Mean-field homogenization based approach to evaluate macroscopic coefficients of thermal expansion of composite materials

In this paper, a mean-field homogenization based approach implemented in the two steps sequentially is proposed to evaluate the macroscopic coefficients of thermal expansion (CTEs) of multi-phase composites. The adopted mean-field homogenization models are the quadratic interpolative M-T/D-I mean-field homogenization model in the first-step homogenization procedure and the simple interpolative Voigt/Reuss mean-field homogenization model in the second-step homogenization procedure, respectively. The proposed mean-field homogenization based approach is validated by comparing with the RVE based FE homogenization method. The simulation results indicate that with the increase of the inclusion volume fraction, the macroscopic CTEs of multi-phase composites generally decrease because that the inclusions possess the smaller CTEs than the matrices. However, in the case of multiphase composites with the planarly distributed inclusions, the through-thickness CTEs firstly increase with the increase of the inclusion volume fraction and then decrease with the increase of the inclusion volume fraction. The effect of the inclusion aspect ratio on the macroscopic CTEs of multi-phase composites "can be neglected, while the effect of the inclusion transversely isotropic material properties on the macroscopic CTEs of multi-phase composites must be considered. (C) 2016 Elsevier Ltd. All rights reserved.