Shear deformations in inflated cylindrical beams: An old model revisited

The paper considers the effects of shear deformations on the load-displacement response of pressurized thin-walled circular-cylindrical beams subjected to lateral loads. A classical structural model, able to account for the inability of the wall's constituent material to withstand compressive stresses, is used to model the nonlinear behavior of partially wrinkled beams under simultaneous bending and shear. Particular attention is devoted to accurate determination of the shear stiffness within the wrinkled zones of the beam. The system of nonlinear equations governing the equilibrium of the inflated beams after the onset of the post-critical stage is amenable to numerical solution via standard incremental-iterative algorithms, as long as the wrinkling of the cross sections is small or moderate. Application of the proposed model to some well-documented problems drawn from the literature serves to illustrate the proposed algorithm's potential.