THE BUCKLING OF A PLATE GIRDER WEB UNDER PURE BENDING WHEN REINFORCED BY A SINGLE LONGITUDINAL STIFFENER.

Abstract

The Paper examines the stability of a panel of a longitudinally reinforced plate-web girder underp ure bending. The edges of the panel whicha re bounded by transverse stiffeners are assumed to be simply supported; along the other two edges the flanges are assumed to prevent both rotation and deflexion. Relationships are found between the panel buckling coefficient, K, the area ratio, p, the flexural rigidity ratio, y, and the aspect ratio of the plate, a, for positions of the longitudinal stiffener which are one-fifth, onequarter, and onehalf the web depth from the compression flange. On comparing these relationships with corresponding ones which havbee en obtained for the condition when the flange members only supply a simple pin-joinst upport to the panel, it is found thatt he flexural rigidity whicht he longitudinal stiffener must possesisn order to remain straight when the plate buckles is very much reduced. The analysis shows that from the stated edge conditions the most effective position for a single longitudinal stiffener a its the 0.226 depth position from the compression flange. This compares with the onefifth-depth position when the unloaded edges are simply supported. The Paper also compares the theoretical relationships between K, p, and 7, with experimental results obtained from tests. Agreement is good.