Finite-Element Analysis of an Electromechanical Impedance–Based Corrosion Sensor with Experimental Verification

Abstract

Corrosion-induced metal loss in critical structures is a widespread and urgent problem across multiple industries. In this paper, a novel corrosion sensor was proposed based on the theory of electromechanical impedance (EMI). The sensor was fabricated by bonding a lead-zirconate-titanate (PZT) patch onto the metal plate of the same cross-sectional area. The principle of the corrosion sensor is that corrosion-induced thickness loss of the metal plate leads to the change in the EMI of the sensor. Therefore, the corrosion amount can be determined from the impedance response of the PZT. EMI simulation of the sensor, together with modal analysis, was performed through finite-element analysis (FEA). Experimental verification studies were also conducted to validate the simulation results. Results showed that the peak frequency of the first transverse bending mode decreases with the loss of thickness, which can be used to determine the corrosion amount quantitatively. The proposed corrosion sensor has the advantages of low cost, quantitative determination of corrosion amount, and on-line and remote monitoring capability, which shows promising application potential.