Design of Multiple-level Parallel Dynamic Vibration Absorber Based on the Flexible Beam

Abstract

The amplitude magnification factor dimensionless expression is gained through modeling multi-level parallel dynamic vibration absorber mathematical model combined with the impedance of elastic foundation based on the assumption of elastic foundation. It is found that the influence of elastic foundation on the main system cannot be ignored and the necessity is proposed to optimize the multiple-level parallel system combining the advantage of decaying vibration. The influence of the distance u between the connection and the end on the main system is also analyzed: the less u, the smaller the influence of the beam elastic vibration on the main system. The first frequency will not occur coupling vibration with the main system when u  1m, and u=2m has the most influence. The numerical optimization method is used to design the parameters of 2-grade parallel and 4-grade parallel system. The result shows: the result of rigid connects system is not applicable to the elastic system. It will effectively reduce the influence of the beam elastic vibration on the primary system through optimizing the whole system. At last, the connection dynamic stiffness is researched, it shows that the first natural frequency of beam has no effect on the first three nature frequencies when 40 d K  k , the influence can be neglected when 70 d K  k .