Experimental Comparison of Response for Healthy and Cracked Overhung Rotor System

Online diagnosis of the rotor system has been of great aid for possible detection of crack. In this paper, experimental vibration response of unbalance cracked overhung rotor system with an open crack is compared to the response of a healthy unbalance overhung rotor system for possible indication of the crack presence, due to change in the dynamic response of the cracked rotor system. The experimental modal analysis results have been compared with the finite element results to validate the accuracy of the experimental setup, followed by the comparison of the spectral response for healthy and cracked rotor system. The change in the dynamic behaviour of the cracked rotor system is studied through the waterfall plot and the colour map plot. A noticeable increase of 27.77% in response amplitude for crack overhung rotor system compared to that of healthy overhung rotor system is observed with unbalance provided to disc. The changes seen in both plots can be utilized for the indication of crack presence in the rotor system.