Mechanics of Inflatable Fabric Beams
In this paper we present a summary of the behaviour of inflatable fabric beams. Three kind of beams are studied: inflatable flat panels, tubes and a torus. Deflections of inflated beams are established by satisfying the following requirements : equilibrium equations must be written in the deformed state (to take into account the following forces due to the internal pressure) and Timoshenko’s assumptions must be used to describe the kinematics of the beam. Analytical studies on inflatable fabric beams are presented and inflatable fabric beam finite elements are described. The stiffness matrixes takes into account the inflation pressure. Finite element analysis of a pinched torus is displayed. Experiments show that one can make an analogy between usual plastic hinges and pneumatic hinges which appear in the shapes of inflatable beams. Shakedown analysis is therefore used to calculate limit loads of inflatable fabric beams. First results on the dynamic behaviour of an inflated beam are finally shown. Comparisons between experimental and numerical results prove the accuracy of shakedown and finite element analysis for solving problems of inflatable fabric beams.