Composite structures with built-in diagnostics

Composite materials are susceptible to damage which can be induced by service loads and accidental impact. Furthermore, internal damage in composites is difficult to detect and can have a detrimental effect on the residual strength of structures. Early detection of such damage is critical for maintaining the integrity of structures in use. Unfortunately, current composite structure inspection techniques are time consuming, labor intensive, and expensive, which significantly increases the overhead cost associated with the use of these structures. Current available techniques include coin tapping, X-ray, and ultrasound all of which require the structure to be taken out of service and often disassembled. This approach is uneconomical and sometimes impossible to implement