Seismic Performance Of Steel Frame Of Self-centering Energy Dissipation Bays

In this paper,the energy dissipation capacity and self -centering characteristics of the super-elastic SMA bolted beam-column joints are applied in the energy dissipation bay to form a steel frame equipped with "self-centering energy dissipation bays".It can not only improve the seismic performance and the recoverable performance of the energy-dissipated bay,reduce the residual deformation under ground motions,but also provide a new idea for the application of SMA bolt beam-column joints in the structure.This paper makes a research on the seismic performance of the steel frame equipped with self-centering energy dissipation bays from two aspects of experimental research and theoretical analysis,the main contents of this research are as follows:(1)The hysteretic behavior of the structural system was discussed based on an experimental work on a prototype connection in the literature.Utilizing single-degree-of-freedom(SDOF)system assigned with the flag-shaped hysteretic characteristics,the energy factors of low-to-medium rise steel frame system with self-centering energy dissipation bay was derived.The energy factors can rationally quantify the peak response demand of the structure following the flag -shaped hysteretic law.The peak response of the structure under ground motion decreases with the reduction of the energy factors.In order to clarify the influence of hysteretic parameters on the energy factor,nonlinear spectral analyses are performed based on the equivalent SDOF systems of the low-to-medium rise steel frame system,and various combinations of structural period,post-yielding stiffness ratio,ductility factor,and the energy ratio are included in the parameter matrix.The dispersion of analysis results is also presented.The analysis results indicate that the energy factors and the dispersion of the energy factors are appreciably influe nced by structural period,post-yielding stiffness ratio and ductility factor,and is less affected by the energy ratio.From the practical point of view,the energy factors of low -to-medium rise steel frame system equipped with self-centering energy dissipation bays should be correlated with the influential hysteresis parameters,so that engineers can easily estimate the energy factors in the structural design or evaluation process.In general,the proposed design equation quantifies the mean energy factor demand of the low-to-medium rise steel frame system with self-centering energy dissipation bay under the near-fault ground motion with good accuracy,and the error is generally within 10%.(2)In order to study the seismic performance of the low-to-medium rise steel frame system equipped with self-centering energy dissipation bays,one 3-layer and two 6-layer steel frame equipped with self-centering energy dissipation bays is designed based on the Code for Seismic Design of Buildings(GB5011 -2016).The modal analysis,elastic time history analysis,static elastic -plastic analysis and dynamic elastic-plastic time history analysis of the structure are carried out,and the vibration mode,self-centering ability,maximum interstorey drift ratio and residual interstorey drift ratio of the structure are calculated.The results show that the maximum interstorey drift ratio of the low-to-medium rise steel frame system equipped with self-centering energy dissipation bays meet specification requirements,the structure have excellent seismic performance and restorability.(3)Through the quasi-static test of "self-centering energy dissipation bays equipped with SMA beam-to-column connections" the excellent seismic performance and great restorability are demonstrated from the structural carrying capacity and stiffness,ductility,energy dissipation capacity and self -centering capability.In order to avoid the influence of friction on the self-centering performance,it is recommended to use rigid joints.