Acoustic Wave Propagation and Scattering for Fault Detection in Honeycomb Composite Panels

Abstract

This paper reports on an effort to develop and demonstrate structural health monitoring—specifically, fault detection and localization—algorithms for composite sandwich panels. The test artifact was a small panel consisting of an aluminum honeycomb core sandwiched between two carbon-fiber face sheets, and featuring a controlled impact damage on one side. Data were collected on the damaged side of the panel using a network of piezo-electric sensors mounted on the face sheet. Two (potentially complementary) algorithms were implemented for detecting and localizing the fault from ultrasound data collected before and after damage. The algorithms use variants of the standard least-squares approach for estimating damage location, and are distinguished mainly by their reliance on qualitative versus quantitative physics models of acoustic wave propagation in the panel. Successful detection and localization of a sub-inch fault is demonstrated.