Structural Damage Detection Based on Frequency Response Function with Piezoelectric Transducer Excited by Alternative Signals

Piezoelectric transducers are widely used in structural health monitoring (SHM) systems due to their ability to convert mechanical energy into electrical energy and vice versa, establishing an electromechanical coupling with monitored structures. In this research, the technique used is based on the analysis of the frequency response function (FRF), with the objective of evaluating and comparing the efficiency of different excitation signals (chirp, burst, sinusoidal, impulse and white noise) in the detection of structural damage. The tests were carried out on aluminum and carbon fiber-reinforced plastic (CFRP) structures, where structural damage was induced by adding mass. In addition to the evaluation of the different types of signals, the effects of amplitude and frequency range were also analyzed, comparing them to the root mean square deviation (RMSD) and correlation coefficient deviation metric (CCDM) damage indices. The results indicate that the chirp and sinusoidal signals provided greater sensitivity in the detection of damage, standing out as the most efficient in both aluminum and CFRP structures.