ACF	Cross-sectional area of the (i.e., uniform cylindrical) fibril
C	C-terminus (containing the carboxyl group) of the collagen molecule
COMP	Cartilage oligomeric matrix protein
D	The D period of the collagen fibril
DD1	Population of fibrils with smaller diameter (relative to DD2)
DD2	Population of fibrils with larger diameter (relative to DD1)
ECF	Tensile stiffness of the collagen
F	Axial force generated within the collagen molecule
Fmax	Breaking force of the collagen molecule
Gm	Shear modulus of the interfibrillar matrix
H	Constant in the differential equation of the shear-lag model
Lcrit	Critical length for fibril fracture
LCF	Half-length of the fibril
LCL	Contact length between two adjacent collagen molecule
LTC	Length of the collagen molecule
ml	Collagen mass per unit length
M	Mass of a collagen molecule
N	Number of molecules intersecting a fibril cross-section (through an overlap region)
N	Amino-terminus (containing an amine group) of the collagen molecule
q	Fibril aspect ratio
(r,θ,z)	Radial, azimuthal and axial coordinates, respectively, of the cylindrical polar coordinate system
rm	Radius of the matrix surrounding the fibril
r0	Radius of the (uniform cylindrical) fibril
uCF	Axial displacement of the fibril at that point within the fibril
um	Axial displacement of the interfibrillar matrix at the same point if the fibril were not presence
uE	Strain energy density, relates to the tissue resilience
uF	Strain energy density, relates to the tissue rupture
vc	Poisson’s ratio of the tissue
vCF	Poisson’s ratio of the collagen fibril
vm	Poisson’s ratio of the interfibrillar matrix
VCF	Volume fraction of collagen fibrils
Vm	Volume fraction of interfibrillar matrix
Z	Normalized axial coordinate