Using Ultrasonic Waves to Determine Bond Quality Between Aluminum Plates

Structural health monitoring (SHM) addresses a pressing need of our aging infrastructure. The increasing costs of maintaining the aging infrastructure can be addressed through SHM systems that will decrease unscheduled maintenances while increasing safety and reliability. A more specific area of concern is in the aerospace industry. Most aircraft are made with a large amount of composites, which have unique damage types such as micro-cracking and delamination. These damages can cost an excess of money and lives if not detected early. This experiment was made to learn if non-contact SHM could be used to determine bond quality. This is important because layered composites are thin layers of different materials that are bonded together. In this experiment, aluminum plates were bonded together using adhesive film. Multiple pristine specimens were made as well as a damaged specimen, the damaged specimen had a piece of Teflon in the bonding. The plates were taken to an immersion tank to be scanned with ultrasonic waves. The scans were able to show variations in the bonds as well as the damage. This is good news, as further research can be done working toward an efficient and dependable SHM system for the aerospace industry