Reliability of inflatable structures: challenge and first results

Inflatable structures are part of the family of tensioned textile membrane structures. The operating principle is common for all these type of structures: the stiffness of the structure relies on the tensioning of the membrane, which is generally provided by a mechanical device in the case of tensile structures, and by setting the pressure in the case of pneumatic structures. These structures are the subject of a European standardisation process to harmonise the methods of calculation and design. We propose here a first reliability study on a two parallel inflatable beams structure which can be used as a footbridge. The serviceability limit states (SLS) and ultimate limit state (ULS) are defined. The reliability analysis is conducted with the First Order Reliability method, providing reliability indices as well as sensitivity factors.