Table 2.

Strain-energy functions of three elastic models (Maas et al., 2014).

Elastic model	Strain-energy function	Parameter description
Linear isotropic elastic	$W=\frac{1}{2}\lambda {(\mathit{\text{tr}}E)}^2+\mu \mathit{\text{tr}}(E^2)$	E: Euler-Lagrange strain tensor λ and μ: Lamé parameters J: determinant of the deformation gradient tensor Ĩ1 and Ĩ2: first and second invariants of the deviatoric right Cauchy-Green deformation tensor c1 and c2: material parameters K: bulk modulus
Neo-Hookean compressible Material	$W=\frac{\mu }{2}({Ĩ}_1-3)-\mu \text{ln}J+\frac{\lambda }{2}{(\text{ln}J)}^2$
Uncoupled Mooney-Rivlin material	$W=c_1({Ĩ}_1-3)+c_2({Ĩ}_2-3)+\frac{1}{2}K{(\mathit{\text{ln}}J)}^2$