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DINAME2019
DINAME2019
Rotor Crack Identification Based on Mode Shape and Derivative Order Using Combination Resonances
Submission Author:
Izabela Batista da Silva , MG , Brazil
Co-Authors:
Izabela Batista da Silva, Paulo Costa Porto de Figueiredo Barbosa, Aldemir Ap Cavalini Jr, Valder Steffen Jr, Nicolò Bachschmid
Presenter: Izabela Batista da Silva
doi://10.26678/ABCM.DINAME2019.DIN2019-0145
Abstract
Several works on crack detection techniques dedicated to rotating machines have been proposed along the years. Previously, the second order derivative of the shaft mode shapes was used for crack identification purposes revealing satisfactory results. In this case, the second derivative of both the healthy and the faulty rotor mode shapes are compared. Any deviation on the resulting curves is interpreted as the crack location. However, the vibration responses of the rotor must be measured for many positions along the shaft. Additionally, good results are obtained only if the rotor operates close to one of its critical speed. Recently, a crack identification methodology based on a nonlinear approach was proposed. This technique uses external applied diagnostic forces at specific frequencies attaining combination resonances in the spectral responses of the flexible shaft with crack. In this context, the present work proposes to use both methodologies to identify the presence and the location of cracks in a rotating machine. The advantage of this technique is that the shaft can operate in its normal condition, which is usually far away from any critical speed.
Keywords
rotating machines, crack detection, modal shapes, combination resonances
