Abstract: Based on fiber reinforced continuum mechanics theory, a simple hyperelastic constitutive model is developed to characterize the anisotropic nonlinear material behavior of woven composite fabrics under large deformation during forming. The strain energy functions for the hyperelastic model is decomposed into two parts representing the tensile energy from weft and warp yarn fiber stretches and shearing energy from fiber-fiber interaction between weft and warp yarns, respectively. The equivalent material parameters in the hyperelastic constitutive model can be obtained by matching experimental load-displacement data of uni-axial tensile and bias-extension tests on woven composite fabric. The model is validated by implementing numerical simulations on a hemispherical stamping of a square balanced plain weave composite fabric at room temperature. Comparisons between simulation results and experimental data show that the proposed hyperelastic model can effectively characterize the anisotropic material behavior of woven composites under large deformation. The proposed model is simple and easy for material parameter determination. The development of this anisotropic fiber reinforced hyperelastic model is critical to the numerical simulation and processing optimization of woven composites forming.

Key words: Anisotropy, Constitutive modeling, Finite element analysis, Hyperelastic, Stamping simulation, Woven composite fabrics