Influences of Electrical Boundary Conditions on Second-Harmonic Generation of Ultrasonic Guided Wave Propagation in a Piezoelectric Plate

The influences of electrical boundary conditions on second-harmonic generation (SHG) of ultrasonic guided wave propagation in a piezoelectric plate are analyzed. Based on the modal expansion analysis for waveguide excitation, an accurate description for the SHG effect of primary ultrasonic guided wave propagation in a piezoelectric plate has been presented within a second-order perturbation approximation. The formal solution of the double frequency guided waves, constituting the field of second harmonic, has been developed. The analytical results clearly reveal that the SHG effect of primary guided wave propagation is closely related to the electric boundary conditions of the piezoelectric plate. It is found that under different electrical boundary conditions there is an evident difference in the SHG effect of ultrasonic guided waves, and that the SHG effect is highly sensitive to the electrical boundary conditions.