Effect of variable thickness on the aeroelastic stability boundaries of truncated conical shells

Abstract

The flutter characteristics of a truncated conical shell with variable thickness exposed to a supersonic fluid flow are studied in this study. The first-order shear deformation theory (FSDT) is employed to model the shell and the linear piston theory is utilized to evaluate the aerodynamic pressure. The boundary conditions and governing equations are formulated based on Hamilton’s principle. An exact solution is presented in the circumferential direction and the differential quadrature method (DQM) is hired to present an approximate solution in the meridional direction. A general two-parameter power-law equation is considered for thickness variation in the meridional direction and the effects of these coefficients on the flutter boundaries are examined. It is observed that utilizing the conical shells with uniform thickness is not an optimum design and to improve the aeroelastic stability of the conical shells it is better to increase the thickness of the shell from the small radius of the shell to the large one. As the novelty of the presented work, it can be claimed that it is the first attempt to examine the flutter characteristics of conical shells of nonuniform thickness and the results can be utilized to provide optimum designs for aerovehicles.