Strength of Plate Girder Web Panels under Pure Shear

Abstract

Nonlinear analyses have been conducted on three-dimensional finite element models of transversely stiffened plate girder web panels (without longitudinal stiffeners) subjected to pure shear, including the effects of initial out-of-flatness. Currently, the design equations for shear in plate girder web panels in the American Association of State Highway and Transportation Officials (AASHTO) and the American Institute of Steel Construction (AISC) specifications account for elastic shear buckling strength and postbuckling strength separately and combine these resisting capacities based on the aspect ratio of the web panels. Although equations in these specifications predict the overall shear strength with reasonable accuracy, they often underestimate the elastic shear buckling strength, due to an underestimation of the rigidity at the flange-web juncture, and often overestimate the postbuckling strength of certain web panels, as a result of excluding the effect of out-of-plane bending stresses. Based on a parametric study of numerical results, new design equations are proposed for the determination of ultimate shear strengths of web panels. To validate these equations, ultimate shear strengths computed from the equations are compared with existing experimental data.