Seismic Performance Of Innovative Coupled Double Steel Plate Concrete Composite Walls

The double steel plate composite shear wall is composed of the outer steel plates and the inner filling concrete.It is a kind of anti-lateral force system with high strength,good compressive capacity,excellent ductility and energy dissipation capacity.Coupling beams are set between the composite shear walls to form a coupled double steel plate composite shear wall(CDSCW),which can meet the needs of opening doors and windows in the building.It can also be arranged more flexibly.Not only the connection is easily damaged,but the cross-sectional size is also limited when the coupling beams are directly welded to the outer steel plate of CDSCW.This paper proposes an innovative CDSCW,which set H-shape steel column between the walls.Not only can it ensure the reliable connection of the steel coupling beams and the wall limbs,but also the disassembly and replacement of the coupling beam.Firstly,the stress analysis of the innovative CDSCW is carried out,and the theoretical calculation formula of its ultimate bearing capacity is derived on this basis,and the calculation formula of its plastic calculation coupling ratio is proposed for design specifications.Then,the theoretical bearing capacity of the innovative CDSCW in the previous experiment is calculated through the theoretical calculation formula and compared with the experimental results to verify the authenticity and accuracy of the calculation formula.Elaborate finite element models of 13 innovative straight CDSCWs and 9 innovative T-shape CDSCWs were established by using ABAQUS.Monotone pushover analysis and reciprocating loading analysis were carried out.With strength,stiffness,deformation and energy dissipation capacity as the main performance indicators,the influence on the seismic performance and failure mechanism of the innovative CDSCW caused by coupling beam’s deformation characteristics,coupling ratio,axial compression ratio is studied.The analysis results show that a reasonably designed CDSCW has multiple seismic lines and a reasonable yield mechanism.The first is the yielding of the coupling beams,then the yielding of the wall limb,and finally the plastic hinge forming at the bottom of the wall limb.The strength and initial stiffness of the innovative CDSCW increase with the increase of the coupling ratio,but an excessively large coupling ratio will cause the coupling beams and the wall limbs to yield at the same time.Such unreasonable yield mechanism will causes reduction of the energy dissipation capacity of the innovative CDSCW.The bigger the axial compression ratio,the more obvious the degradation of the bearing capacity and stiffness of the innovative CDSCW,and the ductility and energy dissipation capacity decrease as well.Increasing the coupling ratio within a reasonable range can improve the bearing capacity,ductility and energy dissipation capacity of the innovative CDSCW with axial compression.The ductility of the T-shape CDSCW is better than that of the straight CDSCW when working with axial compression.