Online health monitoring of marine structures using electromechanical impedance spectroscopy: A simulation approach

Electromechanical impedance (EMI) spectroscopy is categorized as an online and real-time structural health monitoring methods. Taking advantage of the simultaneous actuation/sensing characteristics of piezoelectric patches to excite the host structure in high-frequency ranges, as well as recording the dynamic signature, enables the EMI to identify incipient damages. Marine structures are often exposed to a variety of environmental damage, including corrosion which necessitates the use of structural health monitoring methods in their maintenance programs. This study aims to investigate the possibility of using EMI spectroscopy to detect damage in marine structures. In this regard, a multi-physics finite element simulation was used to model the vibration of a submerged beam and extract the EMI spectrum. To validate the model, the first 5 eigenfrequencies of transverse vibration in water are compared with the existing experimental results. Next, the variation of the EMI of a pristine submerged was investigated at three different depths. Finally, a corrosion defect was applied to the beam to study the potential of damage detection in the fluid medium. The monotonic behavior of the root mean square deviation damage index indicates its adequacy for damage identification in submerged structures.