Author : Vaibhav J Suryawanshi and L.S Dhamande

Many rotor dynamic system consist of shaft/rotor elements that are highly liable to transvrse cross sectional cracks due to fatigue. The early detection that can be provided by an effective vibration monitoring and analysis technique is efficient. Two theoretical analyses, global and local asymmetry crack models, are utilized to identify characteristics of the system response that may be directly attributed to the presence of a transverse crack in a rotating shaft. The work reported in this paper is part of an ongoing research on the experimental investigations of the effects of cracks and damages on the integrity of structures, with a view to detect, quantify with the study of some parameter such as critical speed, RMS velocity. As crack initiates and propagates, Critical speed and RMS Velocity changes accordingly and that can be monitored with condition monitoring technique. Therefore the change in Critical speed and RMS Velocity is effective way to identify the crack .In this paper review of these two parameter carried out for effective identification of crack in a Rotor-shaft system.

Keywords: Condition monitoring, Crack Detection, Fracture, Rotating Machinery