Experimental Study And Theoretical Analysis Of Improved Scheme On Coupling Beam Of Small Cross-height Ratio With Section Closed Stirrup

In coupled shear wall structure, Coupling beam is the first line of defense of multi-channelseismic line of defense in coupled shear wall,playing a role in Lining wall limbs and transferingload, which is an important energy-consuming components in the shear wall structure.Under thehorizontal loads, Wall limbs occur bending deformation, Coupling beam two end-sides to producethe rotation displacement, making coupling beam withstand the bending moment and shear andtransferring internal force from a wall to another piece of wall. Under strong earthquake, coupledshear wall with suitable bearing capacity, stiffness and good deformation properties of couplingbeams make coupling beam firstly yield before the wall limbs yield, playing plastic deformationcapacity, dissipating of seismic energy, therefore effectively reduce the damage to the walllimbs.Improvement of coupling beam deformation properties effectively improve the structuraldeformation performance. The pros and cons of coupling beam seismic performance directlyimpact on the seismic performance of coupled shear walls.Seismic design method based indirectly on displacement is that assumes the overall lateraldisplacement mode of the structure,transforms practical multi-freedom-degree system intoequivalent single-freedom-degree system, according to structural dynamics method, determinesthe elastic-plastic seismic displacement response of the equivalent single degree of freedomarchitecture, Anti-calculates elastic-plastic seismic displacement response of the originalmulti-degree of freedom system,according to the lateral displacement mode of each floor,checkes whether they meet the threshold requirements. The seismic design method measures theperformance of the structure directly with the displacement indicator, more intuitive, Calculationmethod is also relatively simple and applicable in design, With this method, Plastic requirements of coupling beam to shear wall can be calculated.In architecture and technology of Xi'an University,Qingshan Liu finds a kind of sectionclosed stirrup reinforcement program with little difficulty of construction which makes couplingbeam high ductility and high energy dissipation capacity.Coupling beam of small cross-heightratio with section closed stirrup is a kind of reinforcement program with both Convenientconstruction and Optimum seismic performance.On the basis of this program,the paper uses localno-bonding technology and puts forward an improved program,that is to entangle reinforced usingplastic casing on the range of h/4of coupling beam end, to prevent the bonding of thereinforcement and concrete in order to improve seismic performance of coupling beam.For theseismic performance of bond and unbonded reinforcement program of coupling beam end of smallcross-height ratio with section closed stirrup,This paper has done a test, and compares withoriginal reinforcement program,introducing in detail the throughout trial process,describing theexperimental phenomenon,Studying the kinds of fators such as nominal shear pressure ratio,shear hoop ratio,stirrup characteristic value and so on to the influence of failure mode, ductilityand energy dissipation of coupling beam end bond and unbond of small cross-height ratio withsection closed stirrup.At the same time, nonlinear finite element numerical simulation analysis isconducted using ANSYS9.0,theoretical and experimental results is compared and analysized, Alsomake up the drawback that a test device can not completely truly reflect actual loading state of thecoupling beam. Test results is coincided with numerical simulation results.