Coated F-12 aramid fabric can be used as the balloon envelopes material because of the high strength and light weight performance. In this paper, a multiscale non-orthogonal material model was established to capture the tensile properties of F-12 fabric with and without polyethylene terephthalate-aluminum (PET-Al) coating. Off-axial monotonic tensile tests were carried out to validate the material model. The nonlinearity and anisotropic properties of the coated and uncoated fabrics were investigated. In this model, the stress was obtained based on the equilibrium equations and yarn constitutive model in mesoscale. The mesoscale configuration was observed through optical microscope and SEM. The material orientation was aligned with the yarn directions and the stress was updated in real time. The material model was implemented by user material subroutine in ABAQUS and simulate fabric off-axial tensile test. In addition, a theory model to calculate the elastic property of the fabric was also set up using the mesoscale deformation mechanism. The simulation results were compared with the test and theory results. Results suggest that simulation results were agree well with test results. The fabrics were nearly linearity in weft direction, while the stressstrain curve exhibited obvious nonlinearity in warp direction. The tensile modulus of the fabric showed orthotropic behaviour rather than the strength. The coating can affect the strength and failure model of F-12 fabric. Yarn slip was the mostly failure model in uncoated fabric while break in coated fabric. Research in this study provides certain reference in analysis and design for balloon envelops
