Abstract
Most research into transient vibration during acceleration through a major critical speed has treated a symmetrical system constituted of a disk and a shaft with a circular cross section. In this paper, we discuss experimentally a transient phenomenon in an unsymmetrical rotating shaft system when it passes a major critical speed with a constant angular acceleration. It is elarified that the maximum amplitude is larger than that of a symmetrical system, and the difference depends on the magnitude of the unsymmetry and the angular position of the unbalance. It is also pointed out that the wave form of the amplitude changes extremely depending on the angular position of the unbalance. Experimental and theoretical results are compared.
