Spectral element modeling and analysis of the dynamics and guided waves in a smart beam with a surface-bonded PZT layer

To predict ultrasonic guided waves generated by a piezoelectric transducer (PZT) in a structure accurately, the dynamic coupling between the base structure and the surface-bonded PZT must be modeled accurately and analyzed in an efficient way. For so-called smart beams, which consist of a metallic base beam and a surface-bonded PZT layer, we propose a spectral element model that has the capability to accurately predict high frequency dynamic responses and guided waves. For the spectral element model, Timoshenko beam theory is applied to both the base beam and PZT layer, and Mindlin-Herrmann rod theory is adopted to account for the effects of lateral contraction in the thickness direction of the base beam. The high accuracy of the spectral element model is validated by comparing the results of the spectral element model with conventional finite element method (FEM) results and results from the commercial finite element analysis package ANSYS. The effects of PZT-induced axial-bending coupling and structural damping on the dynamics and guided waves are then investigated using numeral simulation.