A STATISTICAL MICROMECHANICAL MODEL OF ANISOTROPIC DAMAGE FOR SMC COMPOSITES

The objective of this paper is to predict the entire stress/strain cur ves and the loss of stiffness with damage for sheet-moulding-compound (SMC) composites. This is achieved by developing a statistical micro-m acro relationship with the help of the model of Mori and Tanaka. In th e case of an SMC composite with a 32% fiber volume fraction, debonding at the fiber/matrix interfaces is the predominant 'microdamage' mecha nism. In order to relate the microstructure, and its local perturbatio ns, to the macroscopic damaged behaviour, we introduce a statistical l ocal damage criterion and the concept of the equivalent damaged inclus ion in the micro-macro relationship of Mori and Tanaka. This paper sho ws the relationship between the statistical interface failure criterio n and the scattering observed on the macroscopic mechanical test resul ts. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.