An updated micromechanical model based on morphological characterization of carbon nanotube nanocomposites

Abstract

By leveraging on extensive morphological analysis of carbon nanotube nanocomposites, an update of the Eshelby-Mori-Tanaka method is proposed for a more accurate estimation of the nanocomposites effective elastic response. The experimental results are employed to overcome the main modeling limitations inherent in most common micromechanical theories, such as the perfect dispersion of the nanofiller and the uniformity of the nanofiller's aspect ratio within the nanocomposite. The actual variability of the CNTs aspect ratio and the CNTs degree of dispersion are experimentally measured and introduced in the proposed model by averaging the Eshelby tensor over the actual CNT lengths distribution and by accounting for the effective CNT volume fraction. The effects of the nanofiller morphology on the mechanical response of three different thermoplastic nanocomposites with low- and high-aspect ratio CNTs are explored, and monotonic tensile tests are performed to validate the predictions of the proposed model. A good agreement is found between the predicted nanocomposites elastic moduli and the experimental data.