Influence of end support configurations on the web crippling resistance of cold-formed trapezoidal sheeting

The slender geometry of trapezoidal sheeting makes it prone to web crippling failure, caused by high-intensity loads, typically originating from end or internal support reactions. The objective of this research is to study the influence of the bearing configuration on the web crippling capacity of multi-web trapezoidal sheets subjected to loading near their free ends. This paper is a continuation of a previous work by the authors, in which a finite element model was used to predict web crippling capacity and subsequently investigate the associated failure mechanisms. The article presents a parametric numerical study using such a model, investigating the factors that influence the crippling capacity of trapezoidal sheeting under EOF loading; i.e. free-end length, stiff bearing length, sheet thickness and depth. Additionally, the evolution of existing analytical formulations is reviewed, and their limitations are identified and discussed, based on the results of the parametric study. The results show that the first-generation Eurocode formulation is over-conservative for trapezoidal sheeting. Consequently, a modification of the effective bearing length definition is proposed. The revised formulation incorporates the interdependence between the active bearing length and the free-end length, introduces a transition between Loading Categories 1 and 2, and improves the prediction accuracy. The proposed modification has been implemented in the second-generation of EN1993-1-3 design rules, obtaining a smooth transition between two loading categories (1 and 2) with the redefinition of the bearing length for cross-sections with two or more webs. • FE parametric study reveals EOF web crippling behaviour in trapezoidal sheeting. • First-generation EN 1993-1-3 is over-conservative for multi-web end supports. • Web crippling resistance in Category 1 increases gradually with free-end length. • A new effective bearing length definition eliminates abrupt resistance jumps. • The revised formulation is adopted in second-generation Eurocode 3 (EN 1993-1-3:2024).).