Study On Seismic Performance Of Energy-dissipation Coupling Beams Fabricated With A Steel Damper

Coupling beams play an important role in the shear wall structure.On the one hand,coupling beams constraint shear walls in order to get sufficient lateral stiffness under frequently occurred earthquake.On the other hand,coupling beams dissipate the seismic energy to guarantee the safety of the sturcture under rare earthquake.Coupling beams have great shear effect with small span-depth ratio.Brittle failure will be occurred when coupling beams are subjected to rarely occurred seismic actions.To improve the mechanical performance and failure mode of the coupling beams,different kinds of energy-dissipation coupling beams are raised and studied.However,the existing energy dissipation coupling beams have many disadvantages,such as small rigidity,complex processing and poor economy.Considering the disavantages,a new kind of energy-dissipation coupling beam fabricated with a steel damper is raised.To study the seismic performance of this kind of energy-dissipation coupling beam,theoretical analysis,finite element simulation and experimental study are carried out.Design stiffness and yield shear force of energy-dissipation couling beams is obtained by theoretical analysis of coupled shear wall structures.Energy dissipation efficiency of steel dampers fabricated in couple beams is defined.An energy-dissipation coulpeing beam consists of two elastic segments and a steel damper.Fuction relation between energy dissipation efficiency and stiffness ratio is derived by stiffness relation of the series model.More conculsions are drawn by further analysis and comparison.Energy dissipation efficiency of shear type steel damper changes slowly with the change of stiffness ratio.However,energy dissipation efficiency of flexure type steel damper varies a lot with the change of stiffness ratio.To meet requirements of shear wall structures and to improve the performance of coupling beams,design method of energy-dissipation coupling beams fabricated with a steel damper is raised.Finally,considering coupling beams are components with variable stiffness,equivalent coupling beam is proposed.Based on which,the application of energy-dissipation coupling beams is presented.Models of elastic segments and steel dampers are built by ABAQUS,the finite element analysis software.Stiffiness of elastic segments and steel dampers are obtained.Subsequently,coupling beams sections and steel dampers are fabricated into energy-dissipation coupling beams.Stiffiness of energy-dissipation coupling beams are obtained then.The relationship among the three stiffness are analysed.Energy dissipation efficiency of different kind of steel damper is analysed.Results show that,the stiffness of energy-dissipation coupling beam can be obtained by the calculation method of series model.The energy dissipation efficiency increases with the increase of stiffness ratio.The law of variation of energy dissipation efficiency with stiffness ratio is in accordance with derivation.On the basis of theoretical research and finite element analysis,experimental study on energy-dissipation coupling beam fabricated with a steel damper is carried out.Variable amplitude and constant amplitude cyclic loading tests were carried out on five groups of different types of energy-dissipation coupling beams.Many conclusions are drawn.Failure mode of energy dissipation coupling beam with reliable and reasonable design is the failure of steel dampers.The method of calculation of stiffness of the series model is simple and reliable,which can be used to design the energy dissipation coupling beam fabricated with a steel damper.Through the experimental analysis and comparison,it is found that the application range of energy dissipation coupling beams fabricated with different kinds of steel dampers is different.Based on which,some suggestions for selection are put forward.Steel dampers can be removed and replaced by reasonable design.