Study Of Guided Wave Characteristics In Piezoelectric Semiconductor Plates And Cylindrical Shells

Piezoelectric semiconductors are of great value in aerospace,computing,energy,and microelectromechanical applications due to their unique piezoelectric and semiconductor coupling characteristics,such as integrated sensors for microelectromechanical applications and filters for 5G communications.The coupling characteristics of piezoelectric and semiconductor have a significant impact on the wave dynamics of piezoelectric semiconductor structures,and research on the wave dynamics of piezoelectric semiconductors can contribute to the development of applications and performance optimization of related devices.This paper therefore addresses the wave characteristics in the structure of piezoelectric semiconductor plates and cylindrical shells.The main studies are as follows:Firstly,the characteristics of guided waves in piezoelectric semiconductor and functionally graded piezoelectric semiconductor plates are investigated based on the linear phenomenological theory.The Legendre polynomial method(LPM)is applied to derive the governing differential equations at different electrical boundaries and then translate them into problems of solving matrix eigenvalues.The correctness of the method is verified by comparing the results with the existing literature.The effects of electrical boundary conditions,semiconductor properties,steady-state carrier concentration,and gradient fields on the dispersion and attenuation of guided wave are analyzed,and the distribution law of stresses in piezoelectric semiconductors as influenced by the steady-state carrier concentration is revealed.The results show that the electrical boundary conditions,steady-state carrier concentration and gradient field have significant effects on the phase velocity and attenuation of the guided wave,and the regulation of steady-state carrier concentration enables modulation of the guided wave characteristics.Second,the Analytic Legendre Polynomial Method(ALPM)is developed to overcome problems such as the low efficiency of the LPM.The characteristics of circumferential guided waves in piezoelectric semiconductor cylindrical shells and functionally graded piezoelectric semiconductor cylindrical shells are studied by applying the ALPM.To verify the correctness of the method,Lamb-like wave dispersion curves for piezoelectric cylindrical shells with large radius-thickness ratio are calculated by using the ALPM,and compare with the result of the global matrix method.To confirm the efficiency of the method,the wavenumber at a given frequency is calculated respectively via using the LPM and the ALPM,and the calculation times of the two methods are compared.The results show that the 3D spectrum of the piezoelectric semiconductor is symmetrically distributed about the angular frequency axis,which is different from the piezoelectric dielectric material.There is a sensitive range in the regulation of guided wave characteristics by steady-state carrier concentration,and that high steady-state carrier concentrations reduce the attenuation of guided waves.A complex wave mode with low attenuation and high phase velocity will appear by adjusting the radius-thickness ratio and the steady state carrier concentration.Finally,the axially guided wave characteristics of piezoelectric semiconductor cylindrical shells and functionally graded piezoelectric semiconductor cylindrical shells are investigated by employing the ALPM.The effects of circumferential order,radius-thickness ratio and gradient field on the flexural,longitudinal and torsional mode dispersion and attenuation of axially guided waves are analyzed,and the effects of steady-state carrier concentration on the displacement,potential,and perturbation carrier concentration distribution in the longitudinal mode are revealed.The results show that the circumferential order has a significant effect on the phase velocity of the first and second modes of the axial guide wave,which decreases with increasing frequency,and a large circumferential order results in a "break" in the flexural mode attenuation curve at certain frequencies where the attenuation decreases sharply to zero.The radius-thickness ratio has a more significant effect on the low-order axially guided wave modes at low frequencies.The steady-state carrier concentration has almost no effect on the distribution of the perturbed carrier concentration near the inner and outer surfaces.