Exploitation of Acoustic Noise Correlation for Structural HealthMonitoring Applications

摘要

Many recent studies in different domains exploited the ambient noise correlation to retrieve the Green'sfunction between two points. This technique allows a passive characterization of a given medium in the presence of aperfect diffuse field. The aim of this paper is to apply this principle in an aeronautic context. Thus we are looking toexploit the mechanical vibrations in a plane during the flight, to realize a passive structural health monitoring. Indeed, anatural acoustic noise field is produced by engines and aero acoustic effects. That being said, such a field is not spatiallyand temporally perfectly diffused, which yields to imperfect conditions where convergence towards the Green's functionis not ensured. Despite that, in this paper we show that since the obtained information is sensible to the medium state, it isstill exploitable for damage detection. In fact, experimental studies presented in this paper allow verifying two necessaryconditions to the applicability of this technique: the reproducibility of the cross-correlation function, and its potential todetect a defect in the medium. Finally, the influence of the source position on the cross-correlation function is shown.