The application of the coupled field finite element (FE) analysis to evaluate the damage index of piezo sensor (PZT) bonded on to a concrete beam is investigated. The coupled-field FE analysis would interact with elastic, dynamic, and electrical fields simultaneously compared to ordinary FE analysis. Initially, the direct piezo electric effect is studied by applying a longitudinal force on the piezo electric sensor. Then a series of coupled field numerical studies are performed on concrete beams, for assessing damage under different extent and locations. The numerical model developed for the beam segments is utilized to study the effect of internal damage diagnoses using the surface-bonded PZT transducers and embedded PZT transducers. The results show that the PZT sensor affixed on the surfaces of beam are less sensitive than the embedded PZT transducer for diagnosing the internal damage of the beam. Further, variation of admittance with respect to material property of concrete cube is studied.

Keywords: Finite-element method, Coupled field analysis, Piezoelectric sensor, Harmonic analysis, Damage detection in concrete structure, Impedance based analysis.