A Study on Effect of Fluid on the Modal Characteristics of Ground Supported Water Tanks

Abstract

Liquid storage tanks are one of the essential lifeline structures which should function even after natural disasters. Water tanks in particular are essential for proper supply of water in the affected areas and for fire-fighting purposes. Sloshing is an important phenomenon occurring in partially filled tank with free surface. It can cause violent liquid motions that can cause instability in carrier-vessel and structural damage in the tank walls. To maintain the structural integrity of the carrier vessels, modal characteristics should be known as the impact of sloshing will increase when the excitation frequency matches with the natural frequency of container and result in resonant condition. This study investigates the modal characteristics such as natural frequency, mode shapes of square tank by 3-D finite element method using ANSYS 2019 R1software. The effect of impulsive and convective frequency of tanks with different fill levels and different boundary conditions are considered.