MCL型复合销连接件抗剪承载机理及影响因素分析OA

To investigate the bearing mechanism of modified clothoid(MCL)-shaped composite dowel shear connectors and the influence laws of various factors on their shear bearing capacity,the stress states and failure modes of the steel dowel,concrete dowel,and transverse through-reinforcement that constitute the MCL-shaped shear connector were deeply analyzed in this paper based on an experimentally validated finite element model.Furthermore,the influence laws of transverse through-reinforcement,steel dowel thickness,and concrete strength on the shear bearing capacity of the MCL-shaped composite dowel were explored.The research results indicate that the bearing process of the MCL-shaped composite dowel exhibits elastic,elastoplastic,and failure stages.When the MCL-shaped composite dowel reaches its ultimate bearing capacity,the concrete dowel is severely damaged,dominated by shear failure;the steel dowel is in a compressive-shear state and locally enters a plastic state.Compared to the lower transverse through-reinforcement far from the shear action end,the upper transverse through-reinforcement is significantly deformed and serves as the primary source of ductility for the concrete dowel.Increasing the concrete strength can enhance the shear bearing capacity of the MCL-shaped composite dowel and delay the development of splitting cracks and prying failure.A larger diameter of the transverse through-reinforcement leads to a stronger shear resistance capacity.The thickness of the steel dowel significantly affects the shear performance of the MCL-shaped composite dowel,determining whether the shear bearing capacity of the MCL-shaped composite dowel is controlled by steel dowel failure or concrete shear failure.