Study on the damages detection of 3 dimensional and 6 directional braided composites using FBG sensor

In this paper, the method of damage detection of three-dimensional and six-directional (3Dim 6Dir) braided composites by embedding FBG (Fiber Bragg Grating) sensors is studied. Firstly, the FBG sensors are embedded into 3Dim braided composites preforms along the fifth and sixth directions, and the 3Dim 6Dir braided composites with embedded FBG sensors are fabricated. Then, different kinds of damages are made on the composite materials. The signals of FBG sensors from the damaged composites are collected. By analyzing the signals of FBG sensors, it is found that different damages and different damage positions at the 3Dim 6Dir braided composites will make the wavelength of FBG sensor signals at different positions have unusual changes. This indicates that it is feasible to detect the damages of 3 Dim braided composites by using FBG sensors.