用于板壳应变检测的新型FBG传感器

New FBG Sensor for Board and Shell Strain Detection

在板壳材料实际装配过程中,由于预应力和尺寸位置偏差等因素的存在会产生装配变形,研究变形和应变分布最常用的方法是利用光纤光栅传感器阵列对其进行检测。目前表面粘贴式光纤光栅(FBG)传感器的封装体积较大,很难与工件达到完全贴合,检测精度低,难以实现大曲率跨度结构的变形检测。根据光纤光栅传感理论,研究并设计了适用于变曲率板壳结构的不锈钢箔片封装FBG传感器,使得该传感器能够与工件实现最大程度的贴合。同时利用悬臂梁加载试验对其应变灵敏度系数进行标定,采用ANSYS有限元软件和试验结果进行分析对比。结果表明,新型封装传感器提高了应力测量灵敏度且适应曲率为0.005~0.0075的板壳结构变形检测。

In the actual assembly process,assembly deformation occurs due to factors such as prestress and dimensional position deviation.The most common method to study the above deformation and strain distribution is using fiber grating with sensor array to detect it.However,the surface-attached Fiber Bragg Grating (FBG) sensor has a large package size and is difficult to fully conform to the workpiece.The monitoring accuracy is not very high,and it is difficult to realize the deformation detection of the large curvature span structure. Based on the fiber Bragg grating sensing theory,a stainless steel foil package FBG sensor suitable for variable curvature plate-shell structure is studied and designed,which enables the sensor to achieve maximum fit with the workpiece.At the same time,the strain sensitivity coefficient of the cantilever beam is calibrated by the cantilever beam loading experiment,and the strain sensitivity coefficient of the sensor is obtained.The experimental results are analyzed and compared with ANSYS finite element software.The experimental results show that the new packaged sensor has improved the sensitivity of stress measurement and is suitable for deformation detection of plate and shell structures with a curvature range of 0.005-0.0075.