▎ 摘　　要

Graphene platelets (GPLs) can be used to enhance mechanical and electric properties of the polymer polyvinylidene fluoride (PVDF), which efficiently controls and improves dispersion characteristics of wave motion in piezoelectric composite structures. Based on the first order shear deformation shell theory and the higher-order spectral elements, this paper proposes a semi-analytical formulation to investigate wave characteristics in the piezoelectric polymer nanocomposite cylindrical shell. The cylindrical shell is composed of PVDF reinforced with graphene platelets that are dispersed along the thickness direction, following various functionally graded patterns UD, FG-X and FG-O. Governing equation of waves in the piezoelectric composite shell is derived from Hamilton's principle. By employing the Fourier transform, a second-order polynomial eigenvalue problem is obtained for wave analysis in frequency domain. Comparisons with other methods indicate that the present approach has the higher efficiency and accuracy on computation. Then, the study of significant parameters are conducted for analyzing the effects on wave propagation and the results show that dispersion behaviors of the piezoelectric nanocomposite shell are improved apparently by the addition of a small amount of GPLs. The increasing content of GPLs promotes the propagation of elastic waves and the richer concentration on the boundaries of the shells is beneficial to only the out-of-plane modes. Meanwhile, size parameters of GPLs provide an efficient means for the modulation of wave characteristics in nanocomposite shells. It is envisaged that the present work can provide guidelines to develop novel smart nanocomposites and structures.