Inverse Micromechanical Models for Compressive Strength of Unidirectional Composites

Abstract

Compressive strength of composites is an important engineering requirement. Experimental determination of compressive strength of composites is very much time consuming and error prone. At present, there are some micromechanical models available in the literature to predict the compressive strength of unidirectional composites. But these models require fiber and resin mechanical properties as input. Resin mechanical properties can be obtained experimentally. But there are no standard test techniques for the evaluation of mechanical properties of fibers. In this study, an analytical method is presented for the evaluation of elastic properties of transversely isotropic fibers. Starting with experimentally obtained compressive strengths of typical unidirectional composites and inverse micromechanical models, elastic properties of the transversely isotropic fiber are obtained. This approach gives current elastic properties of the fibers, and not the virgin properties. Further, starting with the current fiber and resin elastic properties, compressive strength of unidirectional composite is determined using micromechanical models for different fiber volume fractions.