Pressurized membranes for structural use: interaction between local effects and global response

This paper is aimed to assess the non-linear elastic response of an inflatable cylindrical beam through a simple mechanical model recently proposed by the authors1 to study the equilibrium shapes of highly pressurized elastic membranes. The local geometric nonlinearities due to the wrinkling of the membrane are taken into account by means of an equivalent physical non-linearity, assuming a two-states constitutive law for the material: when a fiber is stretched (the active state), its response is elastic, while when the fiber is contracted, no compressive force can be engendered in it (the passive state). The evolution of the wrinkled regions and the distribution of longitudinal and transverse stresses in the membrane are accurately determined for increasing levels of loads, up to the collapse. The numerical results, obtained through an expressly developed incremental-iterative algorithm, are then compared with the experimental ones available in the literature.