Processing for Improved Spectral Analysis



Eric Bechhoefer Brandon Van Hecke David He


The Fast Fourier Transform (FFT) is the workhorse of condition monitoring analysis. The FFTs’ assumption of stationarity is often violated in rotating machinery. Even in a six second acquisition on a wind turbine, the shaft speed can change by 5%. For Shaft and Gear analysis, this is mitigated through the use of the time synchronous average. For general spectrum analysis, or bearing envelope analysis, there is no such mitigation: one hopes that the effect of variation in shaft speed is small. Presented is a time synchronous resampling algorithm which corrects for variation in shaft speed, preserving the assumption of stationarity. This allows for improved spectral analysis, such as used in bearing fault detection. This is demonstrated on a real world-bearing fault.

How to Cite

Bechhoefer, E. ., Van Hecke, B. ., & He, D. . (2013). Processing for Improved Spectral Analysis. Annual Conference of the PHM Society, 5(1).
Abstract 42 | PDF Downloads 17



Spectral Analysis, Bearing Analysis, Stationarity, FFT, Resampling

ISO 10816 Vibration Severity Standards.

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