Steel and concrete composite beams with flexible shear connection: “exact” analytical expression of the stiffness matrix and applications

A displacement-based finite element model for the analysis of steel and concrete composite beams with flexible shear connection is presented in this paper. No approximations are introduced in the displacement field, because the stiffness matrix and the fixed-end nodal force vector are directly derived from the “exact” solution of Newmarkʹs differential equation. Therefore, the present finite element may employ only one element per member, because internal nodes are only needed for variations of geometrical and mechanical properties and in the presence of concentrated forces. A simple criterion to establish if partial interaction effects may be neglected in the analysis of composite beams is also suggested.