当光纤光栅传感器埋设在结构中或粘贴于结构表面后,由于中间层的存在使结构的真实应变和光纤光栅传感器所测得的应变之间存在一个传递系数。在已有的应变传递理论的基础上,经过分析得出影响光纤光栅传感器应变传递的主要因素,它们是光纤光栅传感器的长度、中间层的厚度、弹性模量和泊松比。结果表明,光纤光栅传感器平均应变传递随着传感器长度的增加而升高,随着中间层厚度的增大而降低,随着中间层的弹性模量的增加而增大;中间层的泊松比对平均应变传递率的影响很小,在设计中可以忽略。
Optic fiber Bragg grating sensor requires a strain transfer coefficient when it is embedded in or adhered to the structure due to an interlayer between structure and sensor. The important factors that affect the strain transferring are deduced on the basis of existent theory in this paper, which include the length of the sensor, the thickness, Young's modulus and Poisson's ratio of the interlayer. The relationship between the average strain transfer rate and the parameters is discussed. The results show that the average strain transfer rate increases with sensor length, decreases with the thickening of the interlayer, rises with the increase of the interlayer Young's modulus. The influence of the interlayer Poisson ratio on the average strain transfer rate is very small and it can be neglected when choosing the interlayer parameters.