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Adhesive junction modelling of a super-pressure balloon

Abstract Long duration super-pressure balloon design and manufacturing is a great challenge for the Centre National d'Etudes Spatiales in scientific ballooning. They are made of 50 μm thick polymer films polyethylene terephtalate/polyamide/polyethylene terephtalate which are joined with 23 μm thick adhesive polyethylene terephtalate bands. To date, during flight missions, a major problem appears: some balloons explode prematurely. This is why this study deals with the mechanical behaviour of the stratospheric pressurized balloons and particularly with the assembly of the constitutive films material. First, a nanoindentation test campaign makes it possible to identify the elastic properties of the materials at two different temperatures. Then, a nominal assembly is simulated in two stages: two-dimensional and three-dimensional. Finally, the factorial design method combined with finite-element simulations was used to study the influence of the various conception parameters on the mechanical behaviour of the assembly.