A numerical investigation of effective thermoelastic properties of interconnected alumina/Al composites using FFT and FE approaches

• Particulate materials are modelled using the Lubachevsky–Stillinger algorithm.
• Thermoelastic properties are estimated using numerical approaches.
• Comparisons are performed between FEM and FFT approaches.
• Results highlight some benefits and limits of the FFT approach.
• Comparisons are also performed with experimental measurements.

The present paper deals with a numerical investigation of effective thermoelastic properties of interconnected alumina/Al composites. This work uses a numerical approach initially introduced for investigating the thermal conductivity of particulate composites. In this paper, adaptations are carried out in order to evaluate both thermal and elastic coefficients using FFT and FE methods. In a first step, both methodologies are set up and validated for the context of particulate composites without interconnection. Effects related to both discretisation and number of particles are discussed, and a statistical volume element is finally determined. In a second step, the complex microstructure of interconnected alumina/Al is reproduced considering interconnection areas which are introduced and controlled using the cherry-pit model. Effective thermal conductivity and Young’s modulus are assessed and compared to third-order estimates and experimental measurements. Results show a good agreement between the numerical methods and the analytical formula. However, all predictions do not meet the experimental measurements, indicating the presence of flaws within the material.