Portable Non-contact Ultrasound Detection for Aircraft Fatigue Damage

Due to the aging and fatigue loading, the microstructures of flight-critical aircraft components can develop fatigue cracks. If undetected, these cracks will expand and produce the eventual catastrophic failure of the component. High performance materials, for example titanium alloys, are particularly susceptible to fatigue cracks. The problem is complicated when the sensitive area lies beneath other materials. Removal of these materials can be costly and time-consuming. A rapid and portable method of nondestructive evaluation is called for. Research Support Instruments proposes to develop a novel laser-based ultrasound system using Gas-coupled Laser Acoustic Detection, or GCLAD, for the non-destructive testing of aircraft components for fatigue cracks and other defects. Unlike other laser-based detection techniques, GCLAD operates independently of the optical properties of the sample surface. Instead, the probe laser intercepts the ultrasound wave after it has been transmitted to air. Thus it is equally effective on any surface. This advanced system offers hangar-to-hangar portability, low cost, easy operation, and easy maintenance.