扭转梁式双光纤Bragg光栅加速度传感器的设计与有限元分析

The Design and Finite Element Analysis of Torsion Beam Dual FBG Acceleration Sensor

设计一种新型扭转梁式双光纤Bragg光栅加速度传感器,该传感器由扭转梁、扭转圆盘、质量块和光纤Bragg光栅组成,质量块受力带动扭转梁发生扭转变形,扭转圆盘将扭转梁的扭转变形放大到光纤光栅,通过检测光纤Bragg光栅中心波长的变化量即可检测出被测加速度信号。对已知传感器模型进行有限元分析,根据分析结果进行优化设计,确定最优方案。仿真结果显示:该传感器的固有频率为872.99Hz,灵敏度为16.118pm/(m/s^2)。该传感器克服了传统梁式光纤光栅传感器固有频率与灵敏度相互矛盾的现象,即在一定固有频率的基础上,可以通过增大扭转圆盘半径来放大传感器的灵敏度,因此该传感器可以实现对较高频率加速度信号的检测。

A new torsion beam dual-fiber Bragg grating acceleration sensor was designed and the torsion beam,torsion disk,mass block and fiber Bragg grating constitute it,in which,the mass block forced drives the torsion beam and results in a torsional deformation and the twisted disk maps the torsion deformation to the fiber grating.Through measuring the center wavelength variation of the fiber Bragg grating,the acceleration signal can be detected,including having the known sensor model analyzed with finite element method so as to determine an optimal scheme according to the analysis result.The simulation results show that,this sensor has a natural frequency of 872.99Hz and the sensitivity of 16.118pm/(m/s 2)and it overcomes the contradiction between the natural frequency and the sensitivity of the traditional beam fiber grating sensor,that is,on the basis of a certain natural frequency,the sensitivity of the sensor can be amplified by increasing the radius of the torsion disk so as to achieve high frequency of the acceleration signal detection.