Experimental Study And Numerical Analysis On Seismic Behavior Of Novel Steel-Concrete-Steel Composite Shear Wall

Steel-concrete-steel composite wall(SW)is a novel lateral resisting element composed of outer steel plates and core concrete through shear connectors.It has the advantages of good integrity,large lateral stiffness and good ductility.The research objects of the paper are SCS composite walls with J-hook connection.The experimental tests and numerical analysis were carried out to study and analyze the SW composite walls.The main research contents of this paper are as follows:(1)Six J-hook SWs are designed and conducted.The seismic performance and failure modes were observed under in-plane low cyclic lateral loads.Ductility,stiffness,strenth,energy dissipation and other indicators were analyzed.The effects of J-hooks spacing,steel plate thickness,concrete strength and shear span ratio on the seismic behavior of the composite shear wall were studied.It is found that the steel plate thickness changes and the shear-span ratio have a greater impact on the specimens.The steel plate thickness increased from 4.5mm to 6.0mm,and its f_y and f_u increased by 13%and 16%,respectively.The shear span ratio decreased from 2.0 to 1.0,and its f_y and f_uincreased by 88%and 82%,respectively.(2)Compared with composite walls without boundary columns,five J-hook Steel-concrete-steel composite walls with bundary concrete-filled-steel-tube columns(WBJ)were designed and were tested under low cyclic loading.Study the influence of different J-hooks spacing and axial compression ratios on the seismic behavior of the walls.It is found that the side columns greatly improve the seismic performance of the walls.The energy consumption of the walls with columns are about 3 times of the walls without columns When the J-hooks spacing are increased to 200mm,the f_y and f_u of the specimens are reduced by 14%and 11%,respectively.The increase of the axial pressure ratio reduces the energy consumption of the walls.(3)A numerical model of SWs were established by finite element software ABAQUS.Through the numerical analysis,The failure mode and skeleton curve of the composite walls were analyzed.Comparing with the experimental results,the skeletal curve and peak load are in good agreements,which proves the accuracy of modelings.(4)Based on the experimental verification of the models,the parametric analysis of the WBJs were carried out.The effects of concrete strength,steel plate thickness of the wall,side column steel plate thickness and axial compression ratios on the strength and skeleton curve of the test pieces were analyzed.It is found that the increase of the thickness of the side column steel plate has the most significant improvement on the seismic performance of the specimens.The thickness of the side column steel plate increased from 3mm to 4.5mm,6mm and 7.5mm,the strenth increased by 22%,47%,and 66%,respectively.