Research On Seismic Performance Of A Novel Self-centering CLB Rocking Wall Structure

In order to enhance the recoverability of building structures after earthquake,a lot of research work of the reinforced concrete rocking wall has been done by researchers.Because of the shortcomings of the reinforced concrete rocking wall such as non-renewable,heavy pollution,high weight,etc.,bamboo,a green material which is proposed to replace reinforced concrete as the new material of the rocking wall.To solve the issues mentioned above,a novel self-centering cross laminated bamboo(CLB)rocking wall is proposed.Systematic research toward conventional friction damper,bending-friction coupled damper and self-centering cross laminated bamboo(CLB)rocking wall is conducted from the research and development of new friction damper,the seismic performance of the CLB rocking wall and so on by means of experimental research and numerical simulation.All achievements in this paper are helpful to further promote the development of high-rise bamboo structure buildings.The major research work and conclusion of this paper are as follows:(1)The conventional friction damper is tested by low cycle repeated loading method and the friction coefficient is measured.The effects of the friction plate material(brass plate and aluminum foam plate),construction torque and loading amplitude on the performance of the conventional friction damper are studied.Based on the experimental study of the conventional friction dampers,a bending-friction coupled damper with variable stiffness is developed.The experimental study of the bending-friction coupled damper is carried out,and the influence of the loading method,the material and diameter of the bending bar on the performance of the friction dampers is explored.The test results show that the ultimate bearing capacity,stiffness and energy dissipation capacity of the bending-friction coupled damper are significantly improved,which is related to the material and diameter of the bending bar.(2)The ABAQUS software is used to simulate the bending-friction coupled damper.The stress nephograms of the plates,high-strength bolts and bending bar are obtained,and the stress distribution and equivalent cumulative plastic strain of the bending bar are analyzed.Comparing the hysteretic curve obtained by numerical simulation with the test curve,the results show that the numerical model is good,and the numerical analysis results are similar to the test results.(3)The conventional friction damper(CFD)is applied to the single-story single-span CLB rocking wall,and the influence of the moment contribution ratio on seismic performance of the rocking wall with CFD is studied by low cycle repeated loading method.The mechanical properties of the CLB rocking wall may change if it continues to suffer the second earthquake without repair after the first earthquake.In order to study this kind of change,repeated working condition tests are carried out for many times.The test results show that when the CLB rocking wall is not equipped with friction damper,it has a full ability of self-centering and has no residual deformation.After the CFD is equipped,the shape of the hysteretic curve of the specimen is "flag" curve.The energy dissipation capacity and the self-centering capacity of the CLB rocking wall is related to the moment contribution ratio.With the decrease of the moment contribution ratio,the energy dissipation capacity of the specimen is stronger and the selfcentering capacity of the specimen is weaker.(4)Based on the test of rocking wall with CFD,the bending-friction coupled damper(BFCD)is applied to the CLB rocking wall.The influence of different moment contribution ratio and friction damper forms on seismic performance of the CLB rocking wall is compared.The test results show that the effective stiffness of the rocking wall with BFCD is larger than the rocking wall with CFD,and the form of bending bar has no significant influence on the effective stiffness.The energy dissipation capacity of the specimen is related to the form of the bending bar.The energy dissipation capacity of the specimen can be improved by adopting the bamboo section bending bar.