A microscale integrated approach to measure and model fibre misalignment in fibre-reinforced composites

Computational micromechanics of fibre-reinforced polymers (FRPs) relies on the ability of the representative volume elements (RVEs) to take into account the different features that characterise the geometry of the material system under consideration. Fibre misalignment has been proven experimentally to have a significant effect on the mechanical properties at the macroscale, but is not currently taken into consideration in models at the individual fibre level, perhaps due to the difficulty in statistically characterising the fibre misalignment. In this work, an integrated approach is presented to measure and model fibre misalignments in FRPs. A computed tomography (CT) scan is used to identify the fibre geometry and statistically characterise the fibre misalignment angle distribution. Using a methodology recently developed by the authors, three-dimensional (3D) RVEs were generated by requiring their misalignment angle distribution to fit the empirical distribution. The methodology proposed provides a framework for the systematic numerical analysis of the influence of fibre misalignment on mechanical properties of FRPs.