Seismic Performance Analysis Of Steel Frames With Self-Centering Energy Dissipate Braces

Conventional earthquake-resisting structure mainly depends on plastic failure of the major structure dissipate seismic energy, but it can lead to quite the residual deformation that the structure cannot be reused as well as recovered after the earthquake. Seismic energy dissipation technology has been widely applied in present structure, some additional components or devices are installed in the structure to consume the earthquake energy, in order to protect the main structure not to be destroyed, such as buckling-restrained brace frame, which is unable to deal with the residual deformation in a perfect way. While the self-centering brace has been appreciated by plenty of researchers as a result of its effectiveness to reduce the residual deformation of the structure, it integrates self-centering properties and energy dissipate capacities. This thesis studies the seismic performance of the self-centering energy dissipate brace frames and buckling-restrained brace frames. The main work finished is as follows.(1) This thesis presents the work mechanism and the mechanical behavior of the single-core and dual-core self-centering energy dissipate brace detailedly. Compared with single core device, the axial deformation capacity of the dual-core brace is doubled by using two inner cores and one outer box and by serial axial deformations of two sets of parallel tensioning elements, the dual-core self-centering energy dissipate brace exhibits excellent self-centering property up to a larger story lateral drift in strong earthquake.(2) The finite element analysis software ANSYS is adopted to establish the self-centering energy dissipate brace frame models and buckling-restrained brace frame models.Considering frequently occurred and seldomly occurred earthquake respectively, dynamic response analysis is used to analyze the displacement response of top floor of the structure,the maximum story displacement, inter-story drift, residual deformation and the peak acceleration of the two frames,while compare the hysteresis loop of each kind of brace.(3) In the case of rare earthquake, this thesis studies the effect of each controls parameter on the self-centering energy dissipate brace frame, include the first slope, the second slope,friction focce and post-tension force.To sum up, in this paper, the seismic performance of self-centering energy dissipate brace steel frame and buckling restrained brace steel frame is studied in-depth, which can get some conclusions by analyzing the related performance indexes quantitativly and qualitativly,consdering frequently occurred and seldomly occurred earthquake respectively, these conclusions can provide theoretical basis and technical support for the seismic design ofself-centering energy dissipate brace steel frame and buckling restrained brace steel frame,which has important research value and practical significanc.