分级屈服型金属阻尼器在框架结构中的应用研究

STUDY ON APPLICATION OF GRADED YIELDING METAL DAMPER IN A FRAME STRUCTURE

分级屈服型金属阻尼器具有构造简单、力学性能稳定、耗能强等特点。采用三折线模型作为该阻尼器的力学模型,并对其滞回性能进行模拟,模拟结果与实验结果吻合较好。该模型参数较少且容易确定,可供工程设计使用。对设置该分级屈服型金属阻尼器的框架结构进行小震、中震和大震下的时程分析,对比无控结构和有控结构的层间剪力和层间位移角。结果显示,小震下层间剪力明显减小,中大震作用下设置阻尼器楼层的层间剪力均减小。值得注意的是,中大震作用下首层未设置阻尼器且其层间剪力增大;各级强度地震作用下,有控结构最大层间位移角大幅下降,结构的抗震性能进一步提高。小震作用下分级屈服型金属阻尼器可为结构至少提供1.95%的附加阻尼比,滞回曲线比较饱满且呈双折线;中大震作用下附加阻尼比进一步增加,滞回曲线向外扩大且呈三折线;大震作用下的能量累积曲线显示阻尼器耗散大部分地震能量,有效减轻了结构损伤。

Graded yielding metal dampers have the characteristics of simple structure,stable mechanical properties,high energy consumption,etc.With a three-fold model as the mechanical model,the hysteretic properties of dampers were simulated.The simulation results are in good agreement with experimental results.Only a small number of parameters that can be easily determined are involved,this mode is suitable for engineering design.The time history analysis of the frame structures with graded yielding metal dampers was carried out under minor,medium and major earthquake conditions,and the interlayer shear and interlayer drift of uncontrolled and controlled structures were compared.Results show that the interlayer shear decreased greatly under minor earthquake conditions,and that of floors with dampers decreased under medium and major earthquake conditions.It should be noted that the no dampers were installed in the first floor and the interlayer shear increased;and the maximum interlayer drift of controlled structures decreased greatly under various earthquake conditions,thus further improving the seismic performance of such structures.Under minor earthquake conditions,graded yielding metal dampers can increase the additional damping ratios of structures by at least 1.95%,and the hysteresis curve is full and double-fold.Under medium and major earthquake conditions,the additional damping ratio continues to rise,and the hysteresis curve is expansive and three-fold.Under major earthquake conditions,the energy accumulation curve indicates that most of seismic energy is dissipated by dampers,thereby effectively reducing the structural damage.