Abstract:A three-layer spectral finite element model, consisting of piezoelectric wafer active sensor (PWAS), adhesive layer and base structure, is developed to study PWAS-induced Lamb wave propagation in structures. Based on different beam theories for different layers, governing equations and force boundary conditions are derived for the coupled PWAS-adhesive layer-base structure system, by which spectral finite element model is established. Compared with the conventional finite element method, the developed model is proved to obviously improve calculation efficiency and have high accuracy in modeling Lamb wave propagation. Output voltage versus exciting frequency, the length and thickness of PWAS and the thickness of adhesive layer is analyzed, which may provide some references for PWAS and Lamb wave-based active health monitoring technology.