This article describes a detailed computational investigation and some prior experimental work of a large, elevated initial liquefaction tank and its associated support structure. Because the tank holds a high-density liquid and is subjected to very high dynamic loads, it is important to properly assess the structural integrity and adequate design for the tank and its supporting structures. The assessment is accomplished using finite element modelling (FEM) using ANSYS, reviewing the tank shell, tank base, and support columns under combined hydrostatic and seismic loads. The model also includes the effects of fluid-structure interaction (FSI), which allows it to more accurately reflect the system's complex dynamics. The results demonstrate that the largest stresses and deformations occur at the main support columns and at the junction between the tank bottom cone and tank shell. The results of this research also demonstrate that the typical approach to designing static structures (such as support structures) does not adequately characterise dynamic stresses in large structures, and the need to use a non-linear analysis approach for the dynamic evaluation of supporting structures. Based upon the outcomes of this research study, several recommended structural optimisations are provided that include modification of the support thickness and strengthening the connections to prevent buckling of the vessel and reduce long-term fatigue.
Karhad et al. (Sun,) studied this question.