Section failure due to combined moment, shear and web crippling forces in cold-formed steel deckings

This paper presents an experimental and numerical investigation into section failure due to combined moment, shear and web crippling forces of two common cold-formed steel deckings: re-entrant and trapezoidal deckings. A similar investigation into web crippling failure of both deckings is reported separately. In this paper, it is reported that a number of one point load tests on simply supported deckings are performed to study the structural behaviour of deckings under concentrated forces. Moreover, advanced three-dimensional finite element models with material, geometrical and boundary non-linearity are establish to simulate the section failure of these two deckings under combined moment, shear and web crippling forces. Comparison on both the section failure resistances and the deformed shapes at failure between the numerical and the test results is found to be highly satisfactory. Moreover, an extensive parametric study is performed to generate design data for section failure under combined actions in deckings with different steel grades and clear spans under a practical range of bearing lengths. It is shown that the proposed finite element models are effective to predict section failure in both deckings under combined actions. Furthermore, a simple and yet effective design rule is also proposed which employs directly the numerical results obtained from the parametric study. Further investigation will be carried out to validate the general applicability of the proposed finite element models and the design rules to cover other deckings with similar configurations and cross-section dimensions.