Abstract: A three-dimensional spectral element method (SEM) model including piezoelectric (PZT) structure coupling model for characterizing wave propagation in plate structures is developed. Characteristics of wave propagation in an isotropic aluminum alloy plate are therefore investigated. Dispersion relation of Lamb waves are studied by adding excitation force at the plate, so as to verify the simulated model. Characteristics of wave propagation under three excitation cases, i.e. one PZT disc, two PZT discs bonded on opposite sides of the plate with same and reverse excitation phases, are discussed. The damage in the plate structure is modeled by reducing the stiffness of the plate and wave interaction with damage is discussed. The conclusions and the proposed coupled PZT disc-structure model are validated by using experiments and the results demonstrate that the proposed three-dimensional SEM model can effectively and realistically simulate the excitation and capture of the responses of the structures, as well as wave propagation in structures, in comparison with two-dimensional SEM model.

Key words: Damage detection, Guided wave, Piezoelectric wafer, Spectral element method