Multiscale modeling and theoretical prediction for the thermal conductivity of porous plain-woven carbonized silica/phenolic composites

• Published in: Composite structures 2019-05, Vol.215, p.278-288
• Main Authors: Zhou, LiChuan, Sun, XiaoHao, Chen, MingWei, Zhu, YinBo, Wu, HengAn
• Format: Article
• Language: English
• Subjects: Effective thermal conductivity; Homogenization; Multiscale modeling; Plain-woven composites; Porous matrix
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2019.02.053

As a typical phenolic resin-based ablative material, silica/phenolic composites are extensively used in the aerospace industry. However, thermodynamic properties of carbonized plain-woven composites formed during ablation process are rarely studied. Toward this end, we propose a multiscale prediction model to investigate the effective thermal conductivity of porous plain-woven carbonized silica/phenolic composites by combining finite element analysis with existing two-phase composite models. A general approach is presented to compute the effective thermal conductivity with varying structural parameters. First, to consider effect of pores in phenolic resin matrix, the porous model is established to calculate the effective thermal conductivity of matrix with different porosities and pore morphologies. Then, heat transfer simulations are conducted on the multiscale model, including the yarn scale in the axial and transverse directions and the woven composite scale in the in-plane and out-of-plane directions. Empirical formulas for effective thermal conductivity are obtained, which comprehensively considers the factors of matrix porosity, fiber volume fraction, and temperature.