Damage Assessment in Composite Materials Using Low-Cost Air-Coupled Transducers

In this paper, results of damage assessment of composite panels based on non-contact guided wave generation and sensing are presented. Elastic waves are generated in a non-contact way using low-cost, low-frequency (40 kHz), resonant air-coupled transducers (ACTs). Elastic wave sensing is based on scanning laser vibrometry which allows to perform full non-contact damage assessment process. The authors investigated a glass fiber reinforced polymer (GFRP) panel with artificial damage simulated by Teflon inserts. Damage localization is performed using the wave irregularity mapping (WIM) algorithm. Moreover, the authors investigated the possibility of elastic wave generation with ACT at higher frequencies than it was designed to. The study showed that it is possible to generate elastic waves with a frequency of 55 kHz. The authors also studied the influence of single and multiple ACTs on damage localization results.