Abstract
The study is aimed at analysis of the stability of thin-walled cylindrical shells under the action of external pressure, taking into account the initial imperfections caused by corrosion. Using the example of a shell with the following geometric parameters, L = 1000 mm, R = 500 mm, and h = 5 mm, comparison of solutions of linear and nonlinear numerical simulation of buckling using the Patran–Nastran software package has been performed. It has been shown that the critical pressure calculated using the formula of R. von Mises ( \({{q}_{{{\text{cr}}}}} = 0.341\) N/mm2) is by 23% lower than the results of linear (buckling) calculation ( \({{q}_{{{\text{cr}}}}} = 0.443\) N/mm2), which emphasizes the need to take into account nonlinear effects. Particular attention is paid to the influence of a local reduction in the wall thickness (up to 1 mm) as a model of corrosion damage. It has been found that such imperfection reduces the critical pressure by 67% (to \(~{{q}_{{{\text{cr}}}}} = 0.146\) N/mm2) even while preserving 78% of the initial thickness, which shows its high danger for the load-bearing capacity. Nonlinear analysis revealed a restructuring of the buckling failure forms and the presence of unstable bifurcation points on equilibrium curves, which are typical for systems sensitive to imperfections. The results confirm that corrosion damage more considerably reduces the stability of a shell than geometric imperfections in their own shapes. The practical relevance of this work is determined by the prediction of emergency situations, for example, the deformation of railway tanks after temperature effects. The obtained data can be used to optimize diagnostic techniques and to improve the reliability of shell structures in engineering applications.
