Finite Element Analysis And Experimental Study On Seismic Behavior Of Solid-web Steel Reinforced Concrete Exterior Frame With Special-shaped Columns

Steel reinforced concrete (SRC) structure with special-shaped columns is thecombination of the SRC structure and the special-shaped column structure, but also hasthe advantages of the two structures. It overcomes the shortcomings of the traditionalreinforced concrete structure with special-shaped columns, such as low bearing capacityand poor seismic performance. The new structure system has widely applicationprospect.Based on the studies of our work team on a large number of special-shaped columnsand joints in SRC structures, a specimen of the solid-web SRC exterior frame withspecial-shaped columns was tested under low cyclic loading to improve the study of thenew structure system. The failure process was observed. The load-displacementhysteretic loops, skeleton curves, load-carrying capacity, stiffness degradation, ductility,deformation capacity and energy dissipation capacity of the frame were studied. Theresults show that the cracks are concentrated in the beam ends and column foots. Thefailure mechanism of the solid SRC exterior frame with special-shaped columns is thebeam-hinged mechanism, satisfying the "strong column and weak beam" designrequirements. The ultimate story-drift rotation and the overall drift rotation are largerthan the limit value specified by the code, indicating the high capacity of deformationand collapse resistance. As the frame failed, the frame has good displacement ductility,whose ductility factor can reach5.3and layer ductility factors are between5.1-5.5. Theload-bearing capacity of the frame is stable and the stiffness degradation of the structureis insignificant. The hysteretic loops are plump, and the equivalent viscous damping coefficient can respectively exceed0.240, therefore, the frame has a good energydissipation capacity.Finite element analysis of the test specimen was simulated by using the softwareABAQUS, the results obtained are in good agreement with experimental results. On thisbasis, the factors affect the P-Δ curve of the solid-web SRC exterior frame withspecial-shaped columns were analyzed by varying parameter. The results show that:with the increment of the axial compression ratio, the horizontal load-bearing capacityof the frame is reduced, and the ductility is lower. With the increment of concretestrength, the initial stiffness of the frame is slightly increased, and the horizontalload-bearing capacity of the frame is improved. But it has no significant effect on theductility. The horizontal load-bearing capacity of the frame is improved by selecting thehigh yield strength steel. The ductility has an increasing tendency. With the limb height-thickness ratio increasing, the horizontal load-bearing capacity of the frame is greatlyimproved, the initial stiffness is also improved, and the ductility of the frame tends todecrease. The higher yield moment ratio of the beams and columns, the higherhorizontal bearing capacity and the initial stiffness are. The ductility decreasesgradually.