Skip to main content
. Author manuscript; available in PMC: 2023 Aug 29.
Published in final edited form as: J Biomech Eng. 2020 Jan 1;142(1):011003. doi: 10.1115/1.4044235

Table 1.

Material constants for Guccione’s model, derived from an equibiaxial protocol [20]

c1 (kPa) C 2 C 3 C 4 R2-FD R2-XD
1.50 (0.10) 28.69 (0.80) 45.98 (0.69) 0.00 (1.82) 0.99 1.00

The strain energy function W was expressed in LS-Dyna as W=(C1/2)[exp(c2Eθ2+c3(Ez2+Er2+Erz2+Ezr2)+c4(Eθz2+Eθr2+Erθ2+Ezθ2))1]+(P/2)(J1), where c1c4 are the material constants, Exy are the deformations (green strain components modified to only include the effects of volumetric work), and xy refers to the subscripts θ, z, and r corresponding to the circumferential, through-thickness, and radial directions, respectively. P is a Lagrange multiplier numerically enforcing the material nearincompressibility whereby J, the determinant of the deformation gradient tensor, is almost equal to 1. The values in parentheses report half the span of the 95% confidence interval. R2-FD and R2-XD represent Pearson’s product–moment correlation coefficients in fiber and cross-fiber directions, respectively.