Study On Seismic Behavior Of Composite Shear Wall With Double Steel Plates And Infill Concrete With Binding Bars

The core wall in super high-rise buildings is usually subjected to high axial compressiveforce and seismic effect. If the traditional RC structural wall is used for core wall,the wallthickness would be excessively thick. The excessively thick wall may result in the increase ofconstruction cost and the difficulty of structural design. Therefor, one effective way to solvethis problem is to develop new forms composite shear wall which show good strength,deformability, energy dissipation capacity and simple construction.A new type of composite shear wall with double steel plates and infill concrete withbinding bars (CSW) is proposed. The mechanical behavior and seismic performance of CSWare studied by experimental method, theoretical analysis and numerical simulation method.The main research work is as follows:(1) Eleven CSW specimens were tested under lager axial compressive force and reversedcyclic lateral load. The main parameters varied in the tests were binding bars spacing, bindingbars setting, axial compressive ration and shear-span ration. The influences of theseparameters on failure characteristics, hysteretic curve, skeleton curve, strength degradation,stiffness degradation, ductility and energy dissipation capacity of the specimens wereobserved. The results indicate that the CSW shows good strength, ductility and energydissipation capacity. The CSW has great seismic performance.(2) Based on the MATLAB platform and the fiber model method, the numericalsimulation model of CSW under compression-bending state was built up by self-compiledprograms. The numerical simulation model was validated by experimental results. The mainparameters varied in the analysis were concrete strength, steel strength, steel ration, theproportional steel of column and wall, depth of section,thickness of concrete wall, diameter ofbinding bars, yield strength of binding bar,binding bars spacing of wall, binding bars spacingof column. The influences of these parameters on the compression-bending capacity of CSWwere investigated. Through regressive analysis of the results of numerical calculation, asimplified formula to calculate compression-bending capacity of CSW was proposed.(3) The constitutive model of core concrete was proposed, which was suitable for finite element (FE) analysis of square and rectangular concrete-filled steel tubular (CFST) columnswith binding bars. Based on the ABAQUS FE platform, the USDFLD subroutine wascompiled, which could consider the changing of Poisson ratio of many materials in loadingprocess. The material models were perfected. The mechanical behavior were analyzed forsquare and rectangular CFST by ABAQUS. The FE model of CSW was built up and validatedby experimental results. The main parameters varied in the analysis were concrete strength,steel strength, steel ration, shear-span ration. The influences of there parameters on shearcapacity of CSW were observed. The mechanical mechanisms of CSW were then analyzed byABAQUS. Through regressive analysis of the results of numerical calculation, a simplifiedformula to calculate shear capacity of CSW was provided.(4) On the basis of the test data (hysteretic curve and skeleton curve), the simplifiedskeleton curve was provided by fitting method. The formulas of key points on the simplifiedskeleton curve were given. Through regressive analysis of the results of degradation ofstiffness, a formula to calculate degradation of stiffness was proposed. A restoring forcemodel of CSW was built up with degradation of strength and stiffness taken into account.