Shear-Buckling Coefficients for Slender, Horizontally Curved Plates

Development and implementation of horizontally curved steel members, particularly curved plate girders utilized by the bridge industry for complicated site geometries, continue to occur, and material, analysis, and design advancements allow for more efficient and cost-effective cross sections, resulting in increasingly slender elements. A central byproduct of this enhanced efficiency has been the need to further investigate and mitigate possible global and local stability issues for very slender webs that are primarily loaded in shear. Classical work related to thin plate stability under shear forces was completed by a number of researchers, most notably consisting of work by Timoshenko published in the 1930s. This research produced an equation for the elastic, critical shear-buckling stress and utilized a coefficient, termed the shear-buckling coefficient, to account for plate aspect ratio and edge conditions. The work summarized herein focused on following Timoshenko’s approach to derive equations for simply supported, slender plates that explicitly accounted for horizontal curvature. Steps and assumptions used to derive these equations are presented in detail. A summary of the influence of horizontal curvature on variations of the derived shear-buckling coefficient over a range of geometric properties demonstrated that (1) the derived formulation is reduced to Timoshenko’s formulation for a flat plate; (2) the shear-buckling coefficient of curved plates is dependent on the curvature as well as the web slenderness ratio; and (3) the horizontal curvature could significantly influence the shear-buckling capacity for slender elements.