Quantitative assessment of damage evolution of carbon fiber‐reinforced polymer laminates embedded with different nanoparticles using acoustic emission

Abstract Nanoparticles can be used to optimize the interface structure and improve the mechanical properties of fiber‐reinforced composites. Herein, the damage evolution of carbon fiber‐reinforced composites embedded with different nanoparticles has been investigated using acoustic emission (AE) technology. Principal component analysis is used to reduce the dimension of AE parameters. Combining fuzzy C‐means (FCM) clustering with hierarchical clustering can improve the clustering quality, which is helpful to apply FCM results to the quantitative evaluation of damage. For multiwalled carbon nanotubes, graphene, and cellulose nanofibres, the cumulative AE energy of matrix cracking increases by 39.29%, 51.12%, and 53.69%, respectively, that of fiber/matrix debonding increases by 13.5%, 118.5% and 56.58%, and that of fiber breakage decreases by 97.9%, 94.32%, and 87.6%, respectively. The addition of nanoparticles helps to improve the stiffness and toughness of epoxy resin, and restricts crack propagation, thus enhancing the interfacial properties. AE technology can successfully help quantitatively evaluate the damage behavior and the mechanism of different multiscale reinforced composites. AE characteristic responses within the composites are consistent with scanning electron microscopy results.