钢棒防屈曲支撑受力性能研究

Mechanical behavior of steel bar buckling restrained braces

研发了一种钢棒防屈曲支撑(简称SBBRB),使得钢棒不仅能承受拉力,也可承受压力,从而提高钢棒的受力性能。通过对SBBRB足尺试件进行低周往复加载试验,研究其受力性能、破坏形态和耗能能力,并对支撑的应变和位移历程进行了全过程监测;采用ABAQUS分析软件建立了钢棒防屈曲支撑的有限元模型,并对试验工况进行模拟。研究结果表明:通过将钢棒内置于钢管套筒内,可使钢棒能够承受压力,试验得到的SBBRB受压极限承载力是钢棒受压临界荷载计算值的10倍左右;合理设计的SBBRB的钢棒屈服段在受拉和受压状态下均能充分屈服而不会发生支撑构件的屈曲破坏,具有较好的延性以及稳定的累积滞回耗能特性,在破坏之前滞回曲线始终饱满和稳定;可以通过监测钢棒受力,预先采取措施,从而保证结构安全;ABAQUS有限元分析结果与SBBRB试件按照预定加载制度进行加载的试验滞回曲线吻合较好,可为后续相关研究提供参考。

By developing a new type of steel bar buckling restrained brace(SBBRB),the steel bar can not only withstand tensile forces,but also withstand compressive forces,thus improving the mechanical performance of the steel bar.Based on the quasi-static test of SBBRB specimen,the mechanical properties,failure mode,and energy dissipation capacity of the SBBRB were studied.The whole process of the strain and displacement of the SBBRB was monitored.A finite element model of SBBRB was established by using ABAQUS,and the typical test case was simulated.The results shows that:by placing the steel bar inside the pipe sleeve,the steel bar can withstand compressive forces,and the ultimate compressive bearing capacity of the SBBRB is about 10 times of the calculated critical load of steel bar under compression;the section of the steel bar can be fully yielded without the buckling failure of the brace member under both tensile and compressive forces;it has good ductility and very stable cumulative hysteretic energy dissipation characteristics,and the hysteresis curve is always full and stable before failure;the stress of the steel bar can be monitored and predicted beforehand,so that the safety of the structure is ensured;the experimental hysteresis curves of the test specimen loaded according to the predetermined loading system are in good agreement with the calculation results by using ABAQUS and can give a reference to future research.