Research on wing impact damage detection based on a FBG smart interlayer and the BAS-LSSVM

The optical fiber self-diagnosis system is a crucial component of optical fiber smart structures, yet embedding optical fibers into composite materials poses numerous challenges. An most effective approach to resolving these issues is to integrate optical fiber sensors into a modular optical fiber smart interlayer that can be easily embedded into composite materials. This paper reports a study on wing impact damage detection based on smart fiber Bragg grating (FBG) interlayers and support vector machines. Axial tension, axial compression, and interlaminar tension tests demonstrate that the embedding of smart interlayers has a minimal impact on the strength properties of composite structures. Calibration test results indicate that the wavelength shift and strain of FBG sensors in intelligent interlayers exhibit a favorable linear relationship, and the interlayers can be embedded inside composite materials for stress and strain monitoring. Furthermore, wing impact damage tests show that the BAS-LSSVM is more suitable than the improved BP neural network for establishing an active, online, and real-time monitoring system for detecting structural damage.