Calibration of a low-cost electromechanical impedance-based structural health monitoring device

Abstract

Steel structures undergo loads and stresses during service life, subject to structural damages such as fatigue, corrosion, cracks, and plastic deformations. Therefore, to detect damage, the dynamic responses of the structures are used, comparing two states: with and without damage. These dynamic responses are obtained from a signal representing the structure's electromechanical impedance. Thus, these impedance signatures must accurately represent the analyzed structure. By comparing the impedance signatures of the low-cost device used at UFG/UFCAT with the SySHM system developed by LMEst/UFU, it can be observed that the low-cost equipment requires calibration in its impedance measurements. This work proposes a method based on the Least-Squares approach to determine a mathematical model to convert the signals acquired by the low-cost device into signals suitable for analysis. In conclusion, it was feasible to demonstrate the utilization potential of the cost-effective device under impedance-based monitoring conditions.