装配U形阻尼器的SMA自复位钢框架梁柱节点抗震性能研究OA北大核心CSTPCD

To solve the problem of low SMA material utilization of traditional self-centering steel beam-to-column connections with SMA bars during the working phase,a kind of self-centering steel beam-to-column connection was proposed,which was equipped with U-shaped dampers and superelastic SMA bars connected through steel column flanges.The proposed connection can simplify the process of design,construction and replacement of energy-consuming components,and accelerate the post-earthquake structural recovery.In this research,the mechanical properties of the connection and the critical components were analyzed and the force deformation theoretical model was proposed.The superelastic properties of SMA bars were investigated by cyclic tensile test.On this basis,a full-size side-column connection specimen was designed,and its bearing capacity,initial rotational stiffness,residual deformation and hysteretic energy dissipation were studied through a pseudo-static test.The results show that the SMA bars in the connection can effectively stretch,and provide self-centering driving force.The two limbs of the U-shaped dampers can generate relative deformation and thus enable plastic energy dissipation.The shear bolts at the beam web can slide in the long hole of the steel bracket,and there is no shear deformation in the core area of the beam-to-column connection.The residual inter-story ratio of the specimen is only 0.004 9 rad at the end of the cycle with a designed inter-story ratio of 0.04 rad,and the beam and column are always in the elastic stage without damage during the test,which reflects a good self-centering ability and repairability.The initial rotational stiffness and ultimate bending moment of the specimen are both smaller than those of steel moment-resisting beam-to-column connections.Moreover,the maximum inter-story ratio of the specimen is 0.05 rad,which meets the deformation design requirements.