ABSTRACT: This paper presents a model for the analysis of composite beams, taking into account the overall shear deformability, warping of the slab cross section and of the steel beam and partial shear interaction between the slab and the girder. A suitable restrained displacement field is introduced by considering the longitudinal displacements given by the product of known warping functions modulated by unknown functions variable along the beam axis. The warping functions are obtained by considering the problem of unrestrained thin-walled members subjected to self-equilibrated elementary load schemes. The governing equations are derived, according to the stiffness method, both in the weak and strong forms starting from the VirtualWork The...