Nonlinear Seismic Response Analysis Of Liquid Storage Tanks Considering Liquid-solid Coupling

Liquid storage tanks are important industrial facilities for petroleum enterprises, petrochemical enterprises and other related enterprises to store the mediums with inflammable, explosive and toxic characteristics. Once destroyed under earthquake, the consequence of the disaster is very serious. Since the 1930s, extensive research has been conducted on cylindrical liquid storage tanks, however, these researches pays primary attention on the linear elastic behaviors and worldwide achievements are obtained, which could contribute to tanks engineering design. But the study on the real behavior of liquid storage tanks under earthquake and the nonlinear seismic response revealing the failure mechanism of tanks is very rare. In this paper, nonlinear seismic analysis method of cylinder type anchorage tanks considering the liquid-solid coupling is given. Furthermore, nonlinear seismic response of tanks and failure mechanism are studied. All these studies to guarantee the safety of liquid storage tanks and to reduce of earthquake disasters are of great importance.The main research and achievement are given as follows:1. The types of liquid storage tanks, failure modes of liquid storage tanks under earthquake are summarized systematically. The classical theory of storage tank which includes Housner theory for rigid liquid tank wall and Veletsos theory for flexible liquid tank wall is introduced briefly, the achievements in domestic and foreign on liquid storage tanks study and its developing trend is discussed.2. Using large finite element soft ADINA, nonlinear seismic response analysis of liquid-solid coupling tanks is realized. The liquid storage tanks wall elements and liquid elements are chosen, the interface elements are defined, the size of grid mesh requirement is discussed, the constitutive relationship of elastic-plastic material is determined, the liquid-solid coupling between liquid storage tank and liquid is implicated.3. The behaviors of non-linear seismic response of 1000m3 and 10000m3 liquid storage tanks under five different ground motions with different site conditions are researched. Through calculating the natural vibration characteristic of liquid storage tanks, change tendency of acceleration peak along tank wall, stress and strain distribution of tank wall, the influence on seismic response of liquid storage tanks from the size of liquid storage tanks, liquid height, site condition, acceleration peak are obtained. These results preliminarily reveal the failure mechanism and could provide the scientific references in engineering design.