Parameter study for Structural Health Monitoring based on ambient noise cross‐correlation.

The possibility of performing Structural Health Monitoring in aeronautic structures using ambient noise cross‐correlation techniques has been investigated in previous works. The applicability of such methods has been validated by checking the reproducibility and the potential in terms of damage detection. In this paper, a more detailed description of the acoustic phenomena involved is given. The influence of the different parameters (source characteristics, sensors and damage positions, etc.) on the cross‐correlation function has been studied. A theoretic study is presented and used to develop a simple simulation tool based on multipath reflections of ballistic waves. The simulated results have been successfully compared to finite element results in simple cases. This tool is then exploited to characterize and quantify the influence of the significant parameters. Finally, some optimization solutions of the technique are proposed, and experimentally validated.