Evaluating the Usefulness of Audible Acoustics as a Damage Detection Method in Large Composite Structures

Abstract

There is a continuously increasing demand for non-invasive damage detection methods in aerospace certification testing. This demand is driven by increasing cost effectiveness of these tests by reducing down-time for inspection. This paper aims to evaluate the usefulness of using an audible acoustics camera to detect and locate damage within a relatively large structure under bending load. An acoustic camera is a microphone array of known dimensions, which uses a ‘delay-and-sum’ beamforming numerical model, can detect sources of sound. Under the assumption that damage produces sound, this tool should aid in detecting damage. This method of damage detection was validated against strain gauge, LVDT data, and video recording showing the damage propagation. This paper finds acoustic cameras to have a potential to become a stand-alone detection tool. The authors suggest potential developments to the existing system which could potentially produce a more comprehensive method.