Theory Manual Version 3.4
$\newcommand{\lyxlock}{}$
Subsection 5.3.7: Fiber with Exponential Power law Up Section 5.3: Nearly-Incompressible Materials Subsection 5.3.9: Tension-Compression Nonlinear Orthotropic

### 5.3.8 Fung Orthotropic

The hyperelastic strain energy function for a Fung Orthotropic material is given by [33, 32] where Here, and , where are orthonormal vectors that define the initial direction of material axes. The orthotropic Lamé coefficients should be chosen such that the stiffness matrix, is positive definite.
Subsection 5.3.7: Fiber with Exponential Power law Up Section 5.3: Nearly-Incompressible Materials Subsection 5.3.9: Tension-Compression Nonlinear Orthotropic