双光纤-悬臂梁FBG加速度传感器研究

Research on Double Fiber-cantilever Beam FBG Acceleration Sensor

针对现有悬臂梁FBG加速度传感器光纤表面粘贴会造成FBG受力不均匀,并且无法在温度变化和振动等复杂的环境中工作的问题,提出一种双光纤-悬臂梁结构的FBG加速度传感器。理论分析了结构参数对传感器灵敏度和固有频率的影响,并采用ANSYS有限元分析软件进行了静应力和模态仿真分析,最后搭建了测试系统对传感器进行性能测试。结果表明,加速度传感器的固有频率为84.86 Hz,在15~60 Hz的低频段具有平坦的灵敏度响应,双光纤在增加传感器的灵敏度的同时有效消除了温度变化的影响,加速度灵敏度为156.70 pm/g,线性度为99.38%,刚性梁有效增加了结构的稳定性,在工作频段内的横向串扰为-26.97 dB。

The existing cantilever FBG acceleration sensor can be subjected to uneven force due to the optical fiber surface adhesion, and can not work in the complex environment of temperature change and vibration. In order to solve such problems, a dual fiber-cantilever structure FBG acceleration sensor is proposed. The influence of structural parameters on the sensitivity and natural frequency of the sensor was analyzed theoretically, and the static stress and modal simulation analysis was carried out by ANSYS finite element analysis software. Finally, a test system was built to test the performance of the sensor. The results show that the natural frequency of the acceleration sensor is 84.86 Hz, and it has a flat sensitivity response in the low frequency range of 15~60 Hz. The dual optical fiber can effectively eliminate the influence of temperature changes while increasing the sensitivity of the sensor, obtaining the acceleration sensitivity of 156.70 pm/g and the linearity of 99.38%. The rigid beam effectively increases the stability of the structure, and the lateral crosstalk within the working frequency band is-26.97 dB.