THE EFFECT OF GEOMETRY ON THE PROPERTIES OF A DENSE ALUMINA-CARBON EPOXY LAMINATE/

This is a study of the effects of geometry on the properties of a lami nate made of dense, thin alumina plates alternating with carbon/epoxy (C/E) prepreg. An advantage of this system is the elimination of the l arge flaws occurring in fiber-reinforced ceramic matrix composites whi ch are responsible for the low stresses at first matrix cracking. Prev ious studies have been restricted to small specimens of simple geometr y. In this study attention has been directed to the influences of size , the introduction of notches and a geometry in which a large specimen is formed from a mosaic of small elements. The loss of stiffness with increase of the applied strain is compared to the predictions of a si mple one-dimensional, elastic-plastic shear lag theory. Although this model does not account for the branching phenomena observed in experim ent, there is good agreement with experiment, suggesting that branchin g has only a second order influence on mechanical properties.