Skip to content

Log Variables

The following log variables are available in FEBio:

variable description module
alx x-component of angular acceleration solid
aly y-component of angular acceleration solid
alz z-component of angular acceleration solid
avg Average of another log variable over domain core
ax x-component of center of mass acceleration solid
ay y-component of center of mass acceleration solid
az z-component of center of mass acceleration solid
c the element-averaged actual concentration of solute in a biphasic-solute material. solute
c1 the element-averaged actual concentration of solute with index 1 in a multiphasic material. solute
c1_integral the integral of the actual solute 1 concentration over the domain. multiphasic
c2 the element-averaged actual concentration of solute with index 2 in a multiphasic material. solute
c2_integral the integral of the actual solute 2 concentration over the domain. multiphasic
c3 the element-averaged actual concentration of solute with index 3 in a multiphasic material. solute
c3_integral the integral of the actual solute 3 concentration over the domain. multiphasic
c4 the element-averaged actual concentration of solute with index 4 in a multiphasic material. solute
c4_integral the integral of the actual solute 4 concentration over the domain. multiphasic
c5 the element-averaged actual concentration of solute with index 5 in a multiphasic material. solute
c5_integral the integral of the actual solute 5 concentration over the domain. multiphasic
c6 the element-averaged actual concentration of solute with index 6 in a multiphasic material. solute
c6_integral the integral of the actual solute 6 concentration over the domain. multiphasic
c7 the element-averaged actual concentration of solute with index 7 in a multiphasic material. solute
c7_integral the integral of the actual solute 7 concentration over the domain. multiphasic
c8 the element-averaged actual concentration of solute with index 8 in a multiphasic material. solute
c8_integral the integral of the actual solute 8 concentration over the domain. multiphasic
ce1 effective concentration of solute with index 1 in current configuration solute
ce2 effective concentration of solute with index 2 in current configuration solute
ce3 effective concentration of solute with index 3 in current configuration solute
ce4 effective concentration of solute with index 4 in current configuration solute
ce5 effective concentration of solute with index 5 in current configuration solute
ce6 effective concentration of solute with index 6 in current configuration solute
ce7 effective concentration of solute with index 7 in current configuration solute
ce8 effective concentration of solute with index 8 in current configuration solute
cF fixed charge density in current configuration solute
constrained volume The volume inside the constrained volume of a volume constraint. solid
contact area The total contact area of the contact interface this surface belongs to. solid
contact gap The gap (separation) of the contact interface this surface belongs to solid
contact pressure The normal contact pressure of the contact interface this surface belongs to solid
contact_traction.x The x-component of the contact traction on the face solid
contact_traction.y The y-component of the contact traction on the face solid
contact_traction.z The z-component of the contact traction on the face solid
crc referential mass-concentration of solute in a biphasic-solute material. solute
cxxxx xxxx component of spatial elasticity tensor (a.k.a. c11) solid
cxxxy xxxy component of spatial elasticity tensor (a.k.a. c14) solid
cxxxz xxxz component of spatial elasticity tensor (a.k.a. c16) solid
cxxyy xxyy component of spatial elasticity tensor (a.k.a. c12) solid
cxxyz xxyz component of spatial elasticity tensor (a.k.a. c15) solid
cxxzz xxzz component of spatial elasticity tensor (a.k.a. c13) solid
cxyxy xyxy component of spatial elasticity tensor (a.k.a. c44) solid
cxyxz xyxz component of spatial elasticity tensor (a.k.a. c46) solid
cxyyz xyyz component of spatial elasticity tensor (a.k.a. c45) solid
cxzxz xzxz component of spatial elasticity tensor (a.k.a. c66) solid
cyyxy yyxy component of spatial elasticity tensor (a.k.a. c24) solid
cyyxz yyxz component of spatial elasticity tensor (a.k.a. c26) solid
cyyyy yyyy component of spatial elasticity tensor (a.k.a. c22) solid
cyyyz yyyz component of spatial elasticity tensor (a.k.a. c25) solid
cyyzz yyzz component of spatial elasticity tensor (a.k.a. c23) solid
cyzxz yzxz component of spatial elasticity tensor (a.k.a. c56) solid
cyzyz yzyz component of spatial elasticity tensor (a.k.a. c55) solid
czzxy zzxy component of spatial elasticity tensor (a.k.a. c34) solid
czzxz zzxz component of spatial elasticity tensor (a.k.a. c36) solid
czzyz zzyz component of spatial elasticity tensor (a.k.a. c35) solid
czzzz zzzz component of spatial elasticity tensor (a.k.a. c33) solid
D damage variable (or sum of damage variables in solid mixtures) solid
damage_1 the damage (or fraction of broken bonds) of solid component 1 in a solid mixture material. solid
damage_2 the damage (or fraction of broken bonds) of solid component 2 in a solid mixture material. solid
