Analysis of whirling speed and Evaluation of self-excited motion of the rotating shaft

In any rotating element, when the frequency of the rotating element equals the natural frequency of transverse vibration, then that speed is called critical speed of the rotating element. The measurement of this critical speed and related whirling motion is one of the important problems to be addressed by design and maintenance engineers. Also the whirling of shaft and its motion comes under the category of self-excited motion i.e. self-excited vibration in which the exciting forces and inducing motion are controlled by the motion itself