Evaluation of material model parameters of vaginal tissue with different fiber orientation

Vaginal tissue is known to be stiffer when load is applied in the longitudinal direction of its fibers rather than the transverse direction. However, little attention has been paid to the differences in the material parameters that characterize these tissues' behavior. The goal of this study was to evaluate the differences of vaginal tissue's material parameters for constitutive modeling. For this purpose, experimental data from previous uniaxial tensile tests, in the longitudinal and transverse directions, of anterior and posterior vaginal wall samples were used. The material parameters were determined for Weiss modified and Mooney-Rivlin material models using an analytical method. As expected, different mechanical properties reflected different material parameters. Weiss modified material model confirmed to be suitable for modeling the longitudinal direction but inaccurate in the transverse direction, whereas Mooney-Rivlin's revealed to be more adequate on modeling the transverse direction.