Seismic Performance Of Frame-shear Wall Structure With Steel Truss Coupling Beam

Steel coupling beams have excellent seismic performance for overcoming deficiency in ductility and shear bearing capacity of reinforced concrete coupling beam due to small span-to-depth ratio.In this thesis the steel truss coupling beam was clearly defined and seismic design mission were put forward to distinguish the regular steel truss.And then the steel truss coupling beam,shear wall with the steel truss coupling beam and frame-shear wall structure with the steel truss coupling beam were studied.Finally a design theory and method based on the proposed seismic design mission were put forward.The main research contents and results include as following:1.The concept of steel truss coupling beam has been perfected and the seismic design mission of steel truss coupling beam has been clear based on both the characteristics of steel truss and seismic requirements of buildings to coupling beams.The steel truss itself has advantages including ductility and energy dissipation,but the one suitable for coupling beam needs more than these.The steel truss coupling beam still needs enough stiffness to connect shear walls effectively and its member bars need appropriate cross sections to dissipate seismic energy.2.Based on the proposed design mission and existing experimental results,parameter analyses were carried out on steel truss coupling beam about its working mechanism and deformation pattern.As results range of area ratio of web member to chord was put forward and the area ratio was preliminarily confirmed.3.Deformation pattern of shear walls with steel truss coupling beam in failure was studied.And shear bearing capacity,shear stiffness and shear stiffness ratio of steel truss coupling beam to shear wall based on story drift were suggested.The ranges of the area ratio and stiffness ratio were confirmed consequently.4.A design method was supposed based on the above stiffness ratio and area ratio.The proposed design method can not only make the steel truss coupling beam dissipating seismic energy to reduce the damage of the structure,but also ensure steel truss coupling beam connect shear walls effectively.5.A shaking table test about frame-shear wall structure with steel truss coupling beam designed according to the area ratio and stiffness ratio and elastic-plastic time-history analysis on the shaking table model were carried out in order to study its dynamic behaviors,acceleration and displacement response.The results show that the supposed design method is valid.Above all,the work in the thesis stated clearly working mechanism of steel truss coupling beam under earthquake and also demonstrated its excellent seismic behaviors.On the other hand,a seismic design method based on area ratio and stiffness ratio was suggested.And so the work will absolutely contribute to popularization and application of the steel truss coupling beam.