MICROMECHANICAL APPROACH TO THE TENSILE-STRENGTH OF UNIDIRECTIONAL COMPOSITES .2. STRENGTH OF UNIDIRECTIONAL COMPOSITES

This paper deals with the strength of dry bundles and unidirectional c omposites. Tensile tests of dry bundles and unidirectional composites of carbon fibers and alumina fibers are carried out. The strength of a dry bundle is compared with Coleman's theory and it is shown that the strength of a dry bundle can be well predicted by Coleman's theory. A s for a unidirectional composite, test data are compared with the Rose n model, the Zweben model, and the modified Zweben model. It has been confirmed that the Rosen model overestimates the strength whereas the Zweben model underestimates it. A modified Zweben model can represent the actual failure pattern, although some subjects are left for future investigation.