Intermediate Stiffeners for Thin-Walled Members

An effective width approach is presented for predicting ultimate strengths of thin-walled compression elements with intermediate stiffeners. The study is limited to intermediately stiffened assemblies in which the stiffener is located in the center of the stiffened plate and is of relatively small width compared to the plate. In conjunction with procedures for predicting ultimate strength, a requirement for adequate stiffener rigidity is given. Stiffener adequacy is assessed as that rigidity for which the ultimate strength of each component plate element, one on either side of the stiffener, equals that of an element of similar dimensions and material properties, but supported by webs at both longitudinal edges. Critical and post-critical behavior are studied analytically and experimentally; however, the stiffener requirement is developed based primarily on the experimental results. Simple formulations for assessing the performance of the stiffener and plate elements are presented.