Ultimate strength of locally damaged steel stiffened cylinders under axial compression

• Benchmark study on ultimate strength assessment of damaged steel stiffened cylinders.
• Close agreement between the experimental test results and the numerical predictions.
• Case studies on ring-stiffened and orthogonally stiffened cylinders are provided.

This paper focuses on the load-carrying behaviour of large diameter thin-walled stiffened cylinders with local damage when subjected to axial compressive loading. The case considered in this study corresponds to the residual strength assessment of columns of floating offshore structures with damage resulting from collisions with supply vessels. Numerical simulations of axial compression tests, which examine the collapse behaviour and the ultimate strength of ring- and orthogonally stiffened cylinders dented by a knife-edged indenter, are presented. The behaviour of eight small-scale ring-stiffened cylinders and four orthogonally stiffened cylinder specimens is analysed. Finite element analyses were performed using the ABAQUS FEA software package, and a close agreement between the experimental test results and the numerical predictions was achieved. To assess the factors influencing the reduction in ultimate strength under axial compression and to clarify the progressive collapse behaviour, further analyses were performed on design examples of ring- and orthogonally stiffened cylinders, considering both intact and damaged conditions.