| In high-rise buildings,the composite shear wall can increase component ductility and seismic performance because of lower weight,increased bearing capacity and increased energy dissipation capacity.It can provide an effective solution to balance the bearing capacity and seismic performance in high-rise building.However,qualitative analysis is currently used to study the seismic performance of this kind of composite shear wall.The mechanism in steel plate and concrete is unclear,and there is no simplified analysis model based on mechanism.The composite shear wall is seriously restricted in the engineering application.In order to solve the above problems,the seismic performance of multi-cavity composite shear wall with double steel plates and infilled concrete is researched using experimental study,numerical simulation and theoretical analysis.Above all,the impact of seismic performance including the number of cavities and wall thickness is determined,and the failure phenomenon and mechanism of the steel plate and concrete are investigated.Then,the influence laws of parameters on ultimate bearing capacity,elastic stiffness and ductility are quantified and the design formulas of composite shear wall are provided.Finally,the influence of key structural forms on seismic performance is evaluated,and two different simplified design models are established.Therefore,the main research contents of this paper are as follows:Experimental study on seismic performance of multi-cavity composite shear wall with double steel plates and infilled concrete is conducted.Based on the simulation analysis of seismic performance of typical high-rise buildings,the values of common axial compression ratio and shear span ratio of composite shear wall are determined.The cyclic lateral loading experiments of 15 multi-cavity double steel plate concrete composite shear walls are designed and completed,and the failure modes of composite shear walls are determined.The effects of wall thickness and cavity number on basic seismic performance of composite shear walls are investigated,including hysteretic curve,ultimate bearing capacity,strength degradation,stiffness and stiffness degradation and energy dissipation capacity.Numerical simulation on seismic performance of multi-cavity composite shear wall with double steel plates and infilled concrete is conducted.By comparing the failure phenomenon and hysteretic performance of experimental and numerical simulation,the numerical analysis model is verified and determined.To analyze the distribution of shear force in composite shear wall under different displacements,the horizontal shear forces of steel plate and concrete at different places are extracted.The stress states of steel plate and concrete are investigated under different displacements.The bending shear failure of the composite shear wall is obtained,with the failure phenomenon includes tensile and compression failure at the corner,shear failure in the middle area and crushed concrete.The force transmission path of the web plate and concrete are investigated,and the mechanism of the middle web plate under shear,the corner web plate under tension and the concrete under compression and shear in composite shear wall is revealed.The calculation of the ultimate bearing capacity,yield bearing capacity and stiffness in every states in the multi-cavity composite shear wall with double steel plates and infilled concrete are proposed.The effects of wall thickness,steel ratio,shear-span ratio,axial compression ratio,concrete strength,steel strength and length-width ratio of channel on the seismic performance of composite shear wall are investigated.The most effective parameters are determined based on the ratio of seismic performance improvement.The formulas for determining the ultimate bearing capacity,yield bearing capacity,elastic stiffness,secant stiffness at yield state and stiffening stiffness of composite shear wall are proposed based on the test and parametric analysis results.The influence of key structural forms in multi-cavity composite shear wall with double steel plates and infilled concrete is studied.The failure modes of composite shear walls under different stress states are analyzed,and the formulas for calculating critical stress of steel plate and stud spacing are established under axial compression,shear and combination of compression and shear.The optimal construction measures for assembling the stiffened plate of composite shear wall are proposed,and the seismic performance features are investigated.The construction measures of the end restraint members of composite shear wall are presented,and the influence law of seismic performance on the wall is explored.The simplified model and restoring force model of multi-cavity composite shear wall with double steel plates and infilled concrete are established.Based on mechanism analysis,the simplified model called Beam-Shell model is proposed,which can accurately simulate test results and forecast the ultimate bearing capacity of walls with different sections.The Beam-Shell model can partially reflect the force distribution of the web plate and concrete,as well as the stress state of wall.The restoring force model is developed,which can be used in a more simple spring element model,and the calculation efficiency is good,which can provide an useful reference for engineering seismic design. |
