scale aircraft fatigue tests carried out in China. 3. Validation study on ICM system under operational environment From various levels tests mentioned above, it can verify that ICM system can detect damage in the aircraft structure. Furthermore, ICM product have excellent electromagnetic compatibility and environmental adaptability, which were tested by various harsh environmental loading experiments such as high/low temperature extremes, thermal shock, high humidity, fluid susceptibility, altitude/pressure etc. Hence, it is believed that that ICM system is reliable, robust, immune to radio frequency and electromagnetic interferences, easily networked to on-board preprocessing, capable of withstanding environmental conditions and low power which make it easier to obtain approve for installation of ICM hardware on aircraft structure in service. In order to put ICM into the oncoming real application, a study was carried to validate durability, reliability, longevity and crack detecting capability of the ICM system under actual flight condition and improve various properties accordingly. 3.1. Installation of ICM hardware One of overhauling fighter aircrafts was selected as the subject for the study.Total 78 sensors monitoring 42 fatigue critical sites distributed in different locations of the aircraft including wing, fuselage, horizontal tail and landing gear which were distributed symmetrically along the yaw axes of the aircraft, as listed in Table 1. All those sites determined by full-scale fatigue test and finite element analysis were impossible to access by conventional NDT methods. Each side of sensors was connected by 6 sub-interrogators which were connected by one main-interrogator. Actually two independent ICM systems are responsible for two sides of the aircraft. Figure 10 shows the distribution of ICM hardware in a whole aircraft. Table 1 Sensors and locations in different structural components (one side of aircraft) Figure 10 Laying-out of ICM hardware
RkJQdWJsaXNoZXIy MjM0NDE=