Interphase model for FE prediction of the effective thermal conductivity of the composites with imperfect interfaces

This paper addresses the Finite Element (FE) homogenization of the Effective Thermal Conductivities (ETCs) of the Composites with Imperfect Interfaces (CIIs). To model the imperfect interfaces between the matrix and inclusions in the composites, the thin interphases between the matrix and inclusions are introduced, which are combined with the FE homogenization method to predict the ETCs of the CIIs. The Representative Volume Elements (RVEs) containing the interphases are adopted to characterize the micro-structures of the CIIs and generated by the modified Random Sequential Absorption (RSA) algorithm. Compared with the micro-mechanical models, the proposed interphase model with the FE homogenization method is validated to be able to accurately predict the ETCs of the CIIs. The simulation results demonstrate that the ETCs of the CIIs are size-dependent, and the interphase thickness in the range of 50.0–100.0 nm has few impact on the ETCs of the composites. In addition, the ETCs of the CIIs show an asymptotic behavior so that a transition zone and two plateaus zones can be identified for the curves of the ETCs of the CIIs. This work provides a new and simple approach for predicting the ETCs of the CIIs.