Longitudinal Shaer in Composite Beams

Longitudinal shear has important influences on the performance of composite beams. According to Eurocode 4, with cross-section class 1 and 2 in combination with ductile shear connectors, a plastic method, considering redistribution of longitudinal shear force is allowed. The conditions therefore are full development of plastic moment resistance and sufficient slip at interface to reach the plateau of P-δ curve of the shear connectors. However, for slim-floor beams, it is to question if the above-mentioned method can be applied. To answer it, related topics still need further investigation, which is the focus of the author’s Ph.D work. This paper presents part of the first stage results on the theoretical analysis of longitudinal shear, considering the influence of plasticity of the beam. For composite beams with rigid shear connectors, non-linear shear stress distribution appears in the plastic region, which influences the shear connector arrangement. However, detailed theoretical research is still hard to be found. In this work, based on a simple beam partly in plastic zone, mathematical equations are developed to calculate the plastic zone height and longitudinal shear stress distribution. Benchmarks with ANSYS and existing tests are performed