Buckling of Tanks With a Conical Roof Under Harmonic Settlement

Buckling behavior of tanks with a conical roof under harmonic settlement has been researched in this paper. A real tank in engineering is taken into account and the harmonic settlement is applied to the bottom of the tank to simulate its buckling behavior. Results show that the tank wall will be subjected to a deformation mutation when the settlement reaches a critical value. It means that compared to the conical roof, the tank wall is more vulnerable to buckling. Because of the complexity added by the grid of rafters and rings on the roof, two different simplified models are presented. For the first model, the tank’s roof is modified to an equivalent thickness based on the smeared method; for the other one, the roof is completely eliminated and its influence is represented by simply supported boundary conditions at the top of the tank wall. Analysis shows that the tank model without a roof can’t reflect buckling behavior of the real tank in engineering very well. While the model with an equivalent thickness roof can avoid this deficiency and achieve high efficiency and accuracy. It’s recommended to be applied to buckling analysis of tanks under settlement. Based on that, effects of wave numbers on the critical settlement for the three models are researched and compared. Result shows that the simplified tank model with an equivalent thickness roof presented in this paper is efficient and useful for buckling analysis of tanks with a conical roof under settlement.