On parametrically phase-coupled random harmonic processes

Presents the concept of a parametrically phase-coupled random harmonic process. It is argued that such processes will be present in the vibration signature of a simple mechanical system, and as such would be of interest in the analysis of vibrations for condition-based maintenance. It is shown that conventional higher-order spectral (HOS) techniques reveal only limited features of parametrically phase-coupled processes and would prove of limited utility in the analysis of such signals. A modified second order cumulant spectrum is then introduced, which has the advantage of revealing all parametric phase relationships in the signal of interest. The results of testing using simulated vibration signals are presented.