一种新型自复位防屈曲支撑的拟静力试验

为了控制安装有传统防屈曲支撑的结构在大地震作用下产生的最大变形及残余变形,提出一种新型防屈曲支撑——自复位防屈曲支撑(SCBRB).对其构造及工作和复位原理进行了详细说明.在此基础上,给出复位材料的预应力及变形需求等关键参数的设计方法,并实现了这种支撑.该支撑综合了防屈曲支撑及自复位体系的优点.拟静力试验研究结果表明预应力成功地接设计值施加并且完好保持是决定复位效果的关键因素,预应力不足则其复位效果变差,预应力与耗能内芯屈服力之比大干等于1.3时即可保证完全复位.传统防屈曲支撑与自复位防屈曲支撑拟静力试验的对比结果表明:此类支撑基本消除了纯防屈曲支撑的残余变形,具有良好的复位效果.

Cyclic tests of novel self-centering buckling-restrained brace

An innovative self-centering energy dissipation device called self-centering buckling-restrained brace(SCBRB) is put forward to control maximum and residual drift of steel frame structures subjected to severe earthquakes.The configuration and mechanics of this new system are explained.The design method of primary factors including prestressing force and deformation demands of prestressing tendons is outlined,and one realization of the system,which combines the merits of both self-centering devices and buckling restrained braces(BRBs),is presented.From the cyclic test,it is found that the implementation and maintaining of the prestressing force in the prestressing tendons dominates the re-centering capacity of SCBRB.Too much loss of prestressing force weakens the self-centering capacity.The ratio between the total pretension force of the tendons and the total yield force of energy dissipation bars should be larger than 1.3 to ensure fully self-centering.Results from the cyclic tests of SCBRBs and BRBs confirm the expected re-centering capacity of SCBRBs which eliminates main residual deformations.