Abstract:

The spectral finite element method (SFEM) is developed to model the surface-bonded piezoelectric wafer and beam structure.The Timoshenko beam theory,the Euler-Bernoulli beam theory and linear piezoelectricity are used to model the base beam and electric-mechanical behavior of the piezoelectric wafer respectively.The governing equations are obtained in the time domain by using Hamiltons principle,and then the Spectral finite element model are formulated via the fast Fourier transform.The SFEM is used to analyze the frequency response function,admittance characteristics and the influence of damage.The high accuracy of the present SFEM is verified by a comparison with the finite element method (FEM) results.The numerical model and its calculation results provide analysis basis for damage detection and assessment of the practical detection signal.

Key words: spectral finite element method SFEM;damage detection;electric mechanical admittance