Explicit cross-link relations between effective elastic modulus and thermal conductivity for fiber composites

Explicit cross-link relations between effective elastic modulus and thermal conductivity for composites with different fiber orientation are derived with help of Mori–Tanaka micromechanical method. Numerical cross-link relations are also established by digital-image-based finite element method, and they compare favorably with the analytical cross-link relations especially for the composite with aligned fibers and planar randomly oriented fibers. Both analytical and numerical cross-link relations agree well with the experimental results available in the literature. For the composite with space randomly oriented fibers, the numerically obtained cross-link relations are insensitive to the fiber’s shape, and the analytical cross-link relations are weakly dependent on fiber’s shape. In sum, the sensitivity of cross-link relations to the fiber’s shape depends on the extent of anisotropic behavior of fiber composites. Such cross-link relations can be potentially applied for predicting the difficult-to-measure elastic modulus from the measured thermal conductivities.

► Based on Mori–Tanaka micromechanical method, cross-link relations of homogenized effective elastic and thermal properties of composites are derived. ► Geometric modeling of three dimensional microstructures is built for various types of composites in finite element simulation. ► The digital-image-based finite element method is used to numerically establish crosslink relations for fiber composites from the microscopic representative volume element (RVE) model. ► Both micromechanical homogenization results and numerical crosslink relations agree well with existing experimental measurements. ► The sensitivity of cross-link relations to the fiber’s shape depends on the extent of anisotropic behavior of composites. ► Such cross-link relations show great promise in predicting the difficult-to-measure elastic modulus from the available thermal conductivities.