Study On Seismic Behavior Of PEC Column Composite Frame-steel Plate Shear Wall

The Frame-steel shear wall is gradually applied to practical projects due to its good ductility,energy dissipation and high bearing capacity.Under the action of seismic force,the edge members of the Frame-steel plate shear wall are in the state of partial pressure or partial tension,so the stiffness and anti-buckling capability of the frame are highly required.PEC column has high stiffness and bearing capacity,and its combined frame can meet the structural stress requirements.At present,domestic research on PEC column combined frame-steel plate shear wall is still in its initial stage,so it is of engineering significance to study the seismic performance of PEC column combined Frame-Steel plate shear wall.In this paper,three PEC column composite Frame-steel plate shear wall specimens were subjected to low-cycle reciprocating load tests with the thickness of steel plate shear wall and the axial compression ratio of columns as variables.The failure process of each specimen was observed,and the seismic performance indexes such as hysteretic performance,bearing capacity,stiffness degradation,ductility and energy consumption of PEC column composite Frame-steel plate shear wall were analyzed.The results showed that when the thickness of the steel plate was the same,the yield load,peak load and ultimate load of SWFSP-2 were increased by 19.22%,18.79% and 13.35%,respectively,compared with SWFSP-3.Displacement ductility and Angle ductility were improved by 2.45% and 20.1% respectively.The initial stiffness increased by 14.02% and the energy dissipation coefficient E decreased by 13.22%,indicating that the axial compression ratio is one of the main factors affecting the seismic performance of the structure.The bearing capacity reserves of SWFSP-1,SWFSP-2 and SWFSP-3 were 20.55%,23.63% and 24.09% of yield load,respectively.The bearing capacity reserve of the structure is about 20% ~ 25% of the yield load.The initial stiffness of SWFSP-2 was 14.02% higher than that of SWFSP-1.Increasing the axial compression ratio could improve the initial stiffness of the specimen,but reduce the overall energy dissipation performance of the specimen.The stacking effect of shear wall steel plates causes the deflection of the tension zone.The Angle of the tension zone at the top Angle is 30o ~ 42o,the Angle of the middle and upper part and the lower part is 31o ~ 43o,the Angle of the middle tension zone is 39o ~ 44o,and the Angle of the tension zone at the bottom Angle is 36o ~ 44o.The steel plate increases the bearing capacity of the specimen more obviously in the elastic stage and the strengthening stage,especially in the strengthening stage.The specimens can maintain high bearing capacity and good ductility even beyond the limit of the displacement Angle between the elastic-plastic layers and have good seismic performance.On the basis of the experiment,the finite element software ABAQUS was used to establish the three-dimensional parametric model of the specimen,and the finite element analysis and verification and related parameter research were carried out on the PEC column composite Frame-steel plate shear wall,and the influence of column axial compression ratio and steel plate shear wall thickness on the seismic performance of the specimen was compared and analyzed.The results show that the damage of concrete is concentrated in the lower 1/3 of the column,and all of them are located in the left half of the axis of the column.The beam failure range is located within 204~255mm from the beam end,which is consistent with the test failure phenomenon.The yield load of model MN-2 is 30% higher than that of mn-1,and the peak load is 34.32% higher.The yield load of model MN-3 is 12.1% lower than that of MN-1,and the peak load is 11.38% lower.Changing the thickness of steel plate and the stiffness of frame column will affect the bearing capacity of the structure.Among them,the stiffness of the column has a great influence on the curve trend before the peak point,and the thickness of the steel plate has a great influence on the trend of the descending section.