Abstract
In case of design of the hybrid girder, there is a certain limitation of the width to thickness ratio of the web specified in some design codes. However,it has been reported experimentally that the composite action of the hybrid girder with much thinner web plate and RC slab can make the ultimate bending strength in positive flexure improve up to fully plastic bending moment. In this study, in order to investigate both the limitation of width to thickness ratio of the web and the ultimate strength of the hybrid girder which consists of different grades of steels for the thinner web and the flange, a parametric FE analysis is carried out for thr hybrid girders subjected to the positive flexure by varying the width to thickness ratio of the web, material strengths of the steels. It is concluded that the ultimate strength of the hybrid girder with thinner web and high yield strength steel, YP500 flange, can be evaluated by the full plastic bending moment and the reduction factor considering the neutral axis position and the width to thickness ratio of the compression area at the web.
