Available rotation capacity of composite bridge plate girders under negative moment and shear

This paper presents a study of the behaviour of slender composite plate girders under negative bending moment and shear. It is known that at composite bridge intermediate supports, the slender composite beams have very limited ductility, which has led to the adoption of elastic methods for the design of these members. However, this elastic design is time-consuming and does not correspond with real beam behaviour. In order to propose a simpler and more intuitive design method which corresponds better with real beam behaviour, the support region limited ductility must be quantified. In this study, slender composite beam ductility under shear and negative bending is investigated, using a numerical model developed specifically for this purpose. On the basis of the parametric analysis results, a simple analytical model for quantifying the slender composite beam support region ductility is proposed and verified.