Free vibration and supersonic flutter analyses of a sandwich cylindrical shell with CNT-reinforced honeycomb core integrated with piezoelectric layers

Abstract

n this research, the free vibration and supersonic flutter analyses of a cylindrical sandwich shell with a reinforced honeycomb core (RHC) integrated with piezoelectric face sheets are investigated. The core is a honeycomb structure enriched with fibers and carbon nanotubes (CNTs). The layers of the shell are modeled based on the Cooper-Naghdi shell theory and the continuity conditions between the layers are considered. The aerodynamic pressure of the supersonic flow is modeled using the linear piston theory. Hamilton’s principle is used to derive the governing equations. A semi-analytical solution is presented including an exact solution in the circumferential direction followed by a numerical solution in the longitudinal direction via the differential quadrature method (DQM). The effects of several parameters on the frequencies, the corresponding damping coefficients, and the critical aerodynamic pressure are investigated. It is concluded that improving the stiffness of the honeycomb core with the CNTs does not necessarily improve the aeroelastic stability of the shell. The presented results can be used in the design and analysis of aerospace structures.