Damage identification system of CFRP using fiber Bragg grating sensors

Carbon fiber reinforced plastics (CFRP) structure is very sensitive to impact damage, thus an early identification of structural damage is necessary to avoid major structural failures. In this paper, structural damage identification system by using fiber Bragg grating (FBG) sensors and damage identification algorithm for CFRP structure were investigated. Structural dynamic response signals, which contain the damage information, were generated by an active actuation method, and detected by FBG sensors. Damage characteristics were extracted by the Fourier transform and principal component analysis (PCA) methods. Then, based on the damage characteristic, one-class support vector machines (SVM) method was used to detect the damage, and multi-class C-support vector classification (C-SVC) methods were used to identify the damage area and evaluate the damage degree. At last, the damage identification system was established and verified on a CFRP plate. Within a 160 mm ∗ 160 mm ∗ 2 mm experiment area, the identification accuracy was more than 90%. This paper provided a reliable method for the CFRP structural damage identification.