金属化粘接层对FBG应变传感性能的影响

Influence of metal bonding layer on strain sensing performance of FBG

根据光纤布拉格光栅(FBG)应变传递模型,仿真分析了粘接层弹性模量、长度、厚度和泊松比对FBG应变传递效率的影响。分析结果表明,金属化粘接层应变传递特性优于环氧胶粘接层;金属化粘接层越长,FBG应变灵敏度越高,稳定性越好;厚度越小,应变传递效率越高,泊松比的影响可以忽略。采用新研制的FBG金属化连接技术将FBG封装到钢丝上,对不同粘接长度、粘接材料的FBG进行了拉力试验。实验结果表明,当Zn粘接层长为15mm、20mm时,FBG平均应变灵敏度为1.076pm/με、1.099pm/με,平均应变传递效率分别为0.948、0.962;金属化连接的FBG应变传递系数相比环氧树脂胶连接方式提高8.9%。理论与实验相一致。

Metal bonding layer seriously affects the strain transfer performance of fiber Bragg grating （FBO）. Based on the model of strain transfer of FBG-, the effects of the length, the thickness, Poissonls ratio, elasticity modulus of bonding layer on the strain transfer coefficient of FBO are analyzed by numerical simulation. The results show that the metal bonding layer has a larger advantage than the epoxy glue layer in strain transfer performance. The strain transfer coefficient increases with the length of metal bonding layer,decreases with the thickness of metal bonding layer and the influence of Poissonrs ratio can be ignored. The FBO is packaged to steel wire using the metal bonding technology. The tensile tests under different bonding lengths and elasticity moduluses are carried out. The results indicate that the strain transfer coefficients of FBGs are 0. 948,0. 962 and the average strain Sensitivities are 1.076 pro/ re, 1.099 pm/μe when the metal bonding layer is zinc, whose length is 15 ram, 20 mm, respectively. The strain transfer coefficient of the Ft packaged by metal bonding layer is enhanced by 8.9 - compared with the epoxy glue packaged one. The experiment result is general agreement with the analysis and pro- vides guidance for metal package of FBG.