摘要
针对油气开采微地震监测高频检波器的要求,提出了一种基于对称铰链的光纤布拉格光栅高频加速度检波器结构,分析了该检波器的振动传感原理,利用仿真软件分析了该结构模型的谐振频率,同时对检波器的幅频特性、加速度响应灵敏度、横向抗干扰性能、冲击响应等性能进行了实验研究。实验结果表明:基于对称铰链结构的光纤布拉格光栅检波器谐振频率为1200 Hz,与利用软件仿真的谐振频率1191 Hz结果一致;在工作频率20~800 Hz,加速度灵敏度约为10.2 pm/g,线性系数为0.9998;交叉轴灵敏度约为主轴的5%;在谐振频率附近有很好的冲击响应特性。该检波器加工工艺简单、可靠性高、工作频带宽、灵敏度高、横向抗干扰性好,在石油开采等领域有很好的应用前景。
Aiming at the difficulty of existing optical sensors to meet the requirements of high-frequency vibration of micro-seismic monitoring in oil and gas production field,a high frequency FBG accelerometer based on symmetrical flexible hinges is proposed.The accelerometer is based on a compact structure consisting of a base,double hole hinge,a fiber Bragg grating and a mass block.There are threaded holes in the base to install the geophone on the vibration test table.Two small semi-circular rings are cut out on a cylindrical stainless steel material along the transverse symmetry using a line cutting technology.The upper and lower parts of the base and the mass block are engraved with 0.5 mm grooves along the axis.FBG is placed in the the upper part of the base and the mass block of the fiber trench.Both ends of FBG are glued to the mass block and base by epoxy adhesive.The FBG certain is applied to some prestress during packaging.When there is an external vibration signal,the base of the detector vibrates with the measured object.The mass block vibration around the center of the hinge relative to the base under the action of inertial force,driving FBG to stretch and compress,leading to a wavelength drift of FBG.The principle of vibration sensing is analyzed.The sensitivity and the resonant frequency formula of the accelerometer are given theoretically and the influence of structural parameter on the sensitivity and resonant frequency of the accelerometer is discussed.The modal analysis of the geophone is carried out using simulation software.The first order characteristic frequency of the structure is 1191 Hz,the vibration direction is x direction,and the second order characteristic frequency is 7039.4 Hz.The vibration direction of the second order characteristic frequency is y direction.As the two characteristic frequencies are very different,the geophone has good transverse anti-interference performance.To obtain the sensing performance of the detector,the amplitude-frequency response,sensitivity and lateral anti-in
作者
禹大宽
王向宇
高宏
刘钦朋
樊伟
乔学光
YU Dakuan;WANG Xiangyu;GAO Hong;LIU Qinpeng;FAN Wei;QIAO Xueguang(Shaanxi Key Laboratory of Optical Information Technology,School of Physical Science and Technology,Northwestern Polytechnical University,Xi′an 710129,China;Shaanxi Engineering Research Center of Oil and Gas Resource Optical Fiber Detection,School of Science,Xi′an Shiyou University,Xi′an 710065,China;School of Physics,Northwest University,Xi′an 710069,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2022年第10期164-172,共9页
Acta Photonica Sinica
基金
国家自然科学基金(Nos.61735014,61927812)
陕西省教育厅项目(Nos.18JS093,20JS122)。
关键词
光纤布拉格光栅
应变传感
加速度检波器
铰链
幅频响应
Fiber Bragg grating
Strain sensing
Accelerometer
Hinge
Amplitude-frequency response
