The influence of transverse and longitudinal stiffeners on stability of steel plate girder

An analysis of flexural work of a plate girder in elastic range has been made in the work taking into account stiffeners of a web as a counteraction to web buckling effect. A path of states of flexural equilibrium has been determined as well, also taking into account the axial compressive force. The analysed plate girder has relatively large span and then the bending moment is a dominant one among internal forces, the normal compressive stresses determine local stability loss and application of the transverse stiffeners does not much affect increase of resistance to local stability loss. On the other hand, use of the longitudinal stiffeners increases the buckling sensitivity coefficient, i.e. results in increase of global buckling resistance. Application of the transverse and longitudinal stiffeners over the whole span of the plate girder causes that its global buckling resistance increases about twice, as the value of the buckling sensitivity coefficient raises from 6.04 to 13.24, while its weight increases not much − by 11%. The transverse stiffeners will have meaning when the tangential stresses from shearing forces that usually occur in the areas of support have the crucial influence on local stability loss. Other cases of occurring significant shearing forces are plate girders under overhead cranes and plate girders of railway bridges that are loaded with large forces concentrated at the places of contact with vehicles’ wheels.