Collapse pressure of randomly corroded spherical shell

The aged spherical shell is consistently subject to corrosion, which can cause a dramatic decrease in loading capacity. To quantify the influence of corrosion on the collapse pressure of the spherical shell, stochastic numerical analysis was performed. The accuracy of the established numerical model is validated through experimental work in which the hollow sphere is locally compressed. The influence of corroded thickness (tc), diameter of corrosion pit (Dc), and geometrical imperfection on random distribution of collapse pressure is revealed. The formula to predict the reduction factor of collapse pressure for a hollow sphere with one corrosion pit is proposed. This formula is suitable for hollow spheres with different D/t ratios where D and t are outer diameter and thickness of hollow, respectively. The influence of Dc/D and tc/t is quantified. The distribution range of collapse pressure decreased with the decrease of Dc. The presented results indicated that the influence of Dc can be ignored when its value is smaller than 20 mm. The material strength does not influence the reduction factor η for analyzed spherical shells. The probabilistic distribution model of collapse pressure can be simplified as Weibull distribution. The conclusions can provide a reference for estimation of aged hollow spheres subjected to negative pressure. © 2022 Elsevier Ltd