Development of an SHM system of sandwich composite panels using guided elastic waves

B. Chapuis (1) , A. Kulakovskyi (2, 1) , N.-R. Bedreddine , O. d'Almeida (2)

1 DISC (CEA, LIST) - Département Imagerie et Simulation pour le Contrôle (CEA, LIST)
2 SAFRAN Group

Sandwich structures consisting of two face composite sheets and a honeycomb aluminium core are largely used in some aerospace components for their structural and light weight properties. However, they might be subjected to damages such as delaminations in the composite sheets or debondings between the face sheets and the core due to impacts or thermo-mechanical aging. We present here the latest studies performed through a collaborative project aiming at developing a guided elastic wave's based Structural Health Monitoring (SHM) system of such components. These waves can propagate in plate-like structures over large distances without significant attenuation. They allow to monitor wide zones with a limited number of sensors in order to detect, to locate and to characterize defects. In a first step of the study, the properties of the guided waves propagation in pristine sandwich panels are determined. Different modes are emitted thanks to piezoelectric patches of different diameters bonded at the surface of the plate. Modes characteristics (dispersion curves, attenuation, and anisotropy of the propagation) are determined thanks to laser Doppler velocimetry measurements. The same experimental setup is then used to highlight interaction of guided waves with calibrated defects of different diameters in sandwich plates (debondings between the face sheet and honeycomb core). These results allow to select the guided mode and its frequency which is the most sensitive to the defects. Measurements on a real large scale (3m x 3m) sandwich component are finally presented.

Mots clés: Debonding; Doppler effect; Elastic waves; Guided electromagnetic wave propagation; Honeycomb structures; Industrial applications; Piezoelectric materials; Plates (structural components); Sandwich structures; Aerospace components; Collaborative projects; Honeycomb sandwich structure; Laser Doppler Velocimetry; Piezoelectric patch; Plate-like structure; Sandwich composite panels; Structural health monitoring (SHM); Structural health monitoring

Domaines: Sciences de l'ingénieur [physics]

B. Chapuis, A. Kulakovskyi, N.-R. Bedreddine, O. d'Almeida. Development of an SHM system of sandwich composite panels using guided elastic waves. 8th European Workshop on Structural Health Monitoring, EWSHM 2016, Jul 2016, Bilbao, Spain. pp.1210-1219. ⟨cea-01843188⟩