外贴啁啾光栅监测带双缺口复合材料静态拉伸损伤

啁啾光栅对沿其纵向的非均匀应变分布十分敏感，这种特性会反映在啁啾光栅的反射光谱图中。提出了一种利用外贴啁啾光栅监测带双缺口碳纤维复合材料损伤的新技术。实验结果表明，复合材料结构静态拉伸应变为4500 με与8500 με时，啁啾光栅反射光谱变化明显，这与复合材料应力应变关系曲线在应变8000 με时产生突变完全吻合，同时光栅反射光谱光强突变点位置与光栅几何位置完全一致，可实现对复合材料缺口位置损伤的定位及扩展监测。

Damage Monitoring of the Double-Notched Carbon Fiber Reinforced Polymers with Surface Bonded Chirped Fiber Bragg Grating Sensor

Chirped fiber Bragg grating (CFBG) sensors are sensitive to a non-uniform strain distribution along their longitudinal directions, and this effect is manifested in the power spectrum of the reflected light from the gage section. This paper describes a novel technique to monitor the damage of double-notched carbon fiber reinforced polymers (CFRP) lamination using the surface bonded CFBG sensor. The experimental results show that the reflection spectra of the CFBG sensor change distinctively within certain wavelength when the static strains of CFRP reach to 4500 με and 8500 με, which coincides with the strain change point of 8000 με in stress-strain relationship curve of CFRP laminates. The sudden change points of the reflected spectra have an one-to-one correspondence with the location of CFBG. So the proposed approach is useful for predicting the damage states and location of the notch in composite laminates.