Study On Seismic Performance Of Two Story CFS-steel Frame Hybrid Structure

In this paper,experimental study and finite element analysis are used to study the seismic performance of the CFS-steel frame hybrid structure,and the reasonable design ratio of the upper and lower stiffness ratio of the cold-formed thin-walled steel composite wall steel frame hybrid structure is proposed.By controlling the upper and lower stiffness ratio,the seismic performance of the structure is optimized.The specific research contents are as follows:(1)Four full-scale cold-formed thin-walled steel composite wall steel frame hybrid structures were tested under horizontal loading.The influence of the ratio of upper and lower stiffness on the seismic performance of the hybrid structure was investigated.The failure modes of the hybrid structure were summarized.The load displacement curves of the specimens were compared.The bearing capacity of the wall,story displacement angle,ductility,stiffness degradation,strength degradation and energy dissipation were analyzed The influence of force.The results show that the composite wall is mainly damaged by the self tapping screw connection at the edge of the cold-formed thin-walled steel composite wall panel and the buckling failure of the side column and the middle column at the top and bottom of the column.(2)ABAQUS finite element software is used to simulate the cold-formed thin-walled steel composite wall steel frame hybrid structure.S4 R element is selected to simulate the light steel keel and OSB panel,C3D8 R element is selected to simulate steel frame.Two connectors in series are used to simulate the connection between the connection panel and the self tapping screw of the light steel keel.The model can simulate the constitutive relationship of the self tapping screw and effectively simulate the pinch effect of the self tapping screw under low cyclic repeated load.This kind of interaction is used to simulate the self tapping screw in the finite element model of hybrid structure,and the horizontal hysteretic load is applied to the hybrid structure.The results of the finite element calculation are compared with the failure characteristics,hysteretic curve and bearing capacity of the test,and all fit well,which verifies the correctness of the finite element analysis method in this paper.(3)After the finite element analysis method of the mixed structure verified by the test data,the parameters of the mixed structure with different upper and lower stiffness ratio are analyzed to study the influence of the upper and lower stiffness ratio on the shear capacity of the wall.On the basis of experimental research and finite element variable parameter analysis,the design range of upper and lower stiffness ratio of cold-formed thin-walled steel composite wall steel frame hybrid structure is proposed,and the stiffness reduction factor of cold-formed thin-walled steel composite wall is proposed to modify the initial stiffness design value of composite wall.