A multi-scale model for the effective electro-mechanical properties of short fiber reinforced additively manufactured ceramic matrix composites containing carbon nanotubes

It is of paramount importance to accurately predict the mechanical properties of 3D-printed components for their usage and mechanical reliability. In this study, micromechanics models (mean-field and full-field) and the resistor network model are presented for predicting the effective elastic properties and electrical conductivity of 3D-printed material ceramic matrix composite. Due to the manufacturing process, two-scale (micro-scale and meso-scale) hierarchy is identified and the homogenization at each scale is performed with the appropriate model. The proposed approach is applied to short fiber reinforced additively manufactured alumina (Al2O3) ceramic matrix composite containing multi-walled carbon nanotubes (MWCNTs). The proposed models account for the reinforcements orientation distribution, reinforcements shape, porous reinforcements and multiple reinforcements. Parametric studies were carried out to show the sensitivity of the effective electro-mechanical properties of the 3D-printed composite filament to some geometric features which are related to processing. This work provides a methodology for predicting the effective electro-mechanical properties, derived from accurate micromechanics and resistor network models, for bridging lengths scales and use in macro-scale models to evaluate the electro-mechanical performance of composites part.