The effect of aspect ratio of inclusions on the elastic properties of unidirectionally aligned composites

This paper examines the influence of aspect ratio α, from zero to infinity, on the effective elastic moduli of a transversely isotropic composite. The reinforcing inclusions, which could be flakes or short fibers, are assumed to be spheroidal and unidirectionally aligned. Of the five independent elastic constants, the longitudinal Young's modulus E 11 and in‐plane shear modulus μ 12 appear to increase with increasing aspect ratio, while the transverse Young's modulus E 22 , out‐plane shear modulus μ 23 , and plane‐strain bulk modulus K 23 , generally decrease. It is further noted that E 11 is more sensitive to α when α > 1 but the others are more so when α < 1. The present analysis was carried out by the combination of Eshelby's and Mori‐Tanaka's theories of inclusions.