On network descriptions of mechanical and optical properties of rubbers

The non-Gaussian full network model for rubber elasticity is reformulated in a more efficient and more micromechanics-motived manner. Based on such a full network description, a so-called full network model for rubber photoelasticity is proposed, by introducing directional polarizabilities into the individual links of the idealized randomly jointed chain. This optical theory can be used to study the optical properties or birefringence-strain behaviour of rubbers in arbitrary three-dimensional deformation states. Detailed comparisons with two approximate models, namely the classical three-chain model and an eight-chain model for rubber photoelasticity, are provided for different types of deformation. The predicted numerical results are compared with experimental data found in the literature.