Cyclic tensile loading and unloading tests were performed to obtain a hyperelastic material model of the TPV. The fifth loading stress-strain curve was selected for fitting the model to remove the effect of stress-softening, so called Mullin’s effect, of the TPV material. Because TPV is a solid elastomer with compressibility, the Jel Jacobian value is 1. Therefore, the strain energy of the Mooney-Rivlin model can be represented as Equation (12), where I1 and I2 are 1st and 2nd invariant of the right Cauthy-Green strain tensor. The fitting results of the material constants for C10, C01 are listed in Table 5.