提出了一种基于“钢管-质量块”弹性结构体的光纤光栅(FBG)加速度传感器,4个光纤光栅粘贴在质量块一侧的钢管表面应变的最大处,光栅分布在沿钢管圆周呈90°方位角的位置上,粘贴方向沿钢管的轴向。通过两两组合的光栅对的波长变化量的差值感测弹性结构体不同方向的振动加速度,实现二维测量及温度补偿。使用有限元软件进一步分析说明了传感器的测量原理及谐振频率。传感器性能参数测试结果表明,该传感器谐振频率为515Hz,与有限元分析结果基本吻合,灵敏度为0.88pm·m-1·s2,加速度测量范围为15~75m/s2;传感器二维振动测试结果良好,具备较好的抗干扰振动能力。
A novel fiber Bragg grating (FBG) accelerometer based on an elastic structure which consists of a stainless steel tube and a mass block is proposed. Four FBGs are fixed axially on the tube surface where produce the most large strain along the circumference of the tube with a 90° angle. Two-dimensional measurement and temperature compensation are realized through the change of two pairs of FBGs' wavelength shift caused by vibration. Finite element analysis is used to explain the two-dimensional measurement principle and the resonant frequency of the accelerometer further. Vibration test results demonstrate that the accelerometer possess of a resonant frequency of 515 Hz, a wide linear measurement range from 15 m/s2 to 75 m/s2 and a sensitivity of 0.88 pm.m-1 .s2, which is consistent with the finite element analysis results. The two-dimensional vibration test results show that the accelerometer has a good anti-interference ability.