Performance of Steel Plate Girders with Inclined Stiffeners

Abstract

Slender webs in steel plate girders are prone to local and shear buckling at relatively low shear and thus, need be stiffened to increase the strength and stability of the girders. The conventional way is to provide vertical stiffeners at specified intervals, but this practice serves only to prevent the buckling of web. Provision of inclined stiffeners, in addition to improving buckling resistance, forms a truss-like girder which allows those stiffeners to carry some percentages of forces exerted in the girder. This paper, therefore, presents the ultimate performance of thin-webbed plate girders containing inclined stiffeners. Five simply supported plate girders of practical size were tested to failure under concentrated load applied at the mid-span. This study focuses on the effects of different inclination angles of intermediate stiffeners, 𝜃 on the load carrying capacity and post-buckling behaviour. Five different inclination angles, viz., 90°, 75°, 60°, 45° and 30°, measured from the bottom flange, were accounted for in the test series. Considerable variations of strength, failure characteristic and load-deflection response can be observed due to effects of such inclinations. Test results have shown significant increases in the ultimate strength from 11% to the extent of 50% as the angle of inclined stiffeners reduced. All the girders exhibited shear-dominated behaviour in the web panels at failure.