thermo-electro mechanical impedance based structural health monitoring: euler-bernoulli beam modeling

In recent years, impedance measurement method by piezoelectric (pzt) wafer active sensor (pwas) has been widely adopted for non-destructive evaluation (nde). in this method, the electrical impedance of a bonded pwas is used to detect a structural defect. the electro-mechanical coupling of pzt materials constructs the original principle of this method. accordingly, the electrical impedance of pwas can sense any change in the mechanical impedance of the structure. a thermal stress on a structure, which was generated by environmental temperature, could change the electrical impedance of pwas. the thermal stress which affects the output impedance of pwas is also developed. a temperature-dependent model, the temperature dependency of pwas, and structure material properties are investigated for a pwas bonded to an euler bernoulli clamped-clamped beam. the rayleigh-ritz and spectral element methods are studied and, then, verified by 3d finite element method (fem).