Shear Connection Non Linearity and Deflections of Steel-Concrete Composite Beams: a Simplified Method

In steel and concrete composite beams, the incomplete interaction between steel profile and concrete slab leads to an appreciable increase of the beam deflections with respect to full interaction behavior. Moreover, the concrete cracking in hogging moment regions of continuous beams needs to be considered. In this paper, a finite-element procedure considering nonlinear load–slip relationship for shear connectors is presented. Such a procedure accounts for the concrete slab cracking and the resulting tension stiffening effect; it also assumes different load–slip relationships for shear connectors in cracked slab. Some experimental comparisons show the accuracy of the proposed procedure. A wide parametric analysis is performed with reference to the evaluation of deflections for simply supported composite beams. Finally, a simplified method which is able to evaluate deflections for beams with nonlinear behaving shear connection is presented. In steel and concrete composite beams, the incomplete interaction between steel profile and concrete slab leads to an appreciable increase of the beam deflections with respect to full interaction behavior. Moreover, the concrete cracking in hogging moment regions of continuous beams needs to be considered. In this paper, a finite-element procedure considering nonlinear load–slip relationship for shear connectors is presented. Such a procedure accounts for the concrete slab cracking and the resulting tension stiffening effect; it also assumes different load–slip relationships for shear connectors in cracked slab. Some experimental comparisons show the accuracy of the proposed procedure. A wide parametric analysis is performed with reference to the evaluation of deflections for simply supported composite beams. Finally, a simplified method which is able to evaluate deflections for beams with nonlinear behaving shear connection is presented.