THE INFLUENCE OF AGGREGATED AND DISPERSED TEXTURES ON THE ELASTIC PROPERTIES OF DISCONTINUOUS-FIBER COMPOSITES

The elastic properties of short-fiber composites which exhibit fiber orientation distributions, are usually computed through an orientation averaging procedure conducted on the elastic properties of an equivalently loaded aligned-fiber composite. This type of 'aggregate' averaging scheme may be appropriate for materials of the sheet molding compound (SMC) type that exhibit the domain microstructure of an aggregate. However, this averaging scheme may not be applicable for 'dispersed' microstructures such as those observed in short-fiber injection-molded systems. This work presents a micromechanical model based on the concept of equivalent energy, which is capable of providing both approximate upper and lower bounds on the elastic properties of 'aggregated' and 'dispersed' systems of ellipsoidal inclusions.