热-结构耦合作用下压电式力传感器热应力分析  

Thermal Stress Analysis of Piezoelectric Force Sensors under Thermal-Structural Coupling

作　　者：周远琴 李映君[1] 李宏宇 王桂从[1] ZHOU Yuanqin;LI Yingjun;LI Hongyu;WANG Guicong(School of Mechanical Engineering,University of Jinan,Jinan 250022,China)

机构地区：[1]济南大学机械工程学院,济南250022

出　　处：《西安交通大学学报》2025年第1期194-205,共12页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51875250);山东省自然科学基金资助项目(ZR2023ME109);济南市“新高校20条”科研带头人工作室资助项目(202228116)。

摘　　要：针对极端环境下高温传感器的可靠性受限于热应力,导致传感器零漂和温漂甚至失效的问题,提出了一种基于热-结构耦合的高温压电式力传感器热应力计算方法及其有限元模型。基于平衡方程和热-弹性理论,建立了传感器热弹性力学物理方程,分析了封装材料和温度对压电式力传感器热应力的影响规律。通过分析高温环境下压电式力传感器的热应力分布,确定传感器应力集中位置。对传感器热应力进行溯源,得到封装材料和晶组材料的热膨胀系数不一致导致热失配应力产生。将随机振动功率谱密度转换为加速度时域信号,利用多物理场耦合方法,分析得到传感器的最大热应力为134.61 MPa,小于材料的屈服强度300 MPa,验证了传感器在高温、高压和随机振动综合环境下具有良好的可靠性。通过研究氧化铝和氧化锆绝缘层对传感器最大热应力的影响,研究结果表明,温度为420℃时氧化铝绝缘层传感器的最大热应力比无绝缘层传感器的最大热应力小9.18 MPa,比氧化锆绝缘层传感器最大热应力小79.31 MPa,该工作可为高温环境下减小传感器热应力措施提供一定的参考。To address the issue of limited sensor reliability in extreme environments due to thermal stress,leading to sensor zero drift,temperature drift and even failure,a thermal stress calculation method and finite element model for high-temperature piezoelectric force sensors based on thermal-structural coupling.Based on the equilibrium equation and the thermal-elastic theory,the physical equation of thermoelastic mechanics of the sensor is established,and the impact of packaging material and temperature on the thermal stress of the piezoelectric force sensor is analyzed.By examining the thermal stress distribution of the piezoelectric force sensor in high-temperature environments,the areas of stress concentration within the sensor are identified.Tracing back the thermal stress of the sensor reveals that thermal mismatch stress arises from the disparity in the thermal expansion coefficients between the packaging material and the crystalline material.The random vibration power spectral density is converted into an acceleration time-domain signal,and the sensor’s thermal stress is analyzed using a multi-physics coupling method,yielding a maximum stress of 134.61 MPa,which is below the material’s yield strength by 300 MPa,confirming the sensor’s reliability in high-temperature,high-pressure,and random vibration environments.An examination of the impact of alumina and zirconia insulation on the sensor’s maximum thermal stress shows that at 420℃,the maximum thermal stress of the alumina-insulated sensor is 9.18 MPa lower than that of the non-insulated sensor and 79.31 MPa lower than that of the zirconia-insulated sensor.The research provides insights for reducing thermal stress in sensors in high-temperature environments.

关 键 词：高温传感器 热应力 多物理场 压电 

分 类 号：TH82[机械工程—仪器科学与技术]