DAMAGE CHARACTERISATION IN OPEN-HOLE COMPOSITES USING ACOUSTIC EMISSION AND FINITE ELEMENT, VALIDATED BY X-RAY CT

The development of digital twins for life cycle monitoring of high performance composites is becoming a realistic goal. The use of permanently integrated sensors to obtain structural health information is a promising method by which finite element models could be iteratively updated for remnant life predictions. In the present work, we use acoustic emission (AE) sensors to detect the stress waves generated in open hole composites when damage initiates and grows under quasi-static tensile loading. Damage characterisation is performed on experimental AE data and compared to a finite element (FE)-based damage modelling framework. The results from these techniques are then validated through the use of X-ray computed tomography (CT) scans, conducted on partially loaded specimens. AE monitoring and the FE model show promise in detecting the severity of damage when specimens are subjected to progressive tensile loading, although the FE-based model underpredicts the failure load and further work is required for damage classification using AE signals.