Understanding the damage mechanisms in 3D layer-to-layer woven composites from thermal and acoustic measurements

This article deals with an interlock woven composite and aims at providing a better understanding of the dissipative mechanisms activated under cyclic loadings and describing the damage scenario characteristic of heat build-up experiments. Since the ultimate objective of heat build-up experiment analyses is usually fatigue life predictions that are based on constitutive modelling, the correct interpretation of experimental results is essential. Three different loading protocols are proposed. The instrumentation of these experiments includes infrared thermometry and acoustic emission monitoring. The results show that the coupling of these two techniques provides useful information in order to identify the most important dissipation sources: viscoelasticity, damage and friction. Furthermore, by analysing different loading sequences, it is possible to elaborate the dissipation evolution scenario as well as the damage evolution scenario occurring during heat build-up experiments.