Bending and Shear Behavior of Web Elements with Openings

Abstract

Cold-formed steel C-sections are frequently used as wall studs and floor joists in both commercial and residential construction. To facilitate installation of ancillary systems such as electrical wiring and plumbing, the C-section is manufactured with a web opening. Although the opening offers construction advantages, it may degrade the structural integrity of the member. To quantify the degrading effect of a web opening, a study has been conducted at the University of Missouri-Rolla (UMR). The UMR study included the loading conditions of bending, shear, web crippling, and the combinations thereof. This paper summarizes the results of an experimental study which addressed the behavior of combined bending and shear. A total of 68 beam specimens, with varying magnitudes of bending moment and shear force were tested. Based on the findings of this study, it was concluded that the interaction equation employed by the American Iron and Steel Institute (AISI) specification will provide an adequate strength prediction, provided that the shear and bending capacities are modified to account for the influence of the web opening.