THE INTERPRETATION OF BISPECTRA OF VIBRATION SIGNALS .2. EXPERIMENTALRESULTS AND APPLICATIONS

Bispectral analysis is emerging as a new powerful technique in signal processing, offering insight into non-linear coupling between frequenc ies and having potential applications in many areas where traditional linear (i.e. power spectral) analysis provides insufficient informatio n. However, it is more difficult to interpret bispectral features than power spectral features, and this has hindered the applications of th e theory. In this paper a normalised bispectral measure is used in the analysis of vibration signals containing periodic components and nois e. Part I of the paper presented bispectral features associated with v arious signal types, and discussed practical matters regarding the cho ice of sampling rate. In Part II these theoretical results are used to interpret the bispectra of data collected from a variety of vibration sources, showing that there is potential for using these measures for machine condition monitoring.