Vera S., Febbo M.

The dynamic vibration absorbers (DVA) are devices used very commonly for vibration suppression. In this work a theoretical analysis of a dynamic vibration absorber attached to a viscously damped beam is presented. The DVA is composed by several one degree of freedom systems, its principal advantage is that it is possible control several modes of the principal structure simultaneously. A new criterion is introduced to optimize the parameters of the device with the objective of reducing the motion of certain points on the beam. The mathematical model is based on the Assumed-Modes Method making use of Lagrange’s multipliers to contemplate the constrains introduced by the absorber and the optimization is performed by means of the “simulated annealing” technique. The developed method consists on minimizing the amplitude of vibration in predetermined points of the beam considering a broadband attenuation and using Den Hartog’s ideas. Cases studies show the superior performance of the new method relative to classical techniques for determining absorber parameters. In particular the influence of position of the DVA relative to the point where the motion is desired to be reduced is attempted.