Predictive Maintenance of Aircraft Primary Structures Based on Load Monitoring

The paper is focused to the development of a load monitoring system (LMS) capable to prevent eventual failures on primary structural elements based on the actual load history experienced by the aircraft during its life. The knowledge of the actual loads encountered by the aircraft and a numerical model able to predict failures allow to warn the aircraft operator that further inspections and eventual maintenance are required. The LMS is based on the data acquired by several sensors, some of them already present on any aircraft (to measure aircraft speed, altitude, load factor, etc.). Additional strain sensors are necessary to monitor the state of stress at certain locations that allow to estimate the actual load condition (e.g. shear, bending, torsion distribution on the aircraft wing box). The proposed LMS is tested with the ground static test of the winglet of a general aviation aircraft and will be applied in-flight to reconstruct the actual load conditions.