Damage Identification Using Piezoelectric Impedance and Spectral Element Method

摘要

The basic idea of the impedance-based damage detection is that the electrical impedance of the piezoelectric transducer is directly related to the mechanical impedance of the host structure. Therefore, damage effect is reflected in the change of the piezoelectric impedance curves before and after damage occurrence. Previous studies in this area mainly focus on declaring damage occurrence. In this research, we develop a model-based identification method that can identify both the damage location and the severity of the damage. The model is built upon the spectral element method, which has high accuracy and numerical efficiency in the high frequency range. Using the difference between the measured and healthy impedance curves as input, an inverse identification procedure is developed to extract directly the property change of the elements. Extensive numerical and experimental studies are carried out to demonstrate the effectiveness of the proposed method.