Acoustic emission detection in CFRP cross-ply laminates by novel PS-FBG optical fiber ultrasonic sensor

摘要

Acoustic Emission (AE) detection as an effective nondestructive testing method has been widely used for improving the safety ratio of structural materials. Conventionally, AE signals are detected by lead-zirconate-titanate (PZT) sensor, which includes disadvantages of bulk size, and electromagnetic interferences (EMI). These disadvantages limit the application of PZT sensor in aircraft. Hence, some researchers have proposed fiber optical sensors (FOSs) as an alternative for solving these problems. Among many different optical methods, fiber Bragg grating (FBG), a punctiform robust sensor, is considered as a potential ultrasonic sensor. However, normal FBG cannot detect AE signals in composite materials because of the low sensitivity and narrow bandwidth.