含有屈曲约束支撑框架的振动台试验研究

Experiment study on shaking table test of steel frame with buckling-restrained braces

通过对含有屈曲约束支撑的框架进行振动台试验,研究了屈曲约束支撑对结构地震反应的减震效果。选用3条天然波和1条人工波进行加载,记录了模型的加速度反应,分析了BRB在试验中的力学性能,并与理论计算值进行了对比,研究了台面输入加速度为0.6g和1.0g时框架底层BRB的滞回曲线。探讨了不同台面输入下输入能量在模型中的分布情况。试验及研究结果表明,当台面输入加速度小于0.6g时,屈曲约束支撑可以为结构提供稳定的侧向刚度;当台面输入加速度大于0.6g时,屈曲约束支撑通过自身塑性变形来吸收能量;当台面输入加速度为1.0g时,屈曲约束支撑可以吸收台面输入的20%~40%的能量。

A buckling-restrained braced frame（BRBF） was tested by shaking table to study the mechanism and efficiency of buckling-restrained brace（BRB） for reducing the seismic responses of the structure.Three natural earthquake waves and one test wave were selected.The accelerations of the model were recorded and the mechanical properties of BRB were analyzed.The hysteresis loops of BRB were studied when the PGA equal to 0.6g and 1.0g,and the energy distribution of the model was discussed.The test results indicate that BRB can provide stable stiffness to the structure when PGA is less than 0.6g and can get into elasto-plastic stage to dissipate the energy when PGA is more than 0.6g.The results also indicate that BRB can absorb（20%～）40% of the whole input energy when PGA reaches 1.0g.