ACOUSTIC EMISSION STUDIES IN GLASS FIBRE-POLYESTER COMPOSITES WITH RUBBER TOUGHENED MATRICES

Acoustic emission studies, using amplitude distribution analysis, have been carried out on glass fibre-polyester laminates, loaded in simple tension. The composite was tested in the unmodified state, and with a modifying rubber (a toughening agent) incorporated as a fine particulate dispersion in the resin matrix. Modification had little effect upon the orthodox mechanical properties of the laminate, but A. E. response was significantly altered. A detailed study was made of the evolution of AE event count in specified ranges of amplitude. This is interpreted as showing that modification with rubber particles causes resin matrix cracking to be deferred to higher strains. Preliminary micrographic evidence is presented in support of this contention.