Coefficients of nonlinear thermal expansion for fiber-reinforced composites

In the present study, a micromechanics model is proposed to predict the coefficients of nonlinear thermal expansion (CTEs) of fiber-reinforced composites. The influence of fiber aspect ratio on the CTEs is also investigated. It is noted that the parameters of fiber aspect ratio have a significant effect on both the longitudinal CTEs and transverse CTEs. The CTEs of composites are also very sensitive to the different fiber volume fractions. Moreover, the Young's modulus and Poisson's ratio of composites are taken into account in the present analysis. The theoretical derivations are applicable for the composites under mechanical or thermal environment conditions. The present model offers a direct prediction of CTEs and can account for the effects of fiber aspect ratio and volume fractions.