A validation study for a SHM technology under operational environment

A newly invented Structure Health Monitoring (SHM) technology, named as Intelligent Coating Monitoring (ICM), was verified by various lab-scale experiments along with full-scale fatigue tests to investigate ICM capability for monitoring crack initiation and propagation in metal substances. In order to apply the technology to civil aircraft, the ICM system was validated under real service conditions. Firstly, ICM is briefly introduced, including the principle of the intelligent coating sensor, the make-up of the system and various lab-scale experiments as well as full-scale fatigue tests for verification and application. Then the installation of ICM system on an operational aircraft structure was given which includes the determination of critical locations that need monitoring, the selection of sensors corresponding to each monitoring point with certain geometry, the method of sensors splicing and main-/sub- interrogation units fixing and the connection of the above hardware through wires layed to form an ICM system. Finally, the operating situation and the effectiveness of the ICM system under operational environment were validated and summarized. It can be proven by the present investigation that ICM system installed on the aircraft structure can monitor cracks which might occur at any specified location, and most sensors along with other hardware can operate normally and effectively under actual condition.