Paul Murdy PhD Comp Exam presentation
- Wednesday, August 16, 2017 at 10:00am
- Roberts Hall, 301 - view map
Damage classification and remaining life prediction of GFRP composites with acoustic emission and guided ultrasonic waves
Wind turbines are rapidly increasing in size, so accurate on-line damage monitoring is becoming more and more important to their maintenance and safety. Acoustic emission (AE) has proven to be a very promising technique, which records stress waves caused by damage events occurring within large structures. Typically, wind turbine blades are predominantly constructed from glass fiber reinforced polymers (GFRPs) which exhibit more complex trends in damage progression than typical isotropic materials. Despite extensive research efforts, AE is by no means perfect for composite laminates. It still falls short in predicting remaining life of structures and differentiating between different types of damage. This research proposes a novel AE test method to be used in conjunction with conventional AE techniques to address these issues in both static and fatigue loading scenarios. The novel test method will involve sending ultrasonic impulses between the AE sensors, based on the concept that varying damage states within composite laminates will alter their acoustic responses. From the changes in these signals, damage states could be estimated to relate to the remaining life of laminates. Meso-scale finite element models will also be used in conjunction with the recorded AE data in an attempt to associate individual AE signals with specific types of damage occurring within the laminates.