基于MRE的变频TMD竖向振动控制

Vertical Vibration Control of Variable Frequency TMD Based on MRE

目的研发一种基于新型智能材料磁流变弹性体(MRE)的变频调谐质量阻尼器(TMD),为弥补传统TMD的频率不可调提供理论依据.方法研究MRE剪切模量与施加电流之间的关系,采用希尔伯特-黄变换(HHT)和随机减量技术(RDT)相结合的方式对主结构频率进行精确识别,完成了变频TMD对固支梁竖向振动控制的仿真计算,分析了不同质量比对变频TMD和传统TMD减振控制的影响.结果在自行研发的变频TMD中,MRE的剪切模量会随着外加电流的增强而增大,在1.8 A左右接近饱和值.利用HHT和RDT相结合的方法对频率识别方法是精确有效的.固支梁竖向振动的仿真结果表明,变频TMD能够在固支梁频率发生变化时仍保持良好的减振效果,固支梁频率与传统TMD自振频率相差越大,在达到同样减振效果时所需要的变频TMD质量比就越小.结论基于MRE的变频TMD能够实时与主结构频率保持一致,在主结构频率发生改变时仍具备良好的减振效果,并且变频TMD在减小TMD质量比方面也具有较大的优势.

In this paper,a variable frequency tuned mass damper（TMD） based on a newtype of smart material magnetorheological elastomer（MRE） is developed in order to make up for the shortage of traditional TMD,the frequency of which is non-adjustable. The relationship between the shear modulus of MRE and the applied current is studied,the frequency of main structure is accurately identified by the combination of Hilbert Huang Transform（HHT） and random decrement technique（RDT）,the simulation of vertical vibration control of fixed beam with variable frequency TMD is carried out,and the influence of different mass ratio on variable frequency TMD and tradi-tional TMD vibration control is analyzed. The result shows that the shear modulus of MRE increases with the increase of applied current,and it is close to the saturation value when the current reaches about 1. 8 A in the developed variable frequency TMD. The method of frequency identification which is combination of HHT and RDT is accurate and effective. The simulation results of vertical vibration of fixed beam showthat when the frequency of fixed beam changes,variable frequency TMD can also maintain good damping effect,the greater the difference between the frequency of main structure and the natural frequency of TMD is,the smaller the mass ratio of the required variable frequency TMD is under the premise of the same vibration reduction effect. The conclusion of this paper is that the variable frequency TMD based on MRE can keep the same frequency with the main structure in real time and it has good vertical vibration reduction effect in a certain frequency range of the main structure,which has a great advantage in reducing the mass ratio of TMD.