自调频调谐质量阻尼器及其减振性能试验

Experimental Study of Effect of Controlling Vibration of Self-Adjustable Tuned Mass Damper

摘要:

为了改善调谐质量阻尼器（TMD）对频率调谐敏感和使用过程中TMD的频率难以调节的缺陷，利用可调节质量的箱体代替TMD的质量块，并附加上伺服控制系统和驱动装置，即为自调频TMD.在特定的外界激励作用下，伺服控制系统能够自发地启动驱动装置改变TMD的质量，调节TMD频率至控制结构频率附近.通过对比自振频率偏离TMD频率的单自由度简支桥梁模型，在TMD启动变频率调节前、后两种情况下的自由振动和受迫振动，以等效阻尼比、加速度峰值和均方根值等作为评价指标，测试了该自调频TMD对原TMD的改良效果.结果表明：变频率调节有较好的收敛性，且相比启动变频率调节前，启动后能提高模型结构的等效阻尼比；多种人行荷载工况下，相比启动变频率调节前，启动后均能提高减振率.

关键词:自调频调谐质量阻尼器; 被动控制; 自由衰减试验; 受迫振动试验; 响应评估

Abstract:

In order to solve the problem of mistuing of tuned mass damper (TMD) and overcome the difficulty to adjust the frequency of TMD during normal using, a selfadjusting TMD was proposed. The selfadjustable TMD was generated by a tank instead of solid mass, using a servo control system to start the drive to change the mass of (TMD) and spontaneously adjust the frequency of TMD to main structure near the natural frequency of vibration, under the special harmonic excitation. The vibration reduction effects with or without this selfadjustable device under freedom vibration and forced vibration were set to investigate the effect on improving the previous TMD based on the equivalent damping ratio, the peak value of acceleration, and rootmeansquare. The results indicate that the selfadjustable TMD has a good convergence and could increase the equivalent damping ratio of the structure. The selfadjustable TMD has good vibration tuned effects for the various excitation conditions.

Key words:self-adjustable TMD; passive control; freedom vibration test; forced vibration test; response evaluation