Displacement method for the long-term analysis of steel–concrete beams with flexible connection

The long-term behavior in the service stage of continuous composite steel-concrete beams with deformable connectors subjected to uniaxial bending and axial load is presented. The problem is dealt with by recurring to the displacement method, assuming the bending curvature and the longitudinal deformation as unknowns, and obtaining a system of differential and integro-differential equations. The results are compared with literature experimental tests. A case study is then discussed, referring to a continuous beam subjected to permanent and variable loads, to concrete shrinkage, and to a vertical displacement imposed to the central support or to the prestressing of the central part of the beam.