基于柱式传感器表面光栅应变分析

Strain Analysis Based on FBG of Column Sensor Surface

柱式传感器常被用作压力传感系统,其表面粘贴的布拉格光栅(FBG)受到压力作用后感受到的应变与基底所产生的应变并不一致,导致系统的精度受限。本文首先建立起基底到FBG应变传递的理论模型,判断影响精度的因素,然后利用有限元仿真软件进行力学仿真,模拟粘接层弹性模和厚度对传感系统精度的影响,给出仿真曲线,验证理论建模正确性并为后续实验提供指导。实验结果表明,理论建模、有限元仿真和实验结果具有大致相同的趋势,经过反复实验,粘接层厚度在0.2 mm,弹性模量在10^(9) Pa左右,应变传递效率最高,传感系统的精度也提升到0.5%以内,大大提升了基底到光栅的应变传递效率。

Column sensors are often used as pressure sensing systems.The strain felt by the surface-bonded Bragg grating(FBG)under pressure is not consistent with the strain generated by the substrate,which results in the limited accuracy of the sensing system.First,the theoretical model of strain transfer from substrate to grating is first established to judge the factors affecting the accuracy.Then,the finite element analysis software is used to conduct mechanical simulation to simulate the influence of elastic modulus and thickness of the adhesive layer on the accuracy of the sensing system.The theoretical curve is given to verify the correctness of theoretical modeling and provide guidance for subsequent experiments.The results show that the theoretical modeling of finite element simulation and experimental results have roughly the same trend,after repeated experiments,the thickness of adhesive in 0.2 mm,modulus of elasticity at around 10^(9) Pa,the strain transfer efficiency is highest,the accuracy of the sensor system is promoted to 0.5%,greatly enhance the strain transmission efficiency of the system.