基于三维有限元分析的压电阻抗模型及其应用

为了校核高频电阻抗分析的现有结构理论和验证，基于高频电阻抗信号的结构损伤监测方法的有效性，提出可应用结构健康监测的精确压电阻抗有限元模型.考虑压电片-黏结层-主体结构三者的耦合作用和黏结层的影响，通过三维有限元谐响应分析方法，利用通用有限元软件ANSYS，建立由压电片-黏结层-主体结构组成的耦合系统的三维有限元模型，并进行了数值模拟和相应的实际模型试验.计算及研究结果表明：采用三维精细压电有限元模型，可精确地预测到电导纳谱中的共振模态，得到的结果与实验结果吻合，且能有效地校核高频电阻抗分析的现有结构理论；采用压电阻抗法能够很好地识别结构局部的细小损伤，通过合理布置压电片可以识别结构损伤的位置.

Three-dimensional finite element analysis based electromechanical impedance model and its application

An accurate electromechanical impedance(EMI) finite element model was established for structural health monitoring, in order to check the existing structure theories for high frequency impedance analysis and to verify the effectiveness of the damage detection method based on high frequency electric impedance signals. The coupling interaction among piezoelectric patches, adhesive layer, and main structure was considered and the effect of adhesive layers on EMI signals was further taken into account. A three dimensional finite element model was developed to simulate this coupled structural system using the software ANSYS and the correlative experimental study was conducted. Results showed that the harmonic analysis based on the three dimensional finite element model could predict the vibration modes of the structure at high frequency, which agreed well with the experimental results, and the existing structure theories for high frequency impedance analysis were effectively checked. Further study also showed that the EMI technique can feasibly detect small and local damages in structures. In addition, the location of structural damage can be determined through reasonable distribution of piezoelectric-ceramic patches.