Finite element analysis of cold-formed steel channels with solid and slotted webs subjected to web crippling under interior two flange load case

The numerical study was undertaken to investigate the web crippling behaviour and capacities of cold-formed steel channels with staggered slotted perforations with their flanges unfastened to the supports under the interior two flange load case. Finite element models were developed in ANSYS and validated using experimental results. The effect of initial geometric imperfections on the web crippling capacity was investigated. The closest web crippling capacities for the solid and slotted models to the web crippling capacities obtained from the tests were obtained for the scaling factor of the initial geometric imperfection of -d1/150. The results show that the developed finite element models predicted the web crippling capacities and failure mode shapes of the solid and slotted channels. Proposed design equations for perforated channels showed a good agreement with FE results. However, the formulas are based on the test results of a limited range of sections and perforation patterns. The FE models can be used to investigate the effects of various geometrical and mechanical parameters of the slotted channels in further parametric studies.