Health Monitoring of Metallic Structures with Electromechanical Impedance and Piezoelectric Sensors

Abstract

In order to monitor the health condition of structures in a more sensitive and accurate way, a novel and universal methodology called direct coupling mechanical impedance (DCMI) for characteristic signatures extraction is presented in this paper. This methodology is used to obtain DCMI signatures from measured raw signatures (RSs) with the surface-bonded piezoelectric sensors (PZT), which is developed from a pertinent electromechanical impedance (EMI) theoretical model for surface-bonded circular PZT. The proposed DCMI methodology has the advantages of simple calculation and magnifying the signatures when compared with the existing methods. Combining the extracted DCMI signatures with the root mean square deviation (RMSD) index is able to quantify the correlation between the health condition and the signatures variation more effectively. To verify the effectiveness of proposed DCMI methodology, experiments are conducted on aluminum plates and a part of fuselage in detail. The experimental results sufficiently demonstrate that the presented universal DCMI methodology possesses better sensitivity than the raw signatures when utilized for evaluating the health condition of metallic structures, including those made of metal-matrix nanomaterials.

Electrical admittance of a circular piezoelectric transducer and chargeless deformation effect

“…As can be seen in the above equation, the effect of the installed sensor, Z a,eff , is excluded. This type of exclusion is also reported in [15,16,23,24].…”

“…The electrical admittance of the CPT can then be calculated by dividing the electric current by the electric potential which is equal to 1 V as mentioned earlier. Using equation (23), the indirect effective mechanical admittance of the host structure is eventually calculated, as illustrated in the schematic in figure 4. In this sub-section, the effective mechanical admittance is called indirect because the electrical admittance of the CPT is calculated at first and then the effective mechanical admittance of the host is indirectly retrieved using equation (23).…”

Pitting corrosion prediction based on electromechanical impedance and convolutional neural networks

“…At the same time, some scholars conducted corrosion monitoring based on EMI technology. [26][27][28][29][30][31] Park S K and Park S 32 combined the PZT patch, a miniaturized impedance-measuring chip, a microprocessor, and the radio frequency (RF) telemetry to develop a wireless corrosion monitoring device for metallic materials. Through the study of the accelerated corrosion process of aluminum alloy beams, it was verified that this method could achieve quantitative analysis of corrosion to a certain extent.…”