基于光频域反射技术,建立一种应变传递模型,推导了光纤应变传递关系,分析了分布式光纤应变测量结果的影响因素。通过等强度梁弯曲实验,分别从粘贴长度和涂覆层剪切模量等方面研究了光纤传感器的测量结果。研究结果表明,粘贴长度越长,应变传递率越高,当粘贴长度达到一定值时,光纤中间区域的应变传递率为1,两端的逐渐减小,涂覆层和胶粘剂的剪切模量越高,应变传递率越大。工程应用中应选用剪切模量高的涂覆层光纤及胶粘剂,粘贴长度应大于需测量区域的长度。

Based on the optical frequency domain reflection technology, we establish a strain transfer model, derive the strain transfer relationship of fiber, and analyze the influencing factors of the distributed fiber strain measurement results. Through the equal-strength beam bending experiment, we study the measurement results of the fiber-optic sensor from the aspects of the adhesion length and the shear modulus of the coating layer. The results show that the longer the adhension length, the higher the strain transfer rate. When the adhesion length reaches a certain level, the strain transfer rate in the middle of the optical fiber is 1, and those of the both ends are gradually reduced. The higher the shear modulus of the coating layer and the adhesive, the greater the strain transfer rate. Therefore, coating fibers and adhesives with high shear modulus should be used in engineering applications, and the adhesion length should be greater than the length of the area to be measured.