Structural health monitoring of a composite skin-stringer assembly using within-the-bond strategy of guided wave propagation. (15th January 2016)

• Record Type: Journal Article
• Authors: Sherafat, Mohammad H.; Guitel, Robin; Quaegebeur, Nicolas; Hubert, Pascal; Lessard, Larry; Masson, Patrice
• Is Part Of: Materials & design. Volume 90(2016)
• Page Start: 787
• Page End: 794
• Publication Date: 2016-01-15
• Subjects: Structural health monitoring (SHM) -- Composite joints -- Guided wave propagation -- Damage detection -- Skin-stringer assembly; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2015.11.018
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: The objective of this paper is to investigate the within-the-bond guided wave propagation in a composite skin-stringer joint. The structure of interest is composed of three carbon fibre reinforced polymer (CFRP) plates bonded together by adhesive film. This bonded joint is prone to disbond when submitted to extreme loads or fatigue. Therefore, two bonding conditions are investigated, namely undamaged and damaged (with disbond). The artificial disbond is introduced into the joint using a circular Teflon tape during manufacturing. Two co-localized slender rectangular piezoceramics are used to generate plane guided waves within-the-bondlines and non-contact measurement is performed using a 3-D laser Doppler vibrometer (LDV) to extract the required information for evaluation of the bonding conditions. The results include reflection, transmission and also scattering of the guided waves at the joint as a function of frequency, propagating mode and presence of artificial damage. It was found that the amplitude of the reflection, transmission coefficients and directivity patterns of scattered waves are affected by the presence of damage, such that Structural Health Monitoring (SHM) design guidelines can be derived for efficient damage detection in the composite assemblies using a within-the-bond inspection strategy. Graphical abstract: Highlights: In a pitch-and-catch configuration, the A0 mode is highly sensitive to the damage for frequencies below 350 kHz. An increase of 10% of the transmission is observed for the A0 mode in the damaged case. In a pulse-echo configuration, the S0 mode around 200 kHz could be used for monitoring an echo induced by a disbond. For damage imaging based on the scattering of the wave at the disbond, S0 mode appears as the best candidate below 350 kHz. An increase of 60% of the scattered field of the S0 mode is observed in the presence of a disbond.