Aseismic reliability analysis for oil storage tanks with random geometric initial imperfections

Here, random initial imperfection configuration of an oil storage tank was modeled with a linear combination of its buckling modes, and the imperfection amplitude was assumed to be a normal random distribution with mean of zero. Geometric initial imperfection samples were generated with Latin hypercube sampling method. Then, the incremental dynamic analysis method was employed to obtain the relation between the peak of acceleration and the maximum radial displacement of the tank wall, and according to Budiansky-Roth criterion, the critical buckling stress of the tank wall was determined under the action of earthquake. Furthermore, a user-defined subroutine based on ABAQUS was used to realize seismic response analysis of the imperfect oil storage tank with the added mass method. Finally, the reliabilities of the oil storage tank considering geometric initial imperfections and not considering them under the action of random earthquake were solved. The contrastive analysis showed that with increase in seismic action, the dispersion degree of the maximum compression stress of the tank wall increases; its probability distribution exhibits non-normal characteristics; the random geometric initial imperfections significantly reduce the aseismic reliability of oil storage tanks. © 2018, Editorial Office of Journal of Vibration and Shock. All right reserved.