裂纹智能梁的三维有限元动力谐响应分析

Three-dimensional Finite Element Harmonic Response of a Cracked Smart Beam

采用面向结构健康监测应用的压电阻抗模型,对粘贴有压电片的含裂纹梁结构采用三维有限元技术进行了高频压电阻抗谐响应分析.利用通用有限元软件ANSYS,建立由压电片-粘结层-含裂纹主体梁结构组成的耦合系统的三维有限元模型.并通过算例与振型叠加法和实验得到的结果进行了对比研究,验证了该模型的有效性和准确性.此外,还考察了有限元单元尺寸、振动模态、裂纹深度以及粘结层厚度对压电阻抗信号的影响.

An electro-mechanical impedance （EMI） model is presented in this paper for structural health monitoring purposes. The high-frequency EMI harmonic response of a cracked beam with surface bonded piezoelectric patches is investigated by employing the three-dimensional finite element method （FEM）. The three-dimensional FEM model of the coupled structural system consisting of PZT patches, bonding layer and cracked beam is established using the commercial software ANSYS. A comparison study with the mode superposition method and experimental results is adopted to validate the effectivity and accuracy of the proposed EMI model. Furthermore, the effects of finite element size, dynamic modes, crack depths and the thickness of bonding layer on EMI signatures in the high frequency range are also discussed.