Geometric properties and imperfections influence on buckling behavior of Variable-Thickness steel cylindrical shells subjected to combined Loading: Experimental and numerical study

Abstract

In this study, a total of five cylindrical shells with different stepwise wall thicknesses and varying geometric ratios (including Length-to-radius ratio (L/R) and radius-to-thickness ratio (R/t)) were subjected to the same axial pre-compression, followed by a uniform external pressure load, with the axial pre-compression value being constant. The primary objective of this study was to evaluate the buckling capacity, crustal cross-section deformation in the middle of each strake, and failure mechanism in the specimens. The results indicated that the shell with the lowest L/R and R/t ratios demonstrated the highest buckling capacity and exhibited more stability during failure.Furthermore, the experiments were conducted to verify the accuracy of nonlinear finite element analyses by employing ABAQUS FEA. Then, the simulated method was utilized to numerically investigate the effect of the geometric properties, pattern distribution thickness in the height of shells, the number of strakes, and geometric imperfection of the full-scale cylindrical shells. The findings revealed that the distribution of buckling waves and buckling capacity for cylindrical shells with variable thickness strongly depended on the thickened region and the coefficient of distribution thickness pattern in the height of shells. Additionally, in cylindrical shells with varying stepwise wall thickness, the sensitivity to imperfection increased with increasing axial pre-compression.