Implementation of Anisotropic Hyperelastic Materials in NL-SBFEM Framework: The HGO Model

This paper presents the first implementation of anisotropic hyperelastic materials within the NL-SBFEM framework. The Holzapfel-Gasser-Ogden (HGO) model is integrated through the modular material interface to capture fiber-reinforced tissue behavior. Validation against ABAQUS shows excellent agreement with errors below 2% across different fiber orientations. Parametric studies demonstrate the framework’s ability to capture complex anisotropic responses including fiber dispersion effects and nonlinear stiffening behavior. The modular architecture enables future extensions to other anisotropic models and establishes NL-SBFEM as a viable alternative for biomechanical applications requiring boundary-only discretization.