光纤光栅应变传感器测量应变误差分析

Error Analysis of Measured Strain of Fiber Bragg Grating Strain Sensor

光纤光栅应变传感器测量应变与实际应变并不相同,为了提高测量精度,需要研究测量应变与实际应变之间的关系。通过理论分析,得到了横向效应所引起的测量误差,针对复杂平面应变问题,修正了测量应变的计算公式,分析了安装角度、安装角度偏差等因素对测量精度的影响,得出:测量误差与安装角度成近似正弦变化,随着主应变比增大,应变测量误差逐渐减小。该理论为光纤光栅在实际中的应用提供了理论指导。

The strain measured by FBG(Fiber Bragg Grating)sensors is not equal to the true strain.To im-prove the measurement accuracy,the relationship between the measured strain and the real strain needs to be studied.Based on the theoretical analysis,the strain measurement error caused by the lateral effect is obtained.For the complex plane strain problem,the calculation formula of the measured strain was revised,and the effects of the installation angle,installation deviation angle on the measurement accuracy were analyzed.The analysis shows that the relative error of strain measurement is approximately sinusoidal to the installation angle.The relative error of strain measurement gradually decreases with the increase of the principal strain ratio.This theory has a high accuracy,and provides theoretical guidance for the application of fiber gratings.