Modeling and computational simulation for supersonic flutter prediction of polymer/GNP/fiber laminated composite joined conical-conical shells

Abstract

This paper is presented to study the supersonic flutter characteristics of laminated joined conical-conical shells made of epoxy as the matrix and fibers and graphene nanoplatelets (GNPs) as the reinforcements. The mathematical modeling of the shell and the aerodynamic pressure are performed sequentially using the first-order shear deformation theory (FSDT) and the supersonic piston theory incorporating the aerodynamic damping coefficient. The effective elasticity and shear modulus, Poisson’s ratios, and density are estimated using the rule of mixture, Halpin-Tsai model, and micromechanical relations. The governing equations and associated boundary and compatibility conditions are derived utilizing Hamilton’s principle and are solved in the circumferential direction and numerically in the meridional direction via the differential quadrature method (DQM). The natural frequencies and mode shapes are obtained, and the influences of various parameters on the flutter boundaries are examined including the geometrical characteristics of the shell segments, boundary conditions, circumferential wave number, and weight fractions of the GNPs and fibers. It is concluded that by increasing the weight fractions of the fibers and the GNPs, the natural frequencies grow and the aeroelastic stability improves.