光纤光栅传感器用于飞行试验应变测量的可行性研究

Feasibility study of fiber Bragg grating sensor for strain measurement in flight test

为推进光纤光栅(FBG)传感器在飞行试验应变测量中的应用,对其进行地面验证试验,并分析传感器封装结构、测试粘接工艺对应变测量的影响。FBG在飞行试验应用中具有体积小、质量轻的优势,但光纤易受损,需用不锈钢基片将光纤封装后使用AB胶与被测基体粘接。该文通过FBG与电阻应变计对比实验,验证其应变测量可行性,结果表明,FBG传感器响应趋势与电阻应变计一致,但封装后的FBG在胶结层存在较大应变损失;进一步建立应变传递模型进行仿真分析,定量计算测量误差,提出在满足飞行试验工艺可行性的前提下,胶结层厚度应尽量小,弹性模量应尽量大,即可有效提升FBG应变测量精度。

In order to promote the application of fiber Bragg grating(FBG)sensor in strain measurement of flight test field,ground verification tests were carried out,and the effects of the packaging structure and the bonding technology of the sensor were analyzed.FBG has the advantages of small size and light weight in flight test applications,but the optical fiber is easily damaged,so it is necessary to use a stainless steel substrate to encapsulate the optical fiber and then use AB glue to bond to the test substrate.In this paper,FBG and resistance strain gages are compared to verify the feasibility of strain measurement.The results show that the response trend of the FBG sensor is consistent with the resistance strain gauge,but there is a large strain loss in the bonding layer of the FBG after packaging.Further establish a strain transfer model for simulation analysis,and quantitatively calculate measurement error.It is proposed that under the premise of meeting the feasibility of flight test process,the thickness of the cement layer should be small enough and the elastic modulus should be large enough,which can effectively improve the accuracy of FBG strain measurement.