The paper deals with the analysis of reliability and safety of a welded tank for the storage of oil, which is located in the Czech Republic. The oil tank has a capacity of 125 thousand cubic meters. It is one of the largest tanks of its kind in the world. Safety is ensured by a steel outer intercepting shell and a double bottom. The tank was modelled in the programme ANSYS. The computational model was developed using the finite element method – elements SHELL181. A nonlinear contact problem was analysed for the simulation of the interaction between the bottom plate and foundation. The normative approach in design and check of tanks according to standards API 650, ČSN EN 14015, EEMUA 159 and API 653 is mentioned. The dominant loading of the filled tank is from oil. The normative solution is based on the shell theory, which considers constant wall thickness. For real tanks sheet thicknesses of individual courses increase with increasing depth. Stochastic sensitivity analysis was used to study the effect of the variability of the thickness of the ith course on the stress of adjacent courses. The Latin Hypercube Sampling method was implemented during analysis.

This article focuses on the reliability analysis of a welded cylindrical tank, which is used for the storage of crude oil. The dominant load case is loading of the inner shell by hydrostatic pressure of the crude oil. Stochastic sensitivity analysis was used to study the effect of the variability of the thickness of the ith course on the stress state of adjacent courses. The computational model was developed in the programme ANSYS. Meshing was performed using SHELL181 elements. The Latin Hypercube Sampling method was implemented during analysis. Sensitivity analysis based on the evaluation of the correlation between the random plate thicknesses and the stress state was performed.