Service induced damage in composite laminates: non destructive assessment, quantification and modeling

摘要

Acoustic emission is a powerful technique for identifying and monitoring the evolution of service induced degradation in structural components and localising damage. The present study is dedicated to the investigation of model composite systems in order to identify, locate and quantify service induced damage. These systems are cross ply translucent glass fibre reinforced composite materials. In cross ply composites, service induced primary damage is manifested in the form of matrix cracking of the off-axis layers. For the purposes of this study, the cross ply composite were subjected to step loading with the concurrent recording of the acoustic activity. At specific intervals of the loading process the propagation characteristics of ultrasonic waves were also recorded using the acoustic emission sensors in a pulser-receiver setup. The acoustic emission activity has been successfully correlated to damage accumulation of the cross ply laminates, while specific acoustic emission indices proved sensitive to the various modes that evolve during the loading.