Study On Seismic Behavior Of Composite Shear Wall Confined By The Concrete Filled Steel Tube Out Of Plane

Since the 21st century,the process of modernization and urbanization has been accelerated and the market of construction continues thrive.Recently,the prefabricated building has been increasingly applied,and the composed shear wall has also received much more attention.In this paper,the model verification of the experiment specimen in the existing research is carried out to prove the rationality and correctness of the modeling method,material constitutive and algorithm.Then it comes to the composite shear wall constrained by the concrete-filled steel tube(referred to as CSW-CFST).It’s seismic performance is simulated and analyzed in the out of plane direction.The influence of axial compression ratio,steel pipe width and thickness,high-thickness ratio and shear-span ratio on seismic performance is analyzed based on OpenSees simulation.The conclusions are as follows:(1)The results show that the fitting effect of concrete 04 on the peak bearing capacity is better.The positive fitting degree of the curve is better than the negative and the curve rises slightly higher than the experimental results in the early stage.By comparing the skeleton curve,the peak displacement is relatively close.The early curve trend is consistent,and the positive error is not more than 15%.Generally speaking,the verification results are ideal,and the modeling method and constitutive model can be used for the next out of plane seismic performance analysis.(2)Compared with the specimens of cast-in-place concealed columns and specimens without edge restraint,the out of plane bearing capacity of CSW-CFST is greatly improved,and the hysteretic circle is fuller.The bearing capacity and stiffness of the specimens increase with the increase of the width and thickness of the steel pipe,and the pinching effect of curve is weakened with the increase of width and thickness.(3)Under the same axial compression ratio and steel ratio,with the increase of wall thickness,the hysteresis loop shows an obvious trend of fullness;the out of plane bearing capacity,energy dissipation capacity and stiffness of the specimens increases The change of wall height has a weak effect on the peak bearing capacity.The shear span ratio has little effect on specimenAccording to the current code,a theoretical model for calculating the peak bearing capacity is proposed,and the comparation is made with the simulation results.In general,the error is within a reasonable range but still needs to be corrected by subsequent tests.In addition,the dynamic time-history analysis of a three-story frame is carried out mainly analyzes whether it must consider the effects of the shear wall out of plane to its seismic response in the frame structure.It is found that adding out of plane shear walls can weaken the seismic response of the frame to a certain extent,so the out of plane shear walls can provide certain lateral resistance capacity,which can be considered in the dynamic analysis.