Study On Seismic Performance Of Self-centering CLB Rocking Coupled Wall With Additional Damping System

To make the rocking structure suitable for the wall with a large opening（coupled shear wall）,a selfcentering CLB rocking coupled wall with an additional damping system is proposed in this paper.The rocking coupled wall consists of two CLB rocking walls and a steel truss energy-dissipating coupling beam located between the two walls.Among them,the steel truss energy-dissipating coupling beam is composed of two chords and two dampers as diagonal webs.The dampers adopt a novel buckling-restrained damper with friction energy dissipation proposed in this paper.The hysteretic performance and failure mode of the damper and the energy-dissipating coupling beam are studied through quasi-static tests.In addition,a predictive model of the self-centering CLB rocking coupled wall with a steel truss energy-dissipating coupling beam is established based on the finite element models of the damper,energy-dissipating coupling beam and CLB rocking wall,and a series of parametric analyses is conducted.Finally,the theoretical analysis of the working mechanism of the rocking coupled wall is carried out,and the theoretical skeleton curve is proposed.The main research contents and conclusions of this paper are as follows:（1）Low cycle loading tests are carried out on the buckling-restrained damper with friction energy dissipation（BFD）,and the influences of different variables and different loading protocols on the hysteretic performance,failure mode,ductility and energy consumption of the BFD are studied.The results show that the hysteretic curve of the BFD is stable and fat.When the stopper mechanism of the BFD is activated,the axial deformation of the small plastic segment is limited,and the large plastic segment can continue to deform to provide additional strength and stiffness for the damper.By analyzing the single loading cycle’s energy dissipation of BFDs with different bolt torques,it is found that the energy consumption ratio of the large plastic segment,the small plastic segment and the friction energy dissipation mechanism in the specimen L100S10-V is 0.455: 0.398: 0.106.As the strain amplitude of the constant amplitude loading protocol increases,the failure mode of the BFD will change,from the failure of the small plastic segment first to the failure of the large plastic segment first.Besides,the cumulative ductility index and compression-strength adjustment factor of the BFD can meet the relevant requirements of AISC 341-16,respectively.（2）Quasi-static loading tests are conducted on the steel truss energy-dissipating coupling beam,which shows that the cumulative energy cohnsumption of the energy-dissipating coupling beam decreases with the increase of the height of the coupling beam.The force-displacement responses of te energy-dissipating coupling beams using the BFD with the same sectional areas of large and small plastic segments and using the conventional buckling-restrained damper（CBD）are similar,while the energy-dissipating coupling beam using the BFD with different sectional areas of the large and small plastic segments has a better low-cycle fatigue life.Besides,the failure mode of the articulated damper in the steel truss energy-dissipating coupling beam is a little different from the failure mode that occurred in the BFD tests.A new failure mode is mainly added,that is,the end of the outer tube of the damper breaks.Finally,the theoretical analysis of the force on the end of the articulated damper is carried out,and the calculation equation for the fracture of the end of the outer tube is given.（3）Based on the above test results and the test results of CLB rocking walls by the research team,the validity and accuracy of the finite element models of the BFD,steel truss energy-dissipating coupling beam,and the CLB rocking wall are verified,and a predictive model of the self-centering CLB rocking coupled wall with a steel truss energy-dissipating coupling beam is established.A series of parametric analysis is carried out for this model,and the results show that increasing the wall width can significantly increase the strength,initial stiffness and second stiffness of the rocking coupled wall;Increasing the initial stress ratio of prestressed tendons or increasing the number of prestressed tendons can increase the strength of the rocking coupled wall,but increasing the number of prestressed tendons is more effective,and increasing the number of prestressed tendons can increase the second stiffness of the rocking coupled wall;The energy dissipation capacity of the rocking coupled wall can be effectively adjusted by changing the width of the opening,the inclination angle of the damper and the sectional area of the damper.In addition,a theoretical model of the rocking coupled wall is established and verified by comparison with the numerical results.Finally,the design process of the rocking coupled wall is proposed.