Analysis Of Large Deformation For The Inflatable Fabric Structure Under Water Using FEM

Due to the richness in natural resource, the ocean has become more and more countries' important strategic target. The 21st century is the sea centuries. The diving instrument is indispensable for ocean exploration exploitation and lifesaving underwater. Many countries have been trying to develop this technology. The level of the development of the diving instrument is also seen as a symbol of a country's polytechnic strength.The design methods of space structure were creatively used for designing our under water structures. The dissertation proposes a kind of designable conceive for diving instrument which is different from others. High strength fabric material is used in this structure, the structure we design is composed by two concentric spherical surfaces, stiffness patches are used to connect this two concentric spherical surfaces, and aerate the high-pressure gas in the space which outside the internal sphere panel and inside the external sphere panel, so, the external sphere panel will be of large stiffness to resist the outer pressure, and the air pressure inside the internal sphere panel maintain normal pressure. Following these design, the apparatus inside the internal sphere panel could work safely.For convenience, a series of simplifications to the structure are adopted in this dissertation, we use regular dodecahedron to instead of the sphere panel, so the analysis for the structure is simplified to study a pentagonal curvy structure. At the same time, because fabric materials have membrane stiffness but no bending stiffness, we use membrane element to simulate fabric structure. This article mainly discussed the mechanical performance of membrane structure with different structural and mechanical parameters. The displacement and stress for membrane structure under different loads were also studied. Moreover, the impact of ratio of rise to span and material module on the deformations and stress...