damage_3 the damage (or fraction of broken bonds) of solid component 3 in a solid mixture material. solid
damage_4 the damage (or fraction of broken bonds) of solid component 4 in a solid mixture material. solid
damage_5 the damage (or fraction of broken bonds) of solid component 5 in a solid mixture material. solid
damage_6 the damage (or fraction of broken bonds) of solid component 6 in a solid mixture material. solid
damage_7 the damage (or fraction of broken bonds) of solid component 7 in a solid mixture material. solid
damage_8 the damage (or fraction of broken bonds) of solid component 8 in a solid mixture material. solid
devsed deviatoric strain energy density solid
discrete element elongation The discrete element's elongation (i.e. current length minus initial length) solid
discrete element force The scalar force along the element's axis. solid
discrete element stretch The discrete element's stretch (i.e. ratio of current length over initial length) solid
E1 first eigenvalue of Green-Lagrange strain tensor solid
E2 second eigenvalue of Green-Lagrange strain tensor solid
E3 third eigenvalue of Green-Lagrange strain tensor solid
effective left Hencky The effective (or von-Mises) norm of the left Hencky tensor solid
effective left stretch The effective (or von-Mises) norm of the left stretch tensor solid
effective right Hencky The effective (or von-Mises) norm of the right Hencky tensor solid
effective right stretch The effective (or von-Mises) norm of the right stretch tensor solid
effective strain the effective (or von-Mises) norm of the Green-Lagrange strain tensor. solid
effective stress the effective (or von-Mises) norm of the Cauchy stress tensor solid
esxx The xx component of the solid stress of a biphasic material biphasic
esxy The xy component of the solid stress of a biphasic material biphasic
esxz The xz component of the solid stress of a biphasic material biphasic
esyy The yy component of the solid stress of a biphasic material biphasic
esyz The yz component of the solid stress of a biphasic material biphasic
eszz The zz component of the solid stress of a biphasic material biphasic
EulerX X-Euler angle solid
EulerY Y-Euler angle solid
EulerZ Z-Euler angle solid
ex xx-component of the infinitesimal strain solid
Ex xx-component of the Green-Lagrange strain solid
exy xy-component of the infinitesimal strain solid
Exy xy-component of the Green-Lagrange strain solid
exz xz-component of the infinitesimal strain solid
Exz xz-component of the Green-Lagrange strain solid
ey yy-component of the infinitesimal strain solid
Ey yy-component of the Green-Lagrange strain solid
eyz yz-component of the infinitesimal strain solid
Eyz yz-component of the Green-Lagrange strain solid
ez zz-component of the infinitesimal strain solid
Ez zz-component of the Green-Lagrange strain solid
facet area The area of the surface facet in the current configuration core
fax x-component of fluid acceleration fluid
fay y-component of fluid acceleration fluid
faz z-component of fluid acceleration fluid
fd fluid density fluid
Fde.x The x-component of the discrete element's force vector. solid
Fde.y The y-component of the discrete element's force vector. solid
Fde.z The z-component of the discrete element's force vector. solid
fdxx xx-component of fluid rate of deformation fluid
fdxy xy-component of fluid rate of deformation fluid
fdxz xz-component of fluid rate of deformation fluid
fdyy yy-component of fluid rate of deformation fluid
fdyz yz-component of fluid rate of deformation fluid
fdzz zz-component of fluid rate of deformation fluid
FHAsx x-component of the finite helical axis solid
FHAsy y-component of the finite helical axis solid
FHAsz z-component of the finite helical axis solid
FHAtd solid
FHAwm solid
FHAwx x-component of angular rotation vector around finite helical axis solid
FHAwy y-component of angular rotation vector around finite helical axis solid
FHAwz z-component of angular rotation vector around finite helical axis solid
fiber_stretch The element's fiber stretch, averaged over integration points. solid
fiber_x The x-component of the element's fiber vector solid
fiber_y The y-component of the element's fiber vector solid
fiber_z The z-component of the element's fiber vector solid
fJ fluid volume ratio fluid
fmxs maximum shear of fluid Cauchy stress fluid
fp fluid pressure fluid
fs1 1st principal fluid Cauchy stress fluid
fs2 2nd principal fluid Cauchy stress fluid
fs3 3rd principal fluid Cauchy stress fluid
fsp fluid stress power fluid
fsxx xx-component of fluid Cauchy stress fluid
fsxy xy-component of fluid Cauchy stress fluid
fsxz xz-component of fluid Cauchy stress fluid
fsyy yy-component of fluid Cauchy stress fluid
fsyz yz-component of fluid Cauchy stress fluid
fszz zz-component of fluid Cauchy stress fluid
Ft_xx The xx component of the total deformation gradient of a prestrain material solid
Ft_xy The xy component of the total deformation gradient of a prestrain material solid
Ft_xz The xz component of the total deformation gradient of a prestrain material solid
Ft_yx The yx component of the total deformation gradient of a prestrain material solid
