Behavior and Design of Cold-Formed Steel Web-Stiffened Channels under Concentrated Bearing Loads

This study focused on the web crippling and design of web-stiffened channel sections made of cold-formed steel (CFS). CFS web-stiffened channels are expected to have higher buckling loads under compression and bending compared to conventional channel sections without stiffened web. However, research on CFS web-stiffened channel sections under concentrated bearing loads is rather limited. A test program consisting of 29 web crippling experiments was carried out under the loading cases of interior-two-flange (ITF), end-two-flange (ETF), interior loading (IL), and end loading (EL). Both flanges of each channel section were bolted to the supports. The test results were used to establish and validate the finite-element models. Then, the validated numerical models were utilized for a parametric investigation to study the influences of cross-sectional geometry, bearing lengths, and web stiffener dimensions. A total of 576 finite-element analyses were performed in the parametric study. The web crippling design formulas for traditional CFS channels included in the current design standards were assessed by comparing the failure loads attained in the tests and numerical analyses to the predicted values. Finally, a design formula was developed for the design of CFS web-stiffened channels under concentrated bearing loads by modifying the codified web crippling unified equation.