基于自复位变摩擦阻尼器的结构减震控制

Seismic Response Control of Civil Structures with Self-centering Variable Friction Dampers

目的针对常摩擦力摩擦阻尼器不能根据结构反应实时调整滑动摩擦力、导致减振效果不稳定的问题,研发一种自复位变摩擦阻尼器.方法基于库仑摩擦定律建立自复位变摩擦阻尼器的恢复力模型,通过对设置以及未设置阻尼器的结构分别进行确定性及随机地震反应分析,研究该阻尼器的减振效果.结果确定性地震动作用下,自复位变摩擦阻尼器能够有效减小结构的层间位移反应,而绝对加速度反应通常有所增大;随机地震动作用下,自复位变摩擦阻尼器能明显减小无控时层间位移较大楼层的位移反应,多数楼层绝对加速度均方根值的均值和标准差有所减小,而楼层绝对加速度峰值大多增大.结论自复位变摩擦阻尼器能明显降低结构的位移反应,且位移控制效果基本上不随输入地震动加速度峰值的变化而改变,但受控结构的加速度反应通常较无控结构有一定增大.

The sliding friction force of traditional constant-friction-force dampers cannot be adjusted in real time according to structural responses,resulting in unstable vibration control effect.In this paper,a novel self-centering variable friction damper(SCVFD)is developed,and then the hysteretic model of this damper is established based on the Coulomb's law.To investigate the seismic control effect of SCVFDs,seismic response analyses of structures with and without SCVFDs subjected to deterministic and random earthquake ground motions are carried out respectively.Numerical results show that the SCVFDs can effectively reduce inter-story drifts of the controlled structure subjected to deterministic ground motions,while the absolute accelerations of structures with control are usually greater than those without control.In the case of random seismic excitation,the SCVFDs can significantly mitigate displacement responses of the stories where the inter-story drifts are relatively large.Additionally,the mean and standard deviation of RMS absolute accelerations of most floors are reduced while the opposite is true for the peak absolute accelerations.