Structure Health Monitoring Based on AE Method During Full Scale Aircraft Fatigue Test Under Flight Loading Conditions

During the full scale civil aircraft fatigue test under flight loading conditions, acoustic emission was used to monitor the health conditions of the key components, thus guaranteeing the success of the whole test by the early detection of fatigue cracks. With high background noise due to severe vibration and high sound wave attenuation of the complex components, the AE work, especially the signal acquiring and processing, were confronted with great difficulties and high challenges. This paper presents a fast AE signal processing method with the varying trend analysis of the AE characteristic parameters, combining the spatial filtering techniques with multi-parameter correlation analysis identifications. A case study was undertaken to monitor the initiation of a fatigue crack in the bolt hole located at the central wing and the right wing jointing area. The results showed that the proposed processing method for AE signal successfully realized the real-time monitoring of the initiation and growth of the fatigue crack in the bolt hole.