Experimental And Numerical Simulation Analysis Of Influential Parameters On Seismic Behavior Of Steel Tube-concrete Composite Shear Wall

As a new type of anti-lateral force component,steel tube-concrete composite shear wall has many advantages such as high industrialization,convenient construction and good seismic performance.In order to study the influence parameters of the seismic performance of the new type shear wall,pseudo-static test and ABAQUS finite element numerical simulation analysis were carried out in this paper.The parameters include: axial compression ratio,shear span ratio,section size of steel tube bundle,concrete strength,yield strength of the steel plate,thickness of the steel tube bundle,thickness of shear wal.The main research content and conclusion of this paper is as follows:(1)Five steel tube-concrete composite shear wall are designed.The experiment study of the low cycle reversed load on the model is made.The influence of different parameters on the seismic behavior of steel tube-concrete composite shear wall is study by analyzing seismic performance such as the test phenomena,hysteretic curve,skeleton curve,energy dissipation capacity,shear deformation,stiffness degradation,bearing capacity degradation.The result show: The failure modes of steel tube-concrete composite shear wall is buckling or tearing of steel plate at the bottom of both ends steel tube bundle and concrete crush;The specimen has high bearing capacity and ductility;Changes in concrete strength,yield strength of steel plate and plate thickness of steel tube bundle have certain effects on the bearing capacity and ductility of this kind of shear wall,the influence of plate thickness is particularly obvious.(2)The finite element numerical model of steel tube-concrete composite shear wall was established by using ABAQUS finite element analysis software,and was compared with the test results.The influence of axial compression ratio,shear span ratio,section size of steel tube bundle,concrete strength,yield strength of steel plate,steel tube bundle plate thickness,wall thickness on the seismic behavior of composite shear wall is studied by the verified numerical model.The result show: The bearing capacity and ductility of components under low axial compression ratio increased slightly and then decreased.When the shear span ratio is above 1.0,the shear failure is mainly caused by bending deformation and this kind of shear wall should control shear span ratio to avoid brittle failure.As the section size of steel tube bundle increases,the bearing capacity of the components decreases firstly and then increases due to the change of second moment of area and constraint effect of steel tube bundle.By comparing the influence of concrete strength,yield strength of steel plate and steel plate thickness on bearing capacity,the effect of changing thickness of steel plate is particularly obvious,the effect of changing the concrete strength is the weakest.(3)Based on elastic theory,a simplified calculation method for the stiffness of steel tube-concrete composite shear wall is derived through the theoretical analysis of the experimental phenomena and the data from several groups of tests.The resilience curve before the peak point is preliminarily obtained by the dimensionless fitting of the test data,which is connected with the initial stiffness calculation method in this paper.Based on the plane section assumption and ignoring the restraint effect of steel tube bundle,a simplified calculation method of the bearing capacity of normal section of steel tube-concrete composite shear wall is proposed,according to the calculation method of normal section bearing capacity of reinforced concrete shear wall.