Buckling analysis of open-topped steel tanks under external pressure

Oil storage tanks are typically thin-walled structures which are susceptible to buckling under external load. This paper explores the buckling behavior of two in-services 100,000 m(3) open-topped tanks under external load by finite element simulation. The finite element analyses are first carried out to explore the stability of in-services tanks under the uniform external pressure and the wind load. And comparison with that three formulae which uses for calculating the critical buckling load of the tank under uniform external pressure. Then carried out the nonlinear buckling analysis by arc-length method, the results show that for in-services tanks, the linear elastic bifurcation analysis also is a good signal for the buckling load. Finally, this paper focus on the influence of wind girders and other reinforcement devices on the buckling behavior of in-services tanks and the strengthening mechanism of the stored liquid to in-service tanks with reinforcement devices. The reinforcement device affects the buckling behavior of the oil-storage tank by strengthening the stiffness of the top of the tank. However, the stored liquid through increasing the stiffness of the bottom of tanks to add the stability of tanks. And the result shows that compared to the oil-storage tank without reinforcement devices. The strengthening effect of the liquid on the tank containing reinforcement devices is more significant.