Numerical and experimental study on crack identification based on the piezoelectric ceramic lead zirconate titanate impedance technology

The structural health monitoring system with electromechanical impedance technique is studied numerically and experimentally in this article. A three-dimensional numerical model is developed to account for the electromechanical coupling effect between the structures and the piezoelectric ceramic lead zirconate titanate transducers, and it is verified by the experimental results. The proposed numerical model and experimental method are employed to analyze piezoelectric ceramic lead zirconate titanate impedance signature of the plate with transverse crack. The modal superposition is employed to determine the harmonic response analysis frequency range. The influences of the mesh density, the dielectric constants of piezoelectric ceramic lead zirconate titanates, and the positions of piezoelectric ceramic lead zirconate titanates are considered. The effects of the length of crack and the structural damping on the piezoelectric ceramic lead zirconate titanate impedance signatures are discussed. Based on this model, electromechanical impedance signatures can be used to identify cracks in a plate specimen. The value of the harmonic response peaks is seriously affected by the material parameters of piezoelectric ceramic lead zirconate titanate and the constant damping ratio. The resonant frequency is greatly influenced by the mesh sizes and the length of cracks.