Monitoring damage evolution with acoustic emission in two types of glass epoxy laminates

This study concerns the identification and monitoring by acoustic emission (AE) of the different damage mechanisms leading to the final rupture of glass/epoxy laminates. The series of specimens are subjected to static and fatigue loading in order to follow the progression of the various damage mechanisms over time and to identify the most critical ones leading to material failure. The specimens are made with two stacking sequences ([0/90]s and [90/0]s) using the vacuum infusion process. Several parameters such as the energy, the amplitude, the rise-time, the counts and the duration are used for the AE technique in order to identify the damage mechanisms evolutions to classify the collected events (AE). The damage mechanisms recorded in each stacking sequence are identified and characterized using a multi-parametric analysis. The damage accumulated in the test specimen is first of all transverse cracking, followed by interlaminar decohesion and finally fiber breakage leading to total composite failure.