Experimental And Analytical Study On Seismic Behavior Of Self-centering Energy-dissipating RC Column-steel Beam Joint

With the development of modern building structures,RCS(reinforced concrete column-steel beam)frame structures are widely used because they make full use of the mechanical properties of steel structures and concrete structures.At present,the connection mode of the joints of the RCS structure system is mostly rigid connection,and the failure mechanism of plastic beam hinges is expected,which will result in large residual drift after the earthquake.The self-centering structure can reduce or eliminate the residual drift of the structure and restore the structure to its original position after the earthquake.There are few studies on the self-centering RCS structure.Therefore,it is necessary to study the self-centering RCS structure.In this paper,a steel plate damper is proposed and applied to the self-centering energy dissipation beam-column joint of RCS structure.The uniaxial cyclic tensioncompression tests are carried out on the steel plate damper to investigate its bearing capacity and energy dissipation characteristics;On this basis,tests under low cyclic loading of the RCS joints was carried out,and the seismic performance of the joints was analyzed from the aspects of hysteresis curve,skeleton curve,energy dissipation capacity,and self-centering ability;Finally,the ABAQUS software is used to simulate and analyze the nodes.The main conclusions are as follows:(1)Three groups of uniaxial cyclic tests with steel plate dampers were conducted,the experimental results showed that the dampers had good energy dissipation capacity,bearing capacity and initial stiffness.(2)Six sets of self-centering energy dissipation RC column-steel beam joint tests were carried out,including five sets of joint test with steel plate dampers and one set of control experiments without dampers.The results showed that: 1)The hysteresis curve of the joint has the typical ‘flag-shaped’ curve;2)The larger the self-centering parameter of the joint,the stronger the self-centering ability,and the smaller the residual drift after the earthquake.During the test,the joint has a certain degree of prestress loss,resulting in a reduction in the self-centering parameters compared with the theoretical value;3)The energy dissipation of the joints is concentrated in the damper,and the beam and column are in the elastic state during the whole test process,reaching the expected damage goal.After the test is completed,the energy dissipation core plate is replaced,and the selfcentering ability,energy dissipation ability and bearing capacity of the joint are almost unchanged,and the ‘recoverable’ performance goal can be achieved.It performs well in self-centering energy-dissipating RC column-steel beam joint test,and is easy to manufacture and replace.(3)The results of the finite element simulation are in good agreement with the experimental results in terms of hysteresis curve,buckling shape of the energy dissipating core plate,beam end gap-opening,and other aspects,which verifying the influence of self-centering parameters on the seismic performance,indicating the effectiveness of the finite element simulation.