Ft_yy The yy component of the total deformation gradient of a prestrain material solid
Ft_yz The yz component of the total deformation gradient of a prestrain material solid
Ft_zx The zx component of the total deformation gradient of a prestrain material solid
Ft_zy The zy component of the total deformation gradient of a prestrain material solid
Ft_zz The zz component of the total deformation gradient of a prestrain material solid
fvx x-component of fluid velocity fluid
fvy y-component of fluid velocity fluid
fvz z-component of fluid velocity fluid
fwx x-component of fluid vorticity fluid
fwy y-component of fluid vorticity fluid
fwz z-component of fluid vorticity fluid
fx x-coordinate of element centroid position fluid
Fx x-component of the rigid body reaction force solid
Fxx xx-component of the deformation gradient solid
Fxy xy-component of the deformation gradient solid
Fxz xz-component of the deformation gradient solid
fy y-coordinate of element centroid position fluid
Fy y-component of the rigid body reaction force solid
Fyx yx-component of the deformation gradient solid
Fyy yy-component of the deformation gradient solid
Fyz yz-component of the deformation gradient solid
fz z--coordinate of element centroid position fluid
Fz z-component of the rigid body reaction force solid
Fzx xz-component of the deformation gradient solid
Fzy zy-component of the deformation gradient solid
Fzz zz-component of the deformation gradient solid
h1 first eigenvalue of left Hencky strain solid
H1 first eigenvalue of right Hencky strain solid
h2 second eigenvalue of left Hencky strain solid
H2 second eigenvalue of right Hencky strain solid
h3 third eigenvalue of left Hencky strain solid
H3 third eigenvalue of right Hencky strain solid
hx xx-component of the left Hencky strain solid
Hx xx-component of the right Hencky strain solid
hxy xy-component of the left Hencky strain solid
Hxy xy-component of the right Hencky strain solid
hxz xz-component of the left Hencky strain solid
Hxz xz-component of the right Hencky strain solid
hy yy-component of the left Hencky strain solid
Hy yy-component of the right Hencky strain solid
hyz yz-component of the rileft Hencky strain solid
Hyz yz-component of the right Hencky strain solid
hz zz-component of the left Hencky strain solid
Hz zz-component of the right Hencky strain solid
Iex The x-component of the element current density in a multiphasic material multiphasic
Iey The y-component of the element current density in a multiphasic material multiphasic
Iez The z-component of the element current density in a multiphasic material multiphasic
IHAsx x-component of the instantaneous helical axis solid
IHAsy y-component of the instantaneous helical axis solid
IHAsz z-component of the instantaneous helical axis solid
IHAtd solid
IHAwm solid
IHAwx x-component of angular rotation vector around instantaneous helical axis solid
IHAwy y-component of angular rotation vector around instantaneous helical axis solid
IHAwz z-component of angular rotation vector around instantaneous helical axis solid
integrate core
J relative volume (determinant of deformation gradient) solid
j1x The x-component of the flux of solute with index 1 in a multiphasic material solute
j1y The y-component of the flux of solute with index 1 in a multiphasic material solute
j1z The z-component of the flux of solute with index 1 in a multiphasic material solute
j2x The x-component of the flux of solute with index 2 in a multiphasic material solute
j2y The y-component of the flux of solute with index 2 in a multiphasic material solute
j2z The z-component of the flux of solute with index 2 in a multiphasic material solute
j3x The x-component of the flux of solute with index 3 in a multiphasic material solute
j3y The y-component of the flux of solute with index 3 in a multiphasic material solute
j3z The z-component of the flux of solute with index 3 in a multiphasic material solute
j4x The x-component of the flux of solute with index 4 in a multiphasic material solute
j4y The y-component of the flux of solute with index 4 in a multiphasic material solute
j4z The z-component of the flux of solute with index 4 in a multiphasic material solute
j5x The x-component of the flux of solute with index 5 in a multiphasic material solute
j5y The y-component of the flux of solute with index 5 in a multiphasic material solute
j5z The z-component of the flux of solute with index 5 in a multiphasic material solute
j6x The x-component of the flux of solute with index 6 in a multiphasic material solute
j6y The y-component of the flux of solute with index 6 in a multiphasic material solute
j6z The z-component of the flux of solute with index 6 in a multiphasic material solute
j7x The x-component of the flux of solute with index 7 in a multiphasic material solute
j7y The y-component of the flux of solute with index 7 in a multiphasic material solute
j7z The z-component of the flux of solute with index 7 in a multiphasic material solute
j8x The x-component of the flux of solute with index 8 in a multiphasic material solute
j8y The y-component of the flux of solute with index 8 in a multiphasic material solute
