Uni-axial tensile mechanical properties and elastic constants of airship envelope material

The experiment results of uniaxial tension of airship envelope material Uretek5876 were analyzed in seven in-plane directions including 0°, 15°, 30°, 45°, 60°, 75°, 90°, which provided the law of residual strain and elasticity modulus with cycle inder. The modulus obtained from the theory of single layer board does not adapt to multi-layer pressure membrane material. VIC-2D digital speckle technique was used in tensile process to obtain the displacement field and strain field. Based on displacement field, the Poisson's ratio of Uretek 5876 was obtained. Strain field was not only used to analysis tensile failure mechanism, but also can forecast the position and type of fracture. The uniaxial tensile strength was tested by two kinds of specification of the sample, and the sample 3 was found to be more proper to response the actual strength of Uretek 5876. The work in this paper provides reference value for the design and analysis of the airship structure.