Web crippling of slotted perforated Cold-Formed Steel channels under EOF load case: Simulation and design

Abstract

The development of new Cold-Formed Steel (CFS) channels with staggered slotted perforations has led to advances in improved thermal efficiency of buildings. These new generations of CFS channels reduce the thermal bridging effect interrupting the direct heat transfer across the web. However, the integration of these staggered perforations creates challenges in terms of reduced structural capacity. It is therefore vital to study the structural behaviour under various loading scenarios. Therefore, the web crippling performance of staggered slotted perforated channels under End-One-Flange (EOF) loading condition and flanges unfastened to bearing plate was investigated in the present paper. Finite Element (FE) models were developed to capture the web crippling strength and failure mechanism of these staggered slotted perforated channels. The validity of the FE modelling techniques was ensured by comparing the web crippling experimental results of CFS channels with solid and perforated webs under the EOF loading. Upon validation, an extensive parametric study comprising 360 FE models was then performed with the aim of (i) examining the effect of staggered slotted configurations and (ii) the corresponding degree of web crippling strength reduction. The results provided a direct mean of notable web crippling strength reduction up to 74%. The numerically derived data points were used to develop a reduction factor based new design equation, which can directly be applied to predictive equations of web crippling. The proposed approach yields more accurate and consistent strength predictions and improves the understanding of CFS channels with staggered slotted perforations.