Inelastic behaviour and algebraic characterisation of long cylindrical shells under combined compression and bending

Long thin-walled cylindrical metallic shells, widely used in civil engineering infrastructures such as wind turbine towers and pipelines, exhibit complex structural behaviour under combined compression and bending. This complexity arises from interactions between geometric and material nonlinearities, particularly cross-sectional ovalisation under bending. Current design standards, including Eurocode 3 Part 1-6, lack comprehensive guidance for such loading scenarios. As part of the ongoing development of Eurocode 3 Part 1-6, this study investigates the inelastic performance of long cylindrical shells under combined bending and compression through a detailed finite element modelling program. A wide range of geometric parameters, including radius-to-thickness ratios, lengths, and load eccentricities were analysed to assess the influence of nonlinearities on structural response. Based on the modelled results, algebraic calculation methods are proposed to complement existing design rules, offering more accurate predictions for the buckling and ultimate strength of cylindrical shells under combined compression and bending.