Test Study On Mechanical Property Of Double-Tube Buckling-Restrained Braces

Earthquake is natural disaster that threatens people's life and property, to minimize the influence of earthquake to the human, after many years of experiments and study the architectural engineers and scientists initiate the concept of BRB (Buckling-Restrained Braces).BRB is it is one kind of axially loaded frame member that will yield in tension and compression but will not buckle. Its hysteresis curve is full, so it has good energy-consuming capability. Replacing the ordinary steel braces by the BRB in the framework can not long improve the rigidity but also the ductility of the framework, so it can absorb the earthquake energy effectively, and protect the structural parts like beams and columns, which means to make sure that their bearing is within their resilience limit, so the disaster of earthquake is minimized effectively.Because of too much variety of the patterns and materials, many factors should be considered excessively in the design, therefore the quality and the accuracy can not be easily controlled in the process of the fabrication and the installation. The essay brought forward double-tube buckling-restrained brace which has brand new intersecting surface.Firstly, this essay deduced the critical load formula for double-tube buckling-restrained brace and brought forward calculation method and simplified calculation formula ensuring the monolithic stability of double-tube buckling-restrained brace according to the property of the steels in our own country. Then the correctness of the conclusions above-mentioned was tested through the energy method. The simplified calculation formula ensuring the monolithic stability of double-tube buckling-restrained brace afford theoretical support for the experiment.Secondly, double-tube buckling-restrained brace was designed based on the theory and the mechanical properties of double-tube buckling-restrained brace were studied under Low-cyclic Reversed Loading test.In the end, the experiment data was arranged and the hysteresis curve of double-tube buckling-restrained brace was drawn. The conclusion that double-tube buckling-restrained brace is one kind of component which can dissipate seismic energy well was obtained through analyses. The author also gave some suggestion related to the design of double-tube buckling-restrained brace.