Research On Seismic Performace Of Connection In Innovative Hybrid Coupled Wall System

Hybrid coupled wall system uses the steel coupling beam instead of concretecoupling beam. The steel beam is designed following the standard of eccentricallybraced link beam. It combines the advantages of both good plastic deformability of steelbeam and large lateral rigidity of concrete shear wall. So it is more applicable in highseismic intensity area. The unique superiority of hybrid coupled wall has been payedmuch attention by scientific research workers. Previous studies mainly Focused on theconnection that steel beam is embedded to concrete shear wall. The research group hasput forward a new connection that the steel beam is welded to the steel column which isembedded in the edge of wall. carried out the experimental research, the finite elementanalysis and theoretical study on the seismic behavior of this system are carried out.In order to study the seismic performance of this innovative connection, sixfull-scale connections in hybrid coupled shear wall systems were tested under reversedcyclic loading including strong-connection specimen and weak-connection specimen.The failure process and patterns were obtained. The failure mechanism,load-displacement hysteretic response, load carrying capacity, energy dissipation,deformation components and the influences of parameters were analyzed. Theexperimental results indicate that strong specimens show good seismic behavior withspindle-shaped load versus story drift response. The responses are typical of ductilesteel link beams in EBF. The coupling beams can solve the problem that thereinforcement concrete coupling beam is difficult to set rebar and the ductility factor isdeficiency in coupling beams of small span-to-depth ratios. The failure mode of weakconnection is like the failure of steel beam-steel reinforced column joint, are all in joint shear failure style, and the ability of energy dissipation is found to be better than theconnection of reinforced concrete joints.Based on the experimental results, finite element analysis software ABAQUS wasused to simulate the properties of specimens under low cyclic reversed loading. Finiteelement model chose appropriate tensile and compressive damage constitutive relationsand the action of bond-slip between steel and concrete. The calculation results agreedwith the results of test very well. Parametric analysis of the structure was carried out.The steel web height and thickness in joint region were considered as analysisparameters. The major factors include the steel web height and thickness, diameter ofthe stirrup, diameter of the vertical reinforcement, axial compression ratio, strength ofconcrete, the face bearing plate settings and so on.According to the testing and FEM analysis results, the bearing mechanism ofconnection is analyzed. Based on the assumption for boundary conditions of theconnection in hybrid coupled wall systems, the mechanical model of calculatinghorizontal shear of the connection in hybrid coupled wall systems is suggested. Thecalculation formulas of horizontal shear in joint core area is derived. After analyzing theknown research results, the shear bearing capacity formulas is presented. The test resultsand the calculation results are in good agreement. According to the ultimate bearingcapacity formulas of two types of steel coupling beam and shear bearing capacityformulas of joint core area?two specimens are designed. The accuracy of the calculationformulas is proved through finite element method.