effects of stiffening parameters on axial buckling of stiffened composite shells

in the present paper, effects of some parameters of stiffeners on the cylindrical composite shell have been studied on the axial buckling. the stiffeners are arranged in equal intervals and have the same cross-sectional area.to calculate the stiffness of these elements, the reaction between shell and stiffeners was considered.in order to solve the special buckling of these structures, the ritz method was used and results of numerical simulations were compared. boundary conditions of the shells were assumed as fixed or simply supported on both ends. finally, the effects of geometry and type of stiffeners, their orientations with respect to shell axis and their numbers, shell thickness and material, stacking sequence of layers and types of boundary conditions have been investigated. shell thickness and i and t profiles for stiffeners have maximum effects on increasing the buckling loads. with increasing angle of the stiffeners, the buckling load decreases.