Research On Structural Health Monitoring Technology Based On PZT

As one of new smart materials, piezoceramic (PZT) has been used widely in many research fields. In this thesis, the application of PZT in structure health monitoring is studied and the PZT is used as both sensor and actuator. After the theoretical analysis, the experimental set-up is designed. Then the signals under normal status and loosened status are sampled and processed, the results demonstrate that the structure health status is judged successfully.The principle, characteristic and development of structure health monitoring technology based on PZT are presented in detail at the beginning. Then the basic theories of structure health monitoring using PZT are introduced, including the concepts and characteristics of smart material and structure, the application of PZT in smart structure and some basic theories of piezoelectric vibration. Afterwards the experiment of detecting bolts loosening is designed based on these theories, which includes designing experimental platform, choosing and sticking PZT, generating excitation signal, sampling data and preprocessing signal. From substantial experiments, the outputs of PZT under normal status and loosened status are measured and processed in frequency-domain using LabView. The results indicate that differences between two status can be seen easily. Lastly the method of judging structure health status using health index is discussed.The research results show that the proposed PZT approach can be used to achieve real-time and on-line structure health monitoring correctly.