ON THE EFFECTIVE MODULI OF ANISOTROPIC COMPOSITES WITH ALIGNED ELLIPSOIDAL INCLUSIONS

The effective elastic and shear moduli of a 3-D composite containing a ligned ellipsoidal inclusions are evaluated in this paper. The materia l considered is transversely isotropic due to the uniform dispersion o f inclusions in plane sections normal to their major axis. The method followed for the solution of the problem is based upon Eshelby's theor y. We evaluate the strain field around a single ellipsoidal inhomogene ity surrounded by the effective anisotropic medium. Considering the mu tual interaction of the neighbouring inclusions inside the matrix, we may evaluate the effective stiffness of composites with inclusions at dilute concentrations by using Mori-Tanaka's concept. The parameters i nvolved in the analysis are the aspect ratio of the inclusions, their volume fraction and the ratio of the elastic moduli of the constituent phases forming the composite. The results show that the anisotropy of the composite is rather affected by the hardness of the inclusions re latively to the matrix than by the aspect ratio of inclusions. On the other hand, the stiffness of the composite is rather greater in models with inclusions afa needle-shape form than in composites with spheroi dal inclusions.