Large-Area Structural Damage Nondestructive Evaluation

When testing composite structures, it is important to understand the response of the structure to the load. Of significance is the formation of damage and growth of that damage leading to ultimate failure. Understanding how a structure fails allows for optimal designs for improved safety and performance for the part during its lifecycle. Inspection methods are required to determine damage initiation and growth in advanced composite structures during loading. Past methods for in-situ inspection of composite structures during loading have involved acoustic emission, passive thermography, digital image correlation, and fiber optics techniques; however, each of these has critical limitations. The combination of thermal and acoustic emission (AE) nondestructive evaluation (NDE) techniques, by mapping the acoustic emission events onto the thermal imagery, provides a very sensitive measurement system for detecting damage formation and growth.