Guided waves propagation in sandwich cylindrical structures with functionally graded graphene-epoxy core and piezoelectric surface layers

As an ideal reinforcing nanofiller, graphene platelets (GPLs) can significantly improve physical properties of nanocomposites, which have attracted considerable attention for design and development of advanced lightweight nanocomposite structures in engineering. In this paper, a sandwich cylindrical structure is considered for dispersion properties of wave propagation by axisymmetric isogeometric analysis (IGA). The sandwich structure is composed of a functionally graded (FG) nanocomposite core and piezoelectric surface layers. Graphene platelets are dispersed in the interlayer by three typical distribution patterns through the thickness. In virtue of the symmetry and the advantages of isogeometric analysis, the sandwich cylindrical structure can be described by one-dimensional representation along the radial direction. Based on Hamilton's principle, parameterized governing equation for wave propagation is obtained with the non-uniform rational B-splines (NURBS), which leads to an second-order eigenvalue problem. The modified wave finite element (WFE) method and the Chebyshev spectral element (SE) method are utilized to verify the reliability and accuracy of this approach. Then, the effects of several significant parameters of GPLs and geometric sizes of the sandwich structure on wave propagation characteristics are discussed in details. The results of this study are beneficial to deeply understanding and control of wave propagation in advanced piezoelectric composites for the applications in structural health monitoring and nondestructive evaluation.

Automated summary

This paper investigates the dispersion properties of graphene platelets in a sandwich structure and their effect on wave propagation through isogeometric analysis. The parameterized governing equation for wave propagation is obtained based on Hamilton's principle and non-uniform rational B-splines (NURBS), resulting in a second-order eigenvalue problem. The reliability and accuracy of this approach are verified using the modified wave finite element (WFE) method and the Chebyshev spectral element (SE) method. The study provides insights into controlling wave propagation for structural health monitoring and nondestructive evaluation applications.