Analysis of damage mechanisms in a centrally notched glass-fiber/epoxy plate
Résumé
The object of this study is to investigate the damage and failure mechanisms in a glass-fiber/epoxy composite under monotonic tensile loading. The testing was carried out on unidirectional specimens with and without a circular hole. The damage initiation and failure mechanisms were studied by means of scanning electron microscopy and acoustic emission monitoring. In addition, for specimens with a circular hole, a novel strain-gage instrumentation method is suggested. These different techniques permitted the determination of the damage parameters e, v, D, F, which characterize qualitatively and quantitatively the initiation and evolution of damage. It was found that the amplitude distribution of acoustic emissions is a very efficient tool for identifying damage mechanisms such as microcracking in the resin, fracture and friction of the interface between fiber and matrix, and fiber pull-out.