforcing the interaction effects at the interface. The results obtained from these two methods are compared in terms of CPU times to evaluate the effectiveness of these methods for varieties of fluid-structure interaction problems. The outcomes of the results show that the effectiveness of these methods mainly depends on the degree of flexibility of structure and the length of the reservoir adjacent to it.