DETERMINATION OF A TRIDIMENSIONAL FAILURE CRITERION AT THE FIBRE MATRIX INTERFACE OF AN ORGANIC-MATRIX/DISCONTINUOUS-REINFORCEMENT COMPOSITE/

The quality of the fibre/matrix interface is one of the most important factors for obtaining a good composite material. Many experimental pr ocedures have been developed to measure the fibre/matrix interface str ength, but these methods can only give a strength in terms of shear en ergy or shear stress limit. In this paper, we present two complementar y methods which try to obtain an interface debonding criterion in whic h the effect of the local shear stress is coupled with the local norma l stress on the interface. Experimental methods are defined and a micr omechanical calculation based on the stiffness prediction by the Mori and Tanaka approach is used. (C) 1996 Elsevier Science Limited