Nomenclature

Symbol	Description
$\rho$	Probability density function
$\theta$	Fiber orientation
$\xi$	Isotropic weighting parameter
$\kappa$	Fiber alignment strength factor
$\mu$	Preferred fiber orientation
$I_0$	Modified Bessel function of the first kind of order zero
$\lambda$	Stretch
$\zeta$	Volume fraction of fibrin
$\delta$	Applied unidirectional deformation
V	Volume between photobleached fibrin gel markers
V 0	Initial volume between photobleached fibrin gel markers
A	Mean cross-sectional area between photobleached fibrin gel markers
A 0	Initial mean cross-sectional area volume between photobleached fibrin gel markers
P	First Piola-Kirchhoff stress
$P_{sr}$	First Piola-Kirchhoff stress for stress-relaxation
$P_{cn}$	First Piola-Kirchhoff stress for constant strain-rate deformation
$E_{sr}$	Tangent modulus for stress-relaxation
$E_{in}$	Initial stress tangent modulus for stress-relaxation
$E_{eq}$	Final stress tangent modulus for stress-relaxation
$E_{cn}$	Tangent modulus for constant strain-rate deformation
$E_{11}$	Green-Lagrange strain in the direction of applied deformation
$k_1$	Fiber modulus in Eq. (2)
$k_2$	Fiber nonlinearity in Eq. (2)
${\beta }_1,{\beta }_2$	Scaling coefficients for the viscoelastic energy in Eq. (2)
${\tau }_1,{\tau }_2$	Time scales of relaxation for the viscoelastic response in Eq. (2)
$k_0$	Modulus of the ECM ground substance in Eq. (6)
$\chi$	Reorientation function defined in Eq. (8)
${\theta }_c$	Direction of principal stretch
${\lambda }_c$	Magnitude of the principal stretch
$\Gamma$	Parameter controlling the non-affine reorientation