The Buckling Strength of Axially Compressed Thin Circular Cylindrical Shells Subjected to Dent Imperfection

Buckling is the most common type of failure associated with circular cylindrical shells (CCSs) subjected to axial compressive forces. This is mainly due to large radius-to-thickness (R/t) ratio of such shells, making them very thin structures. The buckling stress of these kinds of shells highly depends on the geometric imperfections which are practically hard to be avoided throughout the service life of the structure. The presence of a localized damage (dent) is found to reduce the buckling strength considerably. In this study, the effect of dent imperfection on the buckling strength of CCSs having large R/t ratios is numerically investigated. The R/t values are selected to be large enough to ensure elastic buckling for the entire parts of the shell except near the dent where it is hard to be avoided due to the stress concentration. A finite element (FE) simulation is used to study the effect of the different dent parameters: size, depth, and position on the buckling strength. The obtained results indicate that for the case of shells with large R/t ratios, the amount of reduction in buckling strength due to dent ranges from 13 to 53% without a remarkable trend for its relationship with the size, depth, position of the dent; and R/t.