Vibration Localization in Rotating Shafts, Part 2: Experiment

This paper presents an experimental study of vibration localization in single-span, flexible, rotating shafts. It was shown in a companion paper (Part I) that a noncircular cross-section of the rotating shaft, leading to dissimilar lateral moments of inertia, can introduce disorder. Internal coupling between the principal directions of vibration is provided by the rotational speed through the gyroscopic moments. It is experimentally demonstrated here that directional vibration localization can occur for appropriate combinations of disorder and coupling. The steady state response, due to mass unbalance, of a simply supported rotating shaft is considered. It is shown that disorder and gyroscopic coupling lead to directional vibration localization; i.e., larger vibration amplitudes in one of the two orthogonal principal directions of the shaft cross section.