Fig. 7.

Different sets of material constants can fit an experimental curve well. The constants for line in green are: c₁ = 9.495 × 10⁻⁸, D₁ = 2.155 kPa, D₂ = 13.570 and γ = 5.6%; and those for black line are: c₁ = 0.650, D₁ = 2.167 kPa, D₂ = 13.499 and γ = 5.5%.