提出了一种基于对称悬臂梁的小型化低频光纤布拉格光栅(FBG)加速度传感器。首先根据传感器结构的力学模型, 推导出传感器的灵敏度和固有频率表达式; 然后对传感器进行结构参数优化, 采用ANSYS Workbench对传感器进行静应力与模态分析; 最后根据分析结果制作传感器, 并实验研究了传感器的幅频响应、灵敏度特性、横向抗干扰能力和冲击响应。结果表明, 该传感器固有频率为72Hz, 灵敏度为681.7pm/g, 抗横向干扰度小于4.9%, 且体积仅为6.48cm3, 可用于50Hz以下的低频微弱振动信号的实时监测。

A miniaturized low-frequency FBG acceleration sensor based on symmetric cantilever beam was proposed. Firstly, the sensitivity and natural frequency expressions of the sensor were derived according to the mechanical model of the sensor structure. Then, the structural parameters of the sensor were optimized, and the static stress and modal analysis of the sensor were carried out by ANSYS Workbench. Finally, the sensor was made according to the analysis results, and its amplitude-frequency response, sensitivity characteristics, transverse anti-interference ability and impact response were studied through experiments. The experimental results show that the natural frequency of the sensor is 72Hz, the sensitivity is 681.7pm/g, the lateral interference resistance is less than 4.9%, and the volume is only 6.48cm3, which can be used for real-time monitoring of low frequency weak vibration signals below 50Hz.