Study On The Seismic Response Of Unanchored Floating Roof Liquid-storage Tank With The Base Isolation

The liquid storage tank is the storage facility of the oils and a variety of chemicals,and it is important component of the petrochemical engineering device and the storage andtransportation system. Generally on account of inflammable、explosive and poisonousmedia keep in storage, the outcome is serious when the earthquake disaster coming up. Atthe same time, it is possible to occur fire、environmental pollution and the other secondarydisaster, which can cause a loss to production and national economy. Now thedevelopment tendency of the liquid storage tank is thin wall, base floating and largevolume. The large liquid storage-tank has floating roof, and the tank directly floating puton the base. Therefore, nowadays the problem of seismic isolation to the floating roofliquid storage tank which freely put on the base is one of the research hotspot.In this paper, Using ansys software establish liquid storage tank finite element modelwhich consider fluid-solid interaction, geometric large deformation, the liquid greatlyshaking, material nonlinear and state nonlinear and variable thickness of the tank. Theoutline of the dissertation is as follows:1、The finite element model of unanchored liquid-storage tank considering nonlinearcontact is built and its reliability is verified.2、Modal analysis is carried out on the liquid-storage tank with floating roof andliquid-storage tank without floating roof to verify the natural vibration properties of thesetwo kinds of tanks. The influence with natural vibration characteristics of floating roof onthe liquid-storage tank is analyzed.3、Seismic response analysis, based on the fluid sloshing and the uplift of tank bottom,is carried out on the liquid-storage tank with floating roof and liquid-storage tank withoutfloating roof. The influence with seismic response of floating roof on the liquid-storagetank is analyzed.4、Considering the same of isolation frequency, damping ratio, the isolation floating roof liquid-storage tank and liquid-storage tank without floating roof responded to seismicresponse is analyzed. It conclude radial displacement、circumferential tensile stress、axialcompressive stress and equivalent stress. The influence with damping effect of floatingroof on the liquid-storage tank is analyzed.