Strength of Webs Subjected to Compressive Edge Loading

Abstract

The behavior and strength of hot rolled beams and fabricated plate girders, subjected to localized edge or patch loading in the plane of the web, is analyzed. Numerous tests carried out over the past 50 years have indicated that failure occurs due to web crippling, which is characterized by elastoplastic postbuckling of the web plate accompanied by the formation of a plastic collapse mechanism in the flange. The tests have also indicated that ultimate loads are approximately proportional to the square of the web plate thickness, other parameters such as web depth, flange width and thickness, and even material yield strength, being relatively much less significant. Available test results are summarized and previously developed mechanism solutions for patch loading between vertical web stiffeners are modified to provide improved predictions of failure loads. The mechanism solutions are also reduced to simple closed form equations for routine practical application, which are adapted to predict web crippling failures at simple end supports.