Zhong Chao

Study of Vibration Characteristics about Two-Layered Composite Pile

In this study, two-layered composite piles are made based on the multi-mode coupling principle. The relationship between the bandwidths of 1–3 composites with different thicknesses and those of two-layered composite piles are analyzed by finite element simulation and experimental measurement. The simulation results agree well with the results of the experiment. Change rules for the resonance frequency difference and for the bandwidth of the composite pile are obtained by adjusting the thickness difference of the two composites, and the errors between the simulation and experiment are analyzed.

The Analysis of Piezoelectric Tube Stack for Radial Vibration Frequency

According to equivalent circuit principle, piezoelectric tube stack equivalent circuit is derived by the admittance of single piezoelectric thin tube, and the resonance frequency of piezoelectric tube stack for radial vibration is also calculated. The relationship between resonance frequency of radial vibration mode and average radius, thickness and height are obtained from analytical calculation. Analytical calculation and experiment results are compared, and they match well with each other.

Analyses for Thickness Vibration of Piezoelectric Ring

The thickness vibration of piezoceramic ring is investigated by theoretical analysis, numerical simulation, and experimental measurement. Based on the piezoelectric constitutive equations and the hypothesis that a ring has no strain in circumference when vibrating, the thickness vibration mode of ring is treated as a radial longitudinal extended vibration equivalently, the equations was simplified and the resonant frequency of thickness vibration is derived. The resonant frequency is also simulated with finite element software and measured by Impedance Analyzer. Theoretic calculation of resonant frequency is compared with the simulation and measurement. The errors between them are analyzed.