Portable Optical Module for Fatigue Damage Precursor Detection

Reliable and operationally simple methods that can be used in the field are needed for expeditious fatigue damage precursor detection. We have developed a strategy for constructing a laser-based sensor for creep or fatigue damage detection and monitoringin aerospace components. The sensor detects precursors to crack formation occurring as early as the first 10% of fatigue life and, therefore, can be used to identify accumulated fatigue damage prior to crack initiation. The method then detects and locatesthe presence of micro-cracks that occur later in the fatigue life and alerts the user of imminent failure. Phase I laboratory experimental tests established the proof-of-concept, including the prototyping of a compact, hand-held instrument. During Phase IIwe will further refine our work with modeling the instrument, designing its specific components, assembling it and establishing its performance envelope. Phase II will culminate in constructing and field-testing the prototype system.