In situ x-ray phase-contrast imaging of spark erosion of aeronautical fasteners

Imagerie par rayons X en contraste de phase de l'étincelage des fixations aéronautiques

Amélie Jarnac (1) , Rafael Sousa Martins (2) , Clément Zaepffel (2) , Fabien Tholin (2) , Patrice Blanchet (2) , Victor Désangles (2) , Laureen Guitard (3) , Adrien Stolidi (4) , Philippe Lalande (2)

1 DPHY, ONERA, Université Paris Saclay [Châtillon]
2 DPHY, ONERA, Université Paris Saclay [Palaiseau]
3 DOTA, ONERA, Université Paris Saclay [Palaiseau]
4 DISC (CEA, LIST) - Département Imagerie et Simulation pour le Contrôle (CEA, LIST)

In the context of lightning strike impacting aeronautical fasteners, we investigate the in situ behaviour of fasteners subject to a current level of a few kA by using high-speed Xray phase-contrast imaging in a synchrotron facility. It reveals that the fastener erosion occurs in two time scales. On a microsecond timescale, hot particles are ejected from cavity walls of the Carbon fibre reinforced polymer due to sparking/arcing phenomena, whereas on a sub-millisecond time scale, the fastener wall is vaporized due to the electrical energy deposited in the arc-fastener interface. The experimental observations have been used as input for an electro-thermal model of electric contact. The estimated vaporised depth is in good agreement with the measured one. The nature of the internal damages has been confirmed by using X-ray phase tomography.

Mots clés: fastener; spark erosion; X-ray

Mots clés: FIXATION; ETINCELAGE; CONTRASTE PHASE; TOMOGRAPHIE RAYON X

Domaines: Physique [physics]; Sciences de l'ingénieur [physics]

Amélie Jarnac, Rafael Sousa Martins, Clément Zaepffel, Fabien Tholin, Patrice Blanchet, et al.. In situ x-ray phase-contrast imaging of spark erosion of aeronautical fasteners. ICOLSE 2022 - International Conference On Lightning and Static Electricity, Sep 2022, Madrid, Spain. ⟨hal-03878296⟩