环境温度对PZT阻抗特征的影响

机电阻抗(EMI)法是目前结构健康监测(SHM)技术中较热门的研究领域之一。实际应用中，EMI法测得的阻抗信号受温度干扰，因而对损伤产生误判。首先从理论上分析了温度导致阻抗发生变化的原因，然后以 EMI法中典型的压电陶瓷(PZT-5H)型陶瓷传感器为研究对象，测试分析了温度对 PZT 电阻抗特征的影响规律。 研究发现，阻抗峰值的频移与温度呈线性关系，且温度对峰值频移的影响与频率相关。进一步结合频率偏移及幅值的变化规律，建立了机电阻抗(EMI)法结构健康监测的温度效应修正模型。研究结果为消减环境温度对 PZT 阻抗特征的影响奠定了基础。

Effect of Ambient Temperature on Impedance Characteristics of PZT

The electromechanical impedance (EMI) method is one of the hot research fields of structural health monitoring (SHM) technology. However, in practical applications, the impedance signal measured by EMI method will be disturbed by temperature, resulting in misjudgment of damage. Firstly, the reason for the change of impedance caused by temperature is analyzed theoretically. Then, taking the typical PZT-5H ceramic sensor in EMI method as the research object, the influence of temperature on the characteristics of PZT impedance is tested and analyzed. It is found that the frequency shift of impedance peak is linear with temperature, and the influence of temperature on the peak frequency shift is closely related to frequency. Further, combined with the variation law of frequency offset and amplitude, the temperature effect correction model of structural health monitoring based on the mechanical impedance method is established. The results lay a foundation for reducing the influence of ambient temperature on the impedance characteristics of PZT.