“…We provide a brief description of the model to facilitate the discussion; details may be found in Rausch and Humphrey (2016). In this model, the strain energy density function is represented in the following form:
where W g ( C ) is the strain energy density of the ground substance, C is the right Cauchy-Green tensor, φ ( θ , Φ) is the fiber bundle orientation distribution function with ( θ , Φ) representing the azimuthal and polar angles, and W f ( C , N ( θ , Φ)) is the strain energy density of the fiber bundles oriented in the direction N ( θ , Φ).…”