In-Flight Seeded-Fault Monitoring of URV Components Under Operating and Extreme Maneuvering Conditions

The validation of damage detection methods for condition-based maintenance (CBM) is ideally proven through flighttesting. Using manned aircraft to verify the damage detection system may not be viable due to airworthiness requirements, which must ensure the safety of the flight crew. Alternatively, using an Unmanned Rotorcraft Vehicle (URV) as a testing platform provides a unique opportunity to monitor seeded cracks and their growth on critical aircraft components without risking the safety of the flight crew. Hence, the U.S. Army Research Laboratory (ARL) is collaborating with Acellent Technologies to advance the diagnostics capability of their sensor system to detect embedded flaws/damage on URVs during operating and extreme loading conditions. The specific technical objectives are: 1) measuring the sensitivity to damage growth under low and high strain rate maneuvers for metallic and composite components, and 2) measuring the response due to varying damage types at the specific flight regimes. As incremental damage is introduced either through extreme flight maneuvers or through additional damage actuations, the previous damage detection dataset is used as the baseline for the current damage detection analysis. Analysis of the signals indicated a structural change within the principal stress element from the damage. Future work consists of inducing the damage in-flight, which will assess Acellent's technology for crack initiation detection that may be employed for Army vehicles.