Experimental Study Of The Energy Consumption Performance Of Rectangle Section Buckling-restrained Brace Made Of GB Q235Steel In China

Because the concentrically braced frame can offer older resisting stiffness tostructure, it was widely used in the seismic area. But in the Northridge earthquake of1994and the Kobe earth-quake of1995, a large amount of destruction appeared in thebuilding of this kind of system. Studies have suggested, because of brace buckling early,the strength of structure is dropped. Therefore, the experts and the scholars propose theBuckling-Restrained Brace (abbreviated as BRB) which will yield and consume energyfirstly instead of buckling. This system is a large amount of adopt already in Japan andU.S.A., demonstrates good anti-seismic performance. In china, there are more and moreresearchers into the BRB to support research.Six specimens with three steel categories, three kinds of cross section shape andtwo kinds of the irrigation actual material method are tested that effect for BRBs energydissipation and seismic performance. Based on the under cyclic low-cycle load theexperimental, it was researched that the mechanical behavior and seismic performancein the aspects such as loading capacity, hysteretic performance, ductility, energydissipation, degradation of strength and stiffness, equivalent viscous damping ratio. Theexperimental results show that the structure of this new BRB is applicable and all thehysteretic curves are stable and plump; Both core material properties and the irrigationactual material have significant effects on the energy dissipation capacity of the BRBs.Then the work principle in stability of BRB are analyzed, and the related formulas arederived, including requirements of overall stability and core element stability. Restoring force model for BRB was received on the test, and the comparison of measured andtheoretical mechanics characteristics of BRB. The test results indicate that the measuredmechanics characteristics of BRB agree well with theoretical results and the energydissipation behavior of BRB is stable. This new type of BRB can meet the requests ofexisting codes and reach the standard of application.