Seismic response analysis models of an oil storage tank with a floating roof

Purpose - The purpose of this paper is to investigate the effects of the finite element models on the response of a free surface or a floating roof, which is important for safety assessment of oil storage tanks. Design/methodology/approach - Structural analyses of shell structures using the three-dimensional finite element method (FEM), potential flow analyses by FEM, and fluid-structure interaction analyses by strong coupling of the structural and fluid analyses were performed. In-house software was utilized for computations shown in this paper except the solver for non-symmetric sparse matrix. Findings - A model with a rigid tank and an elastic roof was confirmed to be able to perform the seismic response analysis most effectively from the viewpoint of computational cost with no reduction in accuracy. Research limitations/implications - The stress distribution on the floating roof will be evaluated to assess the safety of oil storage tanks subjected to seismic waves in the future research. Originality/value - This paper shows the dynamic responses of a liquid storage tank subjected to seismic motion using four different analysis models and the results were compared. It was concluded that a model with a rigid tank and an elastic roof can perform the seismic response analysis most effectively from the viewpoint of both accuracy and computational cost.