Extended multiscale FE approach for steady-state heat conduction analysis of 3D braided composites

A new multiscale finite element (FE) calculation procedure is presented to predict the thermal conductive performance of 3D braided composites by a combined approach of the multiscale asymptotic expansion homogenization (MAEH) method and multiphase finite element (MPFE) approach. The analysis was performed based on a homogeneous macrostructure model and a heterogeneous microstructure representative unit cell model. The heat flux distribution, temperature distribution of 3D braided composites under different boundary conditions are basically predicted. It is found that the heat flux transmission is mainly along fiber orientation direction and the heat flux of the braiding yarns in the center region is much higher than that in the outer region. Effective coefficients of thermal conductivity (CTC) of 3D braided composites is predicted and compared with experiment data available in the literature to demonstrate the accuracy and reliability of the present multiscale FE approach. The procedure, which can be implemented into commercial finite element codes, is an efficient tool for the design and analysis of a heterogeneous material with anisotropic properties or complex geometries.