Wave propagation in rotating functionally graded GPL-reinforced cylindrical shells based on the third-order shear deformation theory

In this paper, wave propagation, in a rotating cylindrical thick shell, is analytically studied. The shell is composed of epoxy as the matrix enriched with functionally graded (FG) graphene nanoplatelets (GPLs) as the reinforcement. The effective material properties are estimated using the Halpin-Tsai model and rule of mixture. By considering constant angular velocity, the set of governing equations are derived using Hamilton's principle within the framework of third-order shear deformation theory (TSDT), incorporating effects of the Coriolis and centrifugal accelerations along with initial hoop tension. Variations of the phase velocity of forward and backward waves versus longitudinal wave numbers are investigated for various involved parameters such as circumferential wave number, rotating speed, geometrical parameters of the shell as well as the mass fraction, distribution pattern and width of the GPLs. The results indicate as the rotating velocity of the shells increases, the phase velocity of the forward traveling wave increases though the phase velocity of backward one decreases. Also, subjoining a small amount of GPLs to the epoxy significantly improves the phase velocity for both forward and backward modes, especially when the GPLs are distributed near the inner and outer surfaces of the shell.