Waves In Piezoelectric Cylinder Research Articles

Effects of functionally graded interlayers on dispersion relations of shear horizontal waves in layered piezoelectric/piezomagnetic cylinders

• Dispersive relations of SH guide waves in layered PE/PM cylinders are studied. • Seven kinds of gradient profiles of graded interlayers are considered. • Four kinds of mechanical and electromagnetic surfaces are considered. • Direct integration of graded interlayer is used instead of layer-wise homogenization. • The radial variation of vibration form for low and high order modes is studied. The effects of functionally graded interlayers on dispersion relations of shear horizontal waves in layered piezoelectric/piezomagnetic cylinders are studied. First, the basic physical quantities of elastic waves in piezoelectric cylinder are derived by assuming that the SH waves propagate along the circumferential direction steadily. Then the transfer matrices of the functional graded interlayer and outer piezomagnetic cylinder are obtained by solving the state transfer equations with spatial-varying coefficients. Furthermore, making use of the electro-magnetic surface conditions of the outer cylinder, the dispersion relations for the shear horizontal waves in layered piezoelectric/piezomagnetic cylinders are obtained and the numerical results are shown graphically. Seven kinds of functionally graded interlayers and four kinds of electro-magnetic surface conditions are considered. It is found that the functionally graded interlayers have evident influences on the dispersion relations of shear horizontal waves in layered piezoelectric/piezomagnetic cylinders. The high order modes are more sensitive to the gradient interlayers while the low order modes are more sensitive to the electro-magnetic surface conditions.

Circumferential and Spiral Waves in Piezoelectric Cylinders

Study of the guided waves in piezoelectric cylinders based on a semi-analytical finite element method is presented. In the study, the dispersion equation was formulated as a generalized eigenvalue problem by treating mechanical displacements and electric potential with one dimensional quadratic finite element model through the thickness of the cylinder. Here the general eigenvalue problem is depended on three parameters, namely, the frequency, the axial wave number and the circumferential wave. A non-integer circumferential wave is introduced here for studying the guided spiral wave. A wave spectrum surface is generated to incorporate the guided spiral waves. Cylinders having different geometry and electric boundary conditions are studied but only the results for a thin cylinder with closed electric boundary conditions are presented.