Theoretical prediction for thermal expansion coefficients of unidirectional fiber-reinforced composites with variable elliptical cross-sections

Abstract

A three-dimensional theoretical model is established to predict the coefficients of thermal expansion for unidirectional fiber-reinforced composites. Based on ellipse cross-sections to approach to the actual state of transversely isotropic fibers, this thermo-elastic mechanics analysis reveals the influence of fiber azimuth angular variation, which is superior to other known theoretical solutions. Taking different material systems and some other theoretical solutions into consideration, we could find the theoretical predictions are consistent with the results of the finite element method and existing experiments and the proposed model offers better agreements. Particularly, we focus on the overflow phenomenon of the transverse coefficient at low fiber volume fractions, contributing to developing fiber-reinforced composite designability. For adapting to irregular fiber shape, this article is innovative with the fiber shape factor concept as the main point of cross-section shape effect. POLYM. COMPOS., 40:187–201, 2019. © 2017 Society of Plastics Engineers.