Study On Axial Compressive Behavior Of Steel-Damping-Concrete Composite Wall

Versatile applications of steel-concrete-steel(SCS)composite structure in building cores,anti-blast and impact protective structures,road and bridge decks,shield and immersed tunnels are carried out due to its mechanical characteristics of high capacity,rigidity,ductility,blast and impact resistance,and has good performance in construction efficiency.Energy dissipation technology can consume the seismic energy by its damping effect under large earthquakes and super-large earthquakes and quickly attenuate the seismic response of the structure,thus protecting the main structure from excessive damage during strong earthquakes.Based on the advantages of SCS composite shear wall,combined with the theory of energy dissipation and the concept of fabricated structure,a new type of steel-damping-concrete(SDC)composite shear wall was proposed,which has the dual functions of carrying energy consumption.In this thesis,theoretical analysis,experimental research and finite element analysis were combined to study the axial compression performance of the SDC wall.The main research contents are as follows:(1)Conceptual design of the SDC wall are carried out.The preliminary design of the damped interlayer(between the wall steel plate and the concrete,between the binding bar and the concrete)was proposed,and the finite element simulation is carried out.The results show that the ductility of the SDC wall with only the damping layer cannot be improved,with the bearing capacity decreasing significantly.Through reviewing the literature and theoretical analysis,the design was improved.Two types of reinforcing approaches including steel sheets and sleeves were utilized to enhance the weakness of the damping layer on the concrete core.The binding bar was selected as the shear connector of the wall to optimize the combined shear force.(2)The rubber uniaxial tensile test was carried out to obtain the rubber constitutive curve;five sets of rubber simple shear tests were carried out to investigate the shear mechanical properties of the rubber,guiding the design of the SDC wall and providing data support for the subsequent work.(3)The finite element analysis and parameter analysis of the axial compression performance of the SDC wall were carried out.The numerical simulation of the SDC wall and the conventional SCS wall was carried out and the mechanical properties of the two composite walls were systematically studied from the aspects of initial stiffness,failure mode,ultimate compressive bearing capacity and ductility,demonstrating the superiority of axial compression performance of the SDC wall.The influence of the damping layer thickness,concrete thickness,steel plate thickness,binding bar spacing,and the shape and size of steel sheet on the axial compression performance of the SDC wall were investigated.The design criteria for damping layer thickness were proposed.(4)The investigation of the axial ultimate compressive resistance of the SDC wall was conducted.According to the numerical analysis results,the simplified weakening influence on the bearing capacity of the concrete part of the thickness of the damping layer is fitted.Based on the existing specifications and literature,the calculation formula of the axial bearing capacity of the double-plate combined shear wall with damping interlayer is derived..