Comprehensive Structural Health Monitoring in Aircrafts with Smart Structure Using Built-in Dynamic Devices

近年来，碳纤维增强塑料（CFRP）复合材料已被应用于最新的民用飞机的主要结构部件。CFRP结构在循环疲劳荷载作用下，有可能发生层合层脱层、粘结层脱粘等损伤。本文研究了一种利用宽带超声传播系统检测结构损伤的健康监测技术。利用该系统，实验观察了兰姆波在结构构件中传播的宽带模态色散特性。由于完好区域的厚度与损伤区域的厚度有明显的差异，因此可以期望通过色散特性的变化来检测损伤。通过剥离损伤检测试验，研究了模态色散特性的变化与损伤之间的关系。

In recent years, carbon fiber reinforced plastic (CFRP) composites have been applied to the principle structural members in the latest civil aircraft. In CFRP structures, there is a possibility that some damages such as delaminations in the laminate, debondings in the adhesive layer and so on, occur under cyclic fatigue loadings. In this study, a structural health monitoring technique using a broadband ultrasonic wave propagation system to detect the damages was tested. By using this system, broadband modal dispersion characteristics of Lamb waves propagating in structural members were observed experimentally. Since the thickness of the intact area and that of the damaged area were clearly different, it was expected that the damages will be detected from the changes of the dispersion characteristics. Through the debonding damage detection tests, the relationship between the changes of the modal dispersion characteristics and the damages were investigated.