双钢管混凝土构件滞回性能试验与分析OA北大核心CSTPCD

In order to investigate the hysteretic behaviour of concrete-filled double tubular(CFDT)columns,the quasi-static tests on 12 square CFDT members with inner circular steel tubes were completed.The influence of the axial load ratio(0.2,0.4 and 0.6)and the diameter-thickness ratio(30,44.5 and 57)of inner circular steel tubes on the failure modes of specimens,horizontal load-displacement curves and seismic performance were examined.Based on the fiber beam element subroutine iFiberLUT and ABAQUS software,a numerical model was developed to predict the test results and analyze the effects of various parameters on the horizontal load-displacement skeleton curves.The test results show that the circumferential local buckling of outer steel tube in the lower zone of columns gradually become obvious with the increase of the axial load ratio,while the diameter-thickness ratio of inner steel tube exhibit slight effect on the deformation capacity of columns.Within the parameters of this study,all horizontal load-displacement hysteretic loops are relatively full,and the average value of displacement ductility coefficient and viscous damping coefficient of all specimens are 0.326 and 0.6 respectively,showing a superior deformation and energy dissipation capacity.With an increase in the axial load ratio,the bearing capacity,the ductility and horizontal stiffness of specimens decrease,but the strength degradation is slight.When the axial load ratio increases from 0.2 to 0.6,the cwerage peak load decreases by 53.4％.The parameter analysis indicate that with an increase in the width-thickness ratio,the improvement of the diameter-thickness ratio of outer steel tube can lead to a more obvious increase in the peak loak of members,but increasing the axial load ratio can mitigate the influence of the diameter-thickness ratio of inner steel tube on the bearing capacity.