On the buckling resistance of grid-stiffened composite conical shells under compression

• Buckling behavior of grid-stiffened composite conical shell is studied based on FSDT. • Numerical and analytical analysis are carried out on the stiffened composite conical shell with helical ribs. • The analytical model is capable of predicting the buckling behavior of grid-stiffened composite conical shells. • The effect of various design parameters on the buckling characteristics have been investigated. In this paper, an analytical approach has been employed to investigate the global buckling behavior of grid-stiffened composite conical shells with cross stiffeners, on the basis of the first-order shear deformation theory (FSDT). First, the equivalent stiffness parameters of the stiffening structure have been derived through smearing the forces and moments on a typical unit cell taking the shear effects into consideration. Then, superimposing this stiffness contribution with those of the skin, the equivalent stiffness associated with the whole structure is determined. The power series method has been used to solve the equations governing the global buckling of the grid-stiffened composite conical shells. The obtained analytical results have been verified using a 3D finite element model built in ABAQUS software. Furthermore, the influences of some important design parameters such as the stiffener orientation, skin lamination and semi-vertex angles have been investigated on the buckling characteristics of the examined structure. The presented results are novel and can be used for further relevant investigations.