Fiber Bragg grating (FBG) sensors based on the wavelength division multiplexing technology are ideally suitable for structural health monitoring. In many applications, it is desirable to form several arrays of optical fiber sensors to monitor the response of structures. In this paper, I constructed an improved FBG sensor system using a wavelength-swept fiber laser which exhibits the high power of output for several sensor arrays. The fiber cavity etalon was also fabricated for the calibration of the nonlinear output wavelength of the laser and for taking the information of wavelength domain in the signal processing. In order to monitor the structural strain real-timely, the signal-processing program was constructed for storing and visualizing data from FBG sensors. To estimate the overall performance of the constructed FBG sensor system, quasi-static and dynamic test were executed. The signal characteristics of FBG sensor were also examined in various bonding and embedding condition. The constructed FBG sensor system with the fiber cavity etalon and a reference FBG (WSFLWI) was applied for the strain measurement of the laminated composites. In the 4-point bending test, internal strain of laminated composite was successfully measured. And buckling behavior of composite laminated panel under axial compressive loading was monitored. Finally, the behavior of composite wing box embedded 24 FBG sensors was real-timely monitored in the bending test. Experiments showed that the constructed FBG sensor system and the real-time signal-processing program could successfully monitor the behavior of composite wing box. This improved FBG sensor system could be useful for the large structures that require a large number of sensor arrays.
