Cold-Formed Steel Members with Multiple Longitudinal Intermediate Stiffeners

Abstract

A new procedure for calculating the effective width of stiffened elements with multiple longitudinal intermediate stiffeners is presented. The method determines the critical stress for distortional buckling of the entire stiffened element as a unit, and local buckling of the subelement plates between stiffeners. Approximate expressions for calculating distortional buckling are verified via comparison to numerical methods. The effective width of the element is determined using Winter's equation based on the governing buckling stress. Reduced postbuckling capacity in the distortional mode is considered. Comparison to experimental data and numerical analysis shows the resulting method is a reliable predictor of the flexural capacity of cold-formed steel members with multiple longitudinal intermediate stiffeners in the compression flange.