Research on damage identification method of aircraft panel structure based on fluctuation-based symbolic dynamics entropy

The panel structure is the main load-bearing component of core structures such as the aircraft fuselage and wing. In addition, as an important part of the aerodynamic shape, the smooth surface of the panel can significantly reduce flight resistance. However, when the panel is damaged, distortion of the aerodynamic shape increases flight resistance. Nonlinear vibrations, such as panel flutter, can occur, resulting in the propagation of structural fatigue cracks and even skin tearing. Therefore, it is essential for flight safety to improve the reliability of health monitoring of aircraft panel structure damage and build an intelligent health monitoring system. This paper focuses on the aluminum alloy panel structure and establishes a research framework for structural health monitoring based on Lamb waves. The fluctuation-based symbolic dynamics entropy is used as the damage feature extraction method. Numerical simulations demonstrate that this method has greater sensitivity, and computational efficiency than existing methods.