Study On Mechanical Behavior And Design Method Of Buckling-Restrained Steel Coupling Beam With Shear Yielding Failure Mode

Coupling beam is the key energy dissipation component to improve seismic performance of coupled shear wall.In this paper,a new type of energy dissipation member of shear wall structure,buckling-restrained steel coupling beam with shear yielding failure mode,was presented: by setting the restraint plate on both sides of the web of the steel coupling beam,the restraint plate and the web of the steel coupling beam can be effectively connected with the tension screw without contacting with the flange,the mechanism of unbonded deformation between the web plate and the restraint plate in the in-plane interaction was constructed,which can avoid the failure of the constraint plate due to the direct participation in the shear,the constraint plate was used to restrain the out of plane deformation of the web,providing stable buckling restraint,so that the web was similar to the in-plane stress.Then the ductility and energy dissipation capacity of steel coupling beams under earthquake can be improved.The restraint plate adopted prefabricated construction,which was convenient to replace,and reduced the cost of post earthquake maintenance and reinforcement.As a new type of high-rise shear wall structure,the “buckling-restrained steel coupling beam with shear yielding failure mode” had a large initial stiffness and ultimate bearing capacity,good ductility and hysteretic behavior.Furthermore,because the restraint plate can be protected from damage during loading,which can provide stable and durable out-of-plane support for steel webs,it was very suitable for application in high-rise and super high-rise buildings in seismic regions.In this paper,the experimental study,theoretical analysis and numerical calculation of the buckling-restrained steel coupling beam with shear yielding failure mode were carried out:(1)The quasi-static test of 8 buckling-restrained steel coupling beams with shear yielding failure mode was performed,some general rules and conclusions were obtained under the action of horizontal load under the condition of different parameters,which verified the correctness of the theoretical and numerical results.(2)A finite element model was established to calculate the yield behavior of the steel beam with buckling constraints on the ABAQUS finite element software,which can be taken into account both geometry,physics and boundary nonlinearity.By defining the surface contact,it can simulate the interaction between the steel plate and the plate.(3)On the basis of theoretical analysis and a large number of parameter calculation results,the design and calculation formulas of the minimum restraint plate thickness and the maximum spacing of the bolted joints were given.(4)Based on a large number of numerical analysis,the formula for calculating the ultimate bearing capacity and the initial stiffness of the buckling-restrained steel coupling beam with shear yielding failure mode were presented.And the formulas were in good agreement with the finite element analysis results,then the restoring force model of buckling-restrained steel coupling beam with shear yielding failure mode was presented on the basis of the formula for calculating ultimate shear capacity and initial stiffness.