Theoretical and experimental investigation on helium leakage characterization of flexible film-fabric laminated composites

Flexible film-fabric laminated composites with low-density and high-performance are important envelope materials in stratosphere aerostats. In this paper, a multilayer leak model is used to predict the helium leak rate of the virgin samples by the Fick's law, which shows a good agreement with experimental data. The influences of mechanical damage, ultraviolet radiation and intense ozone corrosion on the Young's modulus and the permeability of envelop materials are investigated in experiment, which are confirmed by means of damage-induced helium leakage models. Finally, helium leakage mechanisms of flexible film-fabric laminated composites are analyzed.