A Parametric Study of the Impact of Crack Parameters on EMI Response in RC Beams Using Correlation Analysis

The electromechanical impedance (EMI) methodology, utilizing lead zirconate titanate (PZT) smart material, stands as an effective non-destructive testing (NDT) approach for structural health monitoring (SHM). This paper explores the application of EMI to detect damage in reinforced concrete (RC) beams, a prevalent global structural type.

The technique involves using an LCR meter or impedance analyzer to electrically excite a surface-bonded PZT patch on the structure. The electro-mechanical (EM) admittance of the PZT patch is measured at defined intervals within a user-defined frequency range. The resulting conductance and susceptance components, when plotted against frequency, generate a unique signature for the structure. Any deviation from a benchmark signature obtained in an undamaged state signals structural damage. In this study, three surface-bonded PZT patches were employed to assess damage in RC beams. The alteration of EMI responses due to damage was quantified using root mean square deviation (RMSD). The research focuses on establishing a correlation between three critical crack parameters (width, length and horizontal distance from the PZT patch center) and RMSD values. Rigorous measurements and recordings of crack parameters were conducted and RMSD values were calculated at each load level. Statistical analysis, including correlation analysis, was applied to discern relationships between crack parameters and RMSD values.

The results provide valuable insights into the intricate interplay between PZT patches and crack parameters, aiding in the effective evaluation of structural damage in RC beams.