On the Influence of Load Width on Web Compression Buckling Strength

This paper presents an experimental and numerical study on web compression buckling strength of steel wide flange members subjected to concentric loads spread over lengths wider than the member depth. The AISC specification does not include loading width as a parameter for estimating web compression buckling strength, which can occur in steel connections. The strength equations for web compression buckling provided in the specification are limited to situations where the concentric compression load is applied over a very short length, for example, the flange thickness of the beam at beam-to-column (moment) connections. Limited analytical research has been conducted in the past to investigate the influence of load width on web compression buckling strength. Design equations proposed based on these prior (analytical) studies are limited to load widths less than or equal to section depth. This research aims to conduct experimental investigations and provide data that can be used to: (i) validate numerical models, and (ii) evaluate the effects of load width on the buckling strength under sustained loading conditions. Experimental investigations were conducted on wide flange steel members subjected to concentric compressive loading with load widths approximately equal to 2.5 times wider than the section depth. The experimental program also investigated the response of wide flange steel members to sustained loading, ranging from 80-to-90% of the direct strength, on web compression buckling strength. The experimental results were used to develop and benchmark numerical (3D finite element) models. These models accounted for the effects of geometric imperfections, residual stresses and material inelasticity. The benchmarked models can be used to conduct additional numerical parametric studies.

View content