Improved inerter-based vibration absorbers

Tuned vibration absorber for suppression of hand-arm vibration in electric grass trimmer

https://ira.lib.polyu.edu.hk/bitstream/10397/5192/3/paper_tso_Revised_1_1.pdf

Suppression of random vibration in flexible structures using a hybrid vibration absorber

A non-traditional dynamic vibration absorber is proposed for the minimization of maximum vibration velocity response of a vibrating structure. Unlike the traditional damped absorber configuration, the proposed absorber has a linear viscous damper connecting the absorber mass directly to the ground instead of the main mass. Optimum parameters of the proposed absorber are derived based on the fixed-point theory for minimizing the maximum vibration velocity response of a single-degree-of-freedom system under harmonic excitation. The extent of reduction in maximum vibration velocity response of the primary system when using the traditional dynamic absorber is compared with that using the proposed one. Under the optimum tuning condition of the absorbers, it is proved analytically that the proposed absorber provides a greater reduction in maximum vibration velocity response of the primary system than the traditional absorber.

Design of a non-traditional dynamic vibration absorber.

Vibration suppression in harmonically forced viscously damped systems is considered using a new vibration absorber setup. The absorber is placed between the primary system and the supporting ground. The optimal absorber parameters are obtained with the aim of minimizing the maximum of the primary system frequency response. For a given damping ratio of the primary system and mass ratio of the system, the optimal stiffness and damping ratios of the absorber are calculated numerically. Two different numerical approaches are used in solving the problem; the first is based on the genetic algorithm technique and the second on the downhill simplex method. It is shown that an optimal mass ratio exists and it is calculated along with the corresponding absorber parameters for a range of the primary system damping ratio. The utmost optimal parameters associated with the optimal mass ratios are tabulated to be used for the design of such absorbers. The absorber efficiency is discussed and it is shown that this absorb...

Design of a vibration absorber for harmonically forced damped systems

One drawback of the traditional dynamic vibration absorber is that it can only absorb the vibration of a continuous structure such as a beam at the point to which it is attached. In this article, it is proved that if damping in a vibrating beam structure is negligible, a translational dynamic absorber used in combination with a rotational dynamic absorber can absorb both translational and rotational motions for part of a vibrating beam subjected to harmonic excitation. An analytical model based on Euler-Bernoulli beam theory is constructed for a beam under partially distributed loading, and it is proved theoretically that the two absorbers can not only absorb vibration in the unforced portion of the beam, but can also isolate vibration in the portion under direct excitation. Two numerical examples are given for illustration, and some useful applications of the absorbers are discussed.

Y. L. Cheung

Papers

Isolation of bending vibration in a beam structure with a translational vibration absorber and a rotational vibration absorber