Finite Element Analysis And Experimental Investigation On Seismic Behaviors Of Seismically Damaged Shear Walls

In this paper,the seismic behavior of damaged reinforced concrete(RC)shear wall repaired with the fiber-reinforced polymers(FRP)was studied by a pseudo-static test and finite element analysis,the main contents of this research are presented as follows:(1)Based on three seismically damaged shear walls,three test specimens were designed and fabricated.The first test specimen is repaired and strengthened with basalt-fiber-reinforced polymer(BFRP)(RW-1).The second test specimen is repaired and strengthened with carbon-fiber-reinforced polymer(CFRP)(RW-2).The third test specimen is repaired and strengthened with BFRP and CFRP(RW-3).The concrete and steel bars in the plastic-hinge zone of damaged reinforced concrete shear walls were replaced,and the repaired shear walls were strengthened with the fiber-reinforced polymers(FRP).The quasi-static tests of three repaired and strengthened specimens were carried out,and the hysteretic curves,skeleton curves,energy dissipation capacities and stiffness degradation of the three tested specimens were obtained.Comparing of the seismic behaviors between the repaired walls and the original walls,the efficiency of FRP for repairing and strengthening seismically damaged shear walls were evaluated.The test results show that the repaired and strengthened method could restore and raise the bearing capacity,ductility and energy dissipation ability of the damaged shear wall,and delay the stiffness degradation of the damaged shear wall,but the initial stiffness of the repaired and strengthened damaged shear wall is slightly lower than that of the original shear wall.The efficiency of CFRP and BFRP on the recovery of bearing capacity of shear wall is similar,but performance of BFRP on the recovery of ductility of shear wall is better than effect of CFRP.(2)The ABAQUS software is applied to simulate the three repaired specimens.The finite element analysis results under monotonic horizontal load are in good agreement with the experiment results which proves that the finite element model and the selected parameters are reasonable and reliable.(3)Based on the reasonable finite element model,the axial compression ratio,FRP layers,damage degree and paste formats on the reinforcement effect w ere analyzed.The FEA results demonstrate that the peak strength?ultimate strength and ductility increase at first and then decrease with increasing axial compression ratio and FRP layers.High axial compression ratio will degrade the seismic performance of damaged RC shear wall.The lower the damage degree is,the better the reinforcement effect would be.The reinforcement effect of paste formats from big to small are combination strengthening with FRP jackets?L-shaped and X-shaped FRP strips,paste formats of FRP jackets and L-shaped FRP strips,paste formats of L-shaped and X-shaped FRP strips.