THE NONSTATIONARY TRANSITION THROUGH RESONANCE

This paper considers the resonant behavior of a mechanical oscillator during a linear frequency sweep. Both numerical and experimental resul ts are presented. The experimental system consisting of a track in the shape of a potential energy surfaces has been used to highlight other types of nonlinear behavior and is here adapted so that the forcing f requency can be evolved continuously in time. The classic linear oscil lator (with a parabolic potential well) is used as an introduction to illustrate basic features of the experiment and its response. Then, a track with a double well is used to assess nonstationary frequency eff ects on certain nonlinear characteristics, specifically amplitude jump s and flip bifurcations.