Lamb waves-based impact damage monitoring of a stiffened aircraft panel using piezoelectric transducers

The growth of the use of composite materials to replace traditional materials as primary structures remains limited by the significant inspection costs that are required to detect the appearance of internal defects. Indeed, many different damage processes can be observed in such kinds of heterogeneous media. The present article defines an in situ and nondestructive method for the impact damage monitoring of carbon/epoxy laminated composites. This structural health monitoring (SHM) method aims to improve the operational safety of the structure using integrated piezoelectric sensors. We describe the propagation of Lamb waves inside a stiffened aeronautical structure, and the definition of associated data processing systems. The detection of realistic defects thanks to the definition of a damaging parameter, based on the real time analysis of the ultrasonic signatures transmitted inside the structure is outlined.