Buckling analysis of a laminated cylindrical shellunder torsion subjected to mixed boundary conditions

A new e.cient method is developed in this paper for buckling analysis of a cross!ply laminated cylindrical shell under torsion subjected to mixed boundary conditions[ The transverse shear is taken into account by a _rst!order theory with a shear correction factor of 4:5[ The mixed boundary conditions include conditions in forces as well as conditions in displacements\ and these forces and displacements are selected as basic unknowns[ The other displacements and forces are expressed in terms of the basic unknowns by taking inverse of a matrix composed of operators[ The equations of buckled equilibrium in terms of the basic unknowns are solved with double trigonometric series which satisfy the mixed boundary conditions[ Com! parison of the obtained numerical results with those given in the literature based on completely clamped boundary conditions checks with the fact that the mixed boundary conditions yield appreciably lower buckling load and less circumferential wave number than the completely clamped boundary conditions[ The curves in the _gures show how the di}erence in buckling loads between the two kinds of boundary conditions varies when the length and thickness of the shell vary