Study On Seismic Performance Of Reinforced Truss Double-Layer Steel Plate Infill Concrete Composite Shear Wall

To solve problems of existing steel-concrete composite shear walls,difficult construction,high cost and insufficient use of mechanical performance,a steel reinforced truss double-layer steel plate filled with concrete composite shear wall was proposed on the premise of ensuring the basic mechanical properties of the composite shear wall,convenient construction and better economic performance as well.Reverse-cyclic tests of 6 double-steel plate infill concrete composite shear wall specimens with steel reinforced truss were carried out to study the effects of parameters on shearing capacity,hysteretic curves,skeleton curves,ductility,stiffness degradation strength degradation and energy dissipation.Then,numerical models of the new composite shear walls were established using finite element software ABAQUS,and the influences of parameters such as diameter of steel reinforced truss,setting of steel reinforced truss,concrete strength and steel plate thickness on the mechanical properties and failure mechanism were further studied.Then the calculation method of the bending capacity of the new composite shear wall is studied.Finally,in order to investigate seismic performances of the new composite shear wall in an overall high-rise structure,finite element model that can accurately simulate seismic performance of the new composite shear walls in the overall structure was established by using nonlinear analysis software Perform-3D.By comparing the overall structural performances and component damage of the new composite shear wall structure and ordinary composite shear wall structure,seismic performances of the new composite shear wall with steel reinforced truss in overall structure were evaluated.Main researches and conclusions are as follow:(1)Six new composite shear walls with different parameters,spacing of steel reinforced truss,arrangement direction of steel reinforced truss,continuity of steel plate inside the end column and whether steel reinforced truss arranged,were designed,and reverse-cyclic tests were carried out to investigate seismic performances of the new composite shear wall.Comparing with ordinary composite shear wall,shearing capacity of the new composite shear walls is increased by 13.5%?23.2%,lateral stiffness increased by 6.3%?15.7%,ultimate displacement increased by 6.6%?39%,and hysteresis energy consumption increased by 5.86?6.18 times,which indicates that the new composite shear wall is of better seismic performance.When the space of steel reinforced truss is reduced from 200 mm to 150 mm and 100 mm,shearing capacity of the shear wall specimen is enhanced by 3.5% and 9.1%,ductility by 4.85% and 26.49%,and hysteretic energy consumption by 33.8% and 84.1%,respectively,which exhibits that seismic performances of the composite shear wall can be significantly improved by smaller spacing of steel reinforced truss.Longitudinal or horizontal arrangement of steel reinforced truss has insignificant influence on capacity,but the peak displacement,the ultimate displacement,the ductility and the energy consumption are increased by 8.6%,27%,10.6% and 7.6%,hence better ductility and energy consumption can be obtained from composite shear wall with longitudinal arrangement of steel reinforced truss.(2)Finite element simulations of 6 composite shear wall specimens using ABAQUS were compared with experimental results,and simulation results are in good agreement with the test results.Then the effects of parameters,diameter of steel reinforced truss,setting of steel reinforced truss,concrete strength and steel plate thickness on seismic performances of the new composite shear walls were further analyzed.Results show that the increase of thickness of steel plates can significantly improve capacity by 10.7% to 15.38%,but the steel plate should not be too thick to keep the balance between economic performance and seismic performance.Meanwhile when the concrete grade is raised from C30 to C40 and C50,Capacity of the new composite shear wall is enhanced by 13.58% and 35.94% but the ductility decreased by 4.63% and 8.44%.By changing diameter of steel rebar from 4mm to 6mm and 8mm,peak displacement can be increased by 7.69% and 15.38%,and the ultimate displacement by 4.76% and 9.52%,then deformation performance and ductility of the new composite shear wall are improved.Finally,quincuncial arrangement of steel reinforced truss can delay strength degradation,increase ultimate displacement by 3.39%?4.55%,and significantly reduce buckling range of shear wall steel plates.Based on the assumption of flat section,the calculation method of flexural capacity of composite shear walls is accurate to some extent.(3)To comparing seismic performances between the new composite shear wall with steel reinforced truss and the ordinary composite shear wall in a high rise building under rare earthquake scenarios,a frame-core shear wall high-rise building was selected as prototype model,composite shear walls were designed and arranged based on Technical Specification for Steel Plate Shear Walls.Results show that although the top displacement and base shear of the new composite shear wall structure with steel reinforced truss increase by 16.59% and 21.25% maximally,the maximum lateral drift decreased by 5.45%.And the number of damaged shear wall decreased by 88% in the composite shear wall structure with steelreinforced truss,which indicates that seismic damage of core shear wall can be effectively decreased under rare earthquake excitations and seismic resilience high-rise building structure can be greatly sustained.