Applicaton of Modal Filtration for Damage Detection of Rotating Shaft

Abstract

The paper describes a modification of the method which uses the modal filtration for damage detection [11] to make it suitable for rotating machinery. Authors have formulated a diagnostic procedure which is based on the output only data measured during object operation. The measurement can be performed both by accelerometers placed on the shaft bearing cages and directly on the shaft with use of the laser vibrometer. The procedure was verified on the experimental data. For the experimental verification authors have used the laboratory stand which allows simulation of different faults.

Experimental verification of the damage localization procedure based on modal filtering

“…The main idea of the method was introduced in reference. 8 Its extension is presented in this article. This extension consists of a better recognition pattern introduction -damage index (DI).…”

“…The method described above was extended to damage localization in 2008 by Mendrok and Uhl. 8 The idea behind extension of the method by adding damage localization is based on the fact that damage, in most cases, only disturbs the mode shapes locally. That is why many methods of damage localization use mode shapes as input data.…”

Spatial Filter for Operational Deflection Shape Component Filtration

“…However, this approach frequently does not provide the desired results, especially in the rotating machinery, where the harmonic components dominate in the response spectrum. The trial of this problem solution has been presented in the paper [10], but approach presented there, requires a human interaction and because of that its application in SHM is limited. In this paper authors propose a new formulation of spatial filter that enables a filtration of operational deflection shapes instead of mode shapes.…”