石英挠性加速度计摆片纳米级应变原位测量  

In-situ nanometer-scale strain measurement for quartz flexible accelerometer pendulums

作　　者：王之昂 尹文浩 李慧[1] 周述军 赵乾[1] 孟永钢[1] 邵天敏[1] WANG Zhiang;YIN Wenhao;LI Hui;ZHOU Shujun;ZHAO Qian;MENG Yonggang;SHAO Tianmin(State Key Laboratory of Tribology in Advanced Equipment,Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;School of Mechanical and Electrical Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]清华大学机械工程系,高端装备界面科学与技术全国重点实验室,北京100084 [2]中国矿业大学(北京)机械与电气工程学院,北京100083

出　　处：《清华大学学报(自然科学版)》2025年第2期376-384,共9页Journal of Tsinghua University(Science and Technology)

基　　金：国家重点研发计划项目(2023YFB3811400);国家自然科学基金面上项目(52273296)。

摘　　要：石英摆片两侧金镀膜的应力及其对称性直接影响石英挠性加速度计的零位和精度,应力分布的建模仿真与原位测量表征显得尤为重要。该文建立了石英摆片的有限元模型,计算了石英摆片的基本模态,分析了石英摆片两侧应力差值对摆片变形及电容的影响规律,建立了摆片的应力-应变-位移-电容的变化关系。提出了一种基于电容法的非接触式应变测量方法,搭建了基于AD7747芯片的飞法级多通道测量装置,实现了20 nm级微小变形测量。该研究为石英摆片微小变形及其复杂环境条件下的原位检测提供了高精度有效测量方法。[Objective]The quartz pendulum is a critical sensitive component in quartz flexible accelerometers,and the stress distribution of the gold coating on both sides directly affects the deformation,zero position,and measurement accuracy of the pendulum.Enhancing the precision of the accelerometer requires an understanding of the influence of stress distribution on both sides of the pendulum on its zero position.This paper proposes a non-contact strain measurement method based on capacitance,introducing a high-precision,in-situ strain measurement technique.This method provides effective technical support for detecting small deformations of the quartz pendulum in complex environments.[Methods]This study begins by calculating the fundamental modes of the quartz pendulum using a finite element simulation model, which serves as the basisfor constructing and calibrating the measurement device. Thermal loads are then applied to both sides of the quartz pendulum'scoating in the simulation to induce stress, allowing the resulting deformation of the pendulum to be calculated. Therelationship between the stress difference on both sides of the pendulum and its deformation, as well as the correspondingcapacitance change, is subsequently derived. This process establishes the stress-strain-displacement-capacitance variationrelationship, providing theoretical guidance for the development of the quartz pendulum stress-strain measurement device.Afterward, a non-contact strain measurement method based on capacitance is proposed, and a multi-channel quartz pendulumstress-strain measurement system is developed utilizing the AD7747 chip. Through the adjustment of the displacementplatform to modify the pendulum position, a series of corresponding capacitance values are recorded. A linear relationship isthen fitted to calibrate the device. Finally, the system is validated, and its ability to accurately measure micro-deformations assmall as 20 nm is demonstrated. [Results] Using finite element simulation, this study successfully establishes

关 键 词：石英挠性加速度计 摆片变形测量 薄膜应力 

分 类 号：TH823[机械工程—仪器科学与技术]