Application of High-frequency EMI on Shell SHM with Diverse Radians

Exploring the application of electric-mechanical impedance (EMI) on structural health monitoring (SHM) of diverse systems or structures, especially the radian shell is very necessary to achieve the rapid online monitoring of structural damage. This paper studies the application of EMI on damage detection of shell structure with different radians. Using the piezoelectric equations of piezo-material lead zirconate titanate (PZT), the admittance values of aluminum shell before and after structural damage were got in a given frequency domain. Then by designing experiments based on Agilent 4294A instrument and analyzing the changes of admittance-frequency spectra before and after damage, it concluded the corresponding relationship between the sensitive detection frequency and the radian of the aluminum plate under given thickness; on the meantime, it is found that the damage index (DI) - root mean square deviation (RMSD) can be a judgment standard of damage by analyzing the data of special frequency band, which will has strong guiding significance for the selection of damage detection frequency and damage judging in arc structure hereafter.