Virtual Fiber-Based Constitute Model for Anisotropic Material Design

In order to expand types of anisotropic hyperelastic virtual materials for elastic bodies simulation in graphics, this paper established a virtual fiber-based constitutive model. Firstly, the strain energy density function of hyperelastic body was decomposed into fiber addition form of axial, shearing and volumetric component based on energy additivity. Secondly, strain measurement of each component for a single fiber was established. Finally, stress expression of each component was deduced. Simulation experiments used tetrahedral nonlinear finite element method (FEM), semi-implicit time integration and CPU-based serial algorithm to test effects of nonlinear energy function and fiber weight combination on the stiffness, Poisson effect and anisotropic axial characteristics in different scenarios. Results show that the virtual fiber-based model displays desirable physical properties with adopted parameter setting, and is suitable for large deformation simulation. Compared with existing transverse isotropic model, this model also possesses more abundant adjustability.