Figure 3:

Coordinate and fiber axes in the reference and current configuration, ${\Omega }_0$ and ${\Omega }_t$ mapped from the parametric domain $\hat{\Omega }$. Maps ${\pi }_0$ and ${\pi }_t$ are defined in Equation 6, coordinate axes (in the reference domain) are defined in Equation 3, and circumferential and radial fiber directions $G_c$ and $G_r$ are defined in Equation 4. Note that an asterisk denotes that a parameter is fixed.