Finite element modelling of orthotropic material behaviour in pneumatic membranes

In this paper, we develop a model to describe the hyperelastic material behaviour of pneumatic membranes reinforced with roven-woven fibres. A generalized stored energy function is developed via a series of loading tests on a representative sample of this composite material. The exponents in the effective law are chosen so as to fulfil basic restrictions, discussed in the body of the paper, as well as to match certain experimental values. Numerical examples demonstrate the application of the approach to inflated rubber matrix materials, as well as laminated shells.