INVESTIGATION OF DEBONDING PROCESSES IN PARTICLE-FILLED POLYMER MATERIALS BY ACOUSTIC-EMISSION .2. ACOUSTIC-EMISSION AMPLITUDE AND ENERGY-RELEASE BY DEBONDING

A theoretical description of the debonding process is presented by usi ng Griffith's criterion of rupture, that is applied to the balance of free energy during the debonding of a spherical filler particle from t he polymer matrix. Debonding processes in model composites prepared fr om epoxy and polyethylene matrix filled with glass beads of various si zes have been investigated by acoustic emission analysis. The amplitud e distribution for all AE events at the debonding stress was calculate d and fitted by a Weibull distribution function. By comparing the resu lts of debonding stress with the measured amplitudes, the influence of the different filler coatings on the energy balance of debonding can be discussed on the basis of the Griffith theory.