Use of vibroacoustical signal in detecting early stages of failures

An understanding of vibroacoustic signal is required for the robust and more effective detection of early stage failure. In the paper the possibility and method of time varying vibration decomposition are discussed. It is shown that analysing the coupling between the structure’s components changes from linear to nonlinear or to other kind of nonlinearity together with intermodulation phenomena can be used as measure in structural health monitoring. In addition on an analytical connection is investigated between the tracking method and the physics of the kinematic contact process based on the idea of higher-order spectra analysis, bispectral analysis specially.