不失稳支撑及不失稳支撑框架结构研究现状

Progress of buckling restrained braces and buckling restrained braced frames

不失稳支撑是一种高效的抗侧力构件,当钢支撑和外包约束构件间的间隙适当且外包构件刚度和强度足够时,钢支撑将以微幅多波失稳的形式承受压力,直到进入受压屈服状态.因此认为,承受压力的该种钢支撑可以避免大幅整体和局部失稳,近似处于轴心受压状态.已有的研究表明设计合理的不失稳支撑和不失稳支撑框架结构均具有稳定的恢复力特性、良好的延性和耗能能力.芯部钢支撑的力学性能、外包构件的刚度和强度、钢支撑和外包构件间的间隙、抗粘结材料的性能及具体的构造措施等因素均可影响不失稳支撑的受力性能.在总结国内外已有的不失稳支撑和应用不失稳支撑的框架-支撑结构研究成果的基础上,提出了为改进其性能和推广应用需进一步研究的问题.

The Buckling Restrained Brace （ BRB）, usually being composed of core steel brace and lateral resisting member, is a kind of effective lateral force resisting members in engineering. The large amplitude of global and local buckling of core steel brace can be avoided because the clearance between core steel brace and outer restraining member is designed appropriately and the restraining member has sufficiently lateral stiffness and strength. As a result, the core steel brace can approximately support axial compressive loading until yielding with higher buckling modes. The BRBs and buckling restrained braced frames （BRBFs） designed properly have been of stable hysteretic character, excellent ductility and energy dissipation capacity according to past relevant research. Lots of factors such as core steel brace mechanical character, flexural stiffness and strength of outer restraining member, clearance between core steel brace and outer restraining member, mechanical behavior of unbonded material and some detail constructions have great effects on the mechanical behavior of the BRBs. In order to improve the overall working behavior of BRBs and BRBFs as well as promote their application, the oroblems need to further exoloring are nroposed.