Boundary layer theory for the buckling and postbuckling of an anisotropic laminated cylindrical shell, Part III: Prediction under torsion

A boundary layer theory for the buckling and postbuckling of anisotropic laminated thin shells is extended to the loading case of torsion. A singular perturbation technique is employed to determine the buckling load and postbuckling equilibrium paths. The numerical illustrations concern the postbuckling behavior of twist, perfect and imperfect, anisotropic laminated cylindrical shells with different values of shell parameters and stacking sequence. The new finding is that there exists a shear stress along with an associate compressive stress when the anisotropic shell is subjected to torsion, and all the results published previously need to be re-examined. The results confirm that the effect of the boundary layer on the solution of a twist shell is of the order ε5/4. The postbuckling equilibrium path is unstable for the moderately long shell subjected to torsion and the shell structure is less sensitive to initial imperfections than in the case of axial compression.