Experimental Study On Precast Concrete-encased CFST Composite Shear Walls Subjected To Vertical Tension-horizontal Cyclic Loading

With the continuous transformation and upgrading of the traditional construction industry,the industrialization of construction has become an inevitable trend,and the prefabricated construction is an important way to realize the industrialization of construction.The fabricated shear wall structure is one of the important structural forms of fabricated buildings that meet the economic requirements of high-rise buildings and the development needs of building industrialization,and it has broad application prospects.However,the existing prefabricated shear wall structures at home and abroad have disadvantages such as low integrity and out-of-plane stability,complicated joint connection structure,and weak plastic deformation ability.On the basis of previous research,our group proposed a new type of Precast Concrete-encased high-strength Concrete-filled Steel tube(PCCS)composite shear wall,and the hysteretic behaviour under horizontal cyclic loading and axial tension force of PCCS composite shear wall specimens was studied and the results presented in this paper.The mainly contents are as follows:1)Six PCCS composite shear wall specimens with an aspect ratio of 1.62 were prepared and tested by performing quasi-static test.Considered parameters contain the axially tensile load ratio,the out-of-plane load eccentricity and the high-strength concrete-filled steel tube(CFST)cross-section ratio.Force,deformation and failure process were observed and recorded during the tests.2)The influences of the high-strength CFST cross-section ratio,out-of-plane load eccentricity and axially tensile load ratio are considered in investigation of seismic performance of the PCCS walls,and the failure properties,hysteretic response,deformation and ductility,bearing capacity,stiffness degradation and energy dissipation are analyzed.The experimental results indicate that the PCCS wall specimens under coupled loading fail in a flexural-shear coupling mode,and exhibit good load bearing capacity,full hysteresis loops,good deformation and energy dissipation capacity,large residual stiffness even in a broken state.The shear deformation component has a linear relationship with the totally lateral deformation,which is about 21% of the totally lateral deformation.The average ultimate drift angle and average ductility factor are 1/42 and5.0,respectively,which exhibits good assembly integrity of PCCS walls under vertical tension-horizontal cyclic coupled loading.3)Based on the experimental results,the cross-section analysis model of PCCS composite shear walls were established by XTRACT,and then a comparative analysis between the experimental results and the simulation results was made.4)On the basis of good agreement between the numerical simulation results and the experimental results,the finite element software XTRACT was used to investigate the parameters of the PCCS composite shear wall,the main parameters include the high-strength CFST cross-section ratio,out-of-plane load eccentricity and axially tensile load ratio.The parametric analysis shows that the shear bearing capacity increases with the increase of the CFST cross-section ratio,while the deformation ability decreases.The shear bearing capacity decreases with the increase of the out-of-plane eccentricity and the axial tensile force,and the deformation capacity increases with an appropriate axial tension force,but the out-of-plane load eccentricity has an unfavorable influence on the deformation capacity.