Using diffuse vibrations interferometry for structural health monitoring of high-speed naval ships
It has been demonstrated theoretically and experimentally that an estimate of the Impulse response (or Green's function) between two receivers can be obtained from the long-time average of the cross-correlation of diffuse vibrations (or ambient noise) recorded at these two receivers in various environments and frequency ranges of interest: ultrasonics, underwater acoustics, and seismology. Identical deterministic time signatures emerge from the noise cross-correlation function based on robust and simple signal processing between passive sensors. This Diffuse Vibration Interferometry (DVI) technique provides a means for structural monitoring using the ambient structure-borne noise only, without the use of active sources. The resulting coherent arrivals obtained from DVI can then be used to estimate and monitor the structural response of the tested structure. We present experimental results using low frequency random vibration data collected on high-speed Navy ship in the course of dedicated rough water trials when structural measurements took place during high sea state and the ship encountered strong wave impact loading.
