Experimental Study On Seismic Performance Of Combined Shear Wall With Replaceable Friction Dampers

Since the self-reset shear wall relaxes the constraint between the foundation and the wall,it can reduce the damage to the wall under earthquake.By using the prestressed tendons to provide the restoring force,the deformation of the shear wall can be restored to its initial position after unloading,so that its residual deformation is small,the shear wall has the function of self-resetting.Based on the concept of recoverable functional structure and combined with the idea of "replaceable ",this paper sets up replaceable energy dissipation members in the corner area of self-reset shear wall,on which the plastic deformation can be concentrate,and realizes the rapid recovery of the structural function by replacing the replaceable members after the earthquake,so as to facilitate the repair after the earthquake.A composite shear wall with replaceable slotted-bolted-plate friction energy dissipators is presented in this paper.The components of the wall include two vertical unbonded prestressing tendons,X-shaped steel plate concealed bracing,shear steel bar,bent-up energy dissipation bars,replaceable friction energy dissipator at wall corner and others.The prestressing tendons used to provide the self-reset capacity,together with the replaceable members set up at the wall corner,make the shear wall realize the reasonably application in four mechanisms: swing,self-reset,replaceable and energy dissipation.In order to study the seismic performance of the composite shear wall with replaceable slotted-bolted-plate friction energy dissipators systematically,pseudo-static test and finite element numerical simulation are completed in this paper.The main research contents and results are as follows:(1)A composite shear wall with replaceable slotted-bolted-plate friction energy dissipators is proposed,and the pseudo-static loading tests are carried out.The hysteresis and skeleton curve,lateral bearing and deformation capacity,energy dissipation ability and stiffness degradation of the wall are obtained.The following conclusions can be drawn by comparing with the experimental results of the cast-in-situ shear wall with steel plate in reinforced concrete: the damage of the wall proposed in this paper is significantly reduced and with less cracks;the bearing capacity and stiffness are lower than the traditional cast-in-place walls,but the deformation capacity is significantly enhanced,and the yield displacement,peak displacement and ultimate displacement are all obviously increased,showing good deformability and ductility;the replacement of corner members makes it easier to repair after earthquake and saves the economic cost of repair.(2)By using the finite element analysis software ABAQUS,the shear wall proposed in this paper is simulated and analyzed under the horizontal monotonic loading.The force displacement curve obtained from the simulation is compared with the skeleton curve obtained from the tests.And it is found that the results of the two are relatively consistent,which proves that the numerical model and parameter setting established in this paper are reasonable.(3)On the bases of the finite element model,the parameter analysis of the shear wall is carried out,and the effects of different axial compression ratio,cross-sectional area and initial pretension of prestressed reinforcement,diameter of bent energy dissipating reinforcement,bolt pretension and friction coefficient of friction energy dissipating device on the seismic performance of shear wall are studied.Raising the axial compression ratio can improve the lateral bearing capacity of the wall to a certain extent;increasing the area of the prestressed reinforcement and the diameter of the bent energy dissipating reinforcement can improve the bearing capacity and rigidity;heightening the initial prestress of the prestressed reinforcement has little effect on its seismic index;by adding the bolt preload and friction coefficient of the friction energy dissipating device,the bearing capacity and rigidity of the wall can be significantly increased,while the energy dissipating energy capacity can be enhanced.