|M.Sc Student||Alloni Aviv|
|Subject||Dynamics of Forced System with Vibro Impact Energy Sink|
|Department||Department of Mechanical Engineering||Supervisor||Professor Oleg Gendelman|
|Full Thesis text|
A Nonlinear Energy Sink (NES) is widely studied as a mean for mitigation of undesired vibrations. The NES is a passive isolation device which is basically composed of a structural element with relatively small mass and relatively weak dissipation, coupled to a primary system and aiming to absorb its energy via essentially nonlinear coupling. The NES is designed to be activated when the energy in the system exceeds a certain threshold. To date a variety of designs of the NESs have been suggested
In this thesis we considered a mitigation of steady-state external forcing by means of a vibro-impact NES. Vibro-impact NES is presented through a simple model of a straight cavity in the primary mass, in which an impacting particle is allowed to move freely. The impacts with the cavity restraints are considered in the framework of a Newton non-elastic model.
In order to solve the system analytically we use the multiple-scales method which enables investigation of "slow" and "super-slow" time scales. We deduced that the system can have two different response regimes that depend on the forcing amplitude. One of these possible regimes is steady-state resonant response; the other is a novel type of chaotic strongly modulated response (CSMR). The latter becomes possible due to special structure of a slow invariant manifold of the problem, possessing only one stable and one unstable branch. These results were confirmed by numeric simulations.