Ultimate load of cylindrically curved panels under in-plane compression and bending—Extension of rules from EN 1993-1-5

• Past and current approaches for the ultimate strength of curved panels under pure compression and pure in-plane bending are discussed.
• Relevant parameters are identified and calibrated against numerical simulations. Key parameters are the curvature parameter and the reduced slenderness parameter.
• A comprehensive parametric study is performed and an empiric formulation based on the effective width concept for the ultimate strength of curved panels is achieved.
• The ultimate behaviour of cylindrically curved panels is characterised by ρ–  λ¯ curves similar to those obtained for plates.
• Within the parametric range, the limit for the curvature parameter imposed by EN 1993-1-5 is correct.

A numerical study on the post-buckling behaviour of simply supported short cylindrically curved panels, with longitudinal edges unconstrained and loaded edges constrained (internal element of a section), including the influence of curvature and loading type (pure compression and in-plane bending) is presented in this paper. Additional relevant parameters are identified and their influence on the ultimate strength of cylindrically curved panels is studied. Numerical results of the ultimate reduction factor from the parametric study are converted into geometry (width) reduction factors by an iterative routine. Subsequently, an extension of rules for internal plated members’ ultimate load calculation from EN 1993-1-5 is proposed based on the effective width concept. It is concluded that (except for stocky panels) the increase in the curvature parameter led to an increase on the cylindrically curved panel's resistance and that the upper limit proposed by EN 1993-1-5 to the value of the curvature parameter is reasonable. Finally, a statistical study is performed that concludes that the proposed approach provides an accurate estimate of the ultimate load.