Analysis of the Synchronous Response of Rotor Components by Wavelet Transform and Wavelet Probing

Abstract

The measured synchronous response of rotor components may be analyzed with two objectives. On the one hand, the estimation of the response amplitude is necessary for structural calculations such as the assessment of the low-cycle fatigue safety margin. On the other hand, it is used for system identification purpose with particular interest for damping. Both these tasks can be carried out efficiently and accurately using the time-frequency analysis (TFA) based on the continuous wavelet transform (WT). A major issue that limits a wide use of this tool is the lack of criteria to guide the analyst to a proper choice of the parameters involved in the wavelet transform. This paper discusses this problem from a theoretical and practical point of view and provides a criterion valid for the analysis of the response during resonance crossings.