Characterisation of Natural Flax Fibers Honeycomb: Compression Damage Analysis Using Acoustic Emission

The transport and construction industries are increasingly interested in natural fiber composites (NFCs) for the production of some of their structural elements. NFCs have significant advantages over synthetic fiber-based composites: lightweight, mechanical resistance, thermal and acoustic insulation. In addition, natural fibers are renewable and biodegradable, a significant advantage over synthetic and petrochemical-based fibers. In this study, honeycomb cores made from non-woven flax-epoxy composites are investigated. The experimental characterization focuses on their compressive response. Three different core densities are used: 100 g/m2, 150 g/m2 and 200 g/m2. In addition to the compressive behavior, honeycomb core damage was monitored using acoustic emission (AE). The K-means method was used to classify acoustic events and to identify damage mechanisms.