A new model for composite beams with partial interaction

A theoretical formulation for the deflection of composite beams with consideration of interface slip is derived. The exact closed-form characteristic equations for composite beams with interlayer slip are derived for the boundary conditions. The equations also consider deflections and slips in the cross-section, leading to determinations of internal forces in the cross-section. Based on the research, practical applications are compared with the corresponding transformed section method. The results show that the theory is correct and convenient for solving problems of the analysis of steel–concrete composite box girders. Arbitrary cross-internal forces of the steel–concrete composite box girders are also obtained. The results provide a theoretical basis for the safe design of steel–concrete composite box girders.