Damage detection in laminated rubber bearings based on defect mode of periodic structure and electromechanical admittance

The detection of minor damages in laminated rubber bearings is of great significance, given their critical role in structural safety. The appropriate configuration of piezoelectric (PZT) transducers plays a crucial role in enabling effective structural damage detection through the PZT-based electromechanical admittance (EMA) method for complex structures. This study proposes a method for detecting damages in laminated rubber bearings through combined analysis of defect modes of periodic structures and EMA spectra. First, the periodic structure model of the laminated rubber bearing with periodically bonded PZT patches is established using spectral element method. Second, damage-induced defect modes within bandgaps are investigated through EMA spectra, revealing the correlation between defect mode frequencies, and both the location and severity rubber layer damage. Third, root mean square deviation is proposed to examine the influence of damage severity, location, and actuator location on bandgap defect modes. Numerical simulations demonstrate the effectiveness of the proposed method in accurately locating and quantifying damages in laminated rubber bearings.