j8z The z-component of the flux of solute with index 8 in a multiphasic material solute
jx x-component of flux of solute in biphasic-solute material solute
jy y-component of flux of solute in biphasic-solute material solute
jz z-component of flux of solute in biphasic-solute material solute
KE kinetic energy solid
Kpxx xx-component of the permeability tensor. biphasic
Kpxy xy-component of the permeability tensor. biphasic
Kpxz xz-component of the permeability tensor. biphasic
Kpyy yy-component of the permeability tensor. biphasic
Kpyz yz-component of the permeability tensor. biphasic
Kpzz zz-component of the permeability tensor. biphasic
max contact gap The maximum contact gap value evaluated over the entire surface. solid
mixture_stress[0].xx The xx component of the mixture stress tensor for solid component 0 in a solid mixture material. solid
mixture_stress[0].xy The xy component of the mixture stress tensor for solid component 0 in a solid mixture material. solid
mixture_stress[0].xz The xz component of the mixture stress tensor for solid component 0 in a solid mixture material. solid
mixture_stress[0].yy The yy component of the mixture stress tensor for solid component 0 in a solid mixture material. solid
mixture_stress[0].yz The yz component of the mixture stress tensor for solid component 0 in a solid mixture material. solid
mixture_stress[0].zz The zz component of the mixture stress tensor for solid component 0 in a solid mixture material. solid
mixture_stress[1].xx The xx component of the mixture stress tensor for solid component 1 in a solid mixture material. solid
mixture_stress[1].xy The xy component of the mixture stress tensor for solid component 1 in a solid mixture material. solid
mixture_stress[1].xz The xz component of the mixture stress tensor for solid component 1 in a solid mixture material. solid
mixture_stress[1].yy The yy component of the mixture stress tensor for solid component 1 in a solid mixture material. solid
mixture_stress[1].yz The yz component of the mixture stress tensor for solid component 1 in a solid mixture material. solid
mixture_stress[1].zz The zz component of the mixture stress tensor for solid component 1 in a solid mixture material. solid
mixture_stress[2].xx The xx component of the mixture stress tensor for solid component 2 in a solid mixture material. solid
mixture_stress[2].xy The xy component of the mixture stress tensor for solid component 2 in a solid mixture material. solid
mixture_stress[2].xz The xz component of the mixture stress tensor for solid component 2 in a solid mixture material. solid
mixture_stress[2].yy The yy component of the mixture stress tensor for solid component 2 in a solid mixture material. solid
mixture_stress[2].yz The yz component of the mixture stress tensor for solid component 2 in a solid mixture material. solid
mixture_stress[2].zz The zz component of the mixture stress tensor for solid component 2 in a solid mixture material. solid
Mx x-component of the rigid body reaction torque solid
My y-component of the rigid body reaction torque solid
Mz z-component of the rigid body reaction torque solid
nfvx x-component of fluid velocity fluid
nfvy y-component of fluid velocity fluid
nfvz z-component of fluid velocity fluid
normalized internal energy The integral over space and time of the internal energy normalized by the volume of the domain solid
omx x-component of angular velocity solid
omy y-component of angular velocity solid
omz z-component of angular velocity solid
ops the octahedral plastic strain solid
p actual fluid pressure biphasic
pct Percentile of another log variable over domain core
pe effective nodal fluid pressure. solute
porosity the porosity calculated from \(1-\phi_r/J\) where \(\phi_r\) is the referential solid volume fraction. biphasic
psi the element-averaged electric potential of an element in a multiphasic material. multiphasic
Pxx The xx component of the PK1 stress solid
Pxy The xy component of the PK1 stress solid
Pxz The xz component of the PK1 stress solid
Pyx The yx component of the PK1 stress solid
Pyy The yy component of the PK1 stress solid
Pyz The yz component of the PK1 stress solid
Pzx The zx component of the PK1 stress solid
Pzy The zy component of the PK1 stress solid
Pzz The zz component of the PK1 stress solid
qw w-component of rotation quaternion solid
qx x-component of rotation quaternion solid
qy y-component of rotation quaternion solid
qz z-component of rotation quaternion solid
R11 11-component of the rigid body's rotation matrix solid
R12 12-component of the rigid body's rotation matrix solid
R13 13-component of the rigid body's rotation matrix solid
R21 21-component of the rigid body's rotation matrix solid
R22 22-component of the rigid body's rotation matrix solid
R23 23-component of the rigid body's rotation matrix solid
R31 31-component of the rigid body's rotation matrix solid
R32 32-component of the rigid body's rotation matrix solid
R33 33-component of the rigid body's rotation matrix solid
rcFHAsx solid
rcFHAsy solid
rcFHAsz solid
rcFHAtd solid
rcFHAwm solid
rcFHAwx solid
rcFHAwy solid
rcFHAwz solid
RCFx x-component of rigid connector force solid
RCFy y-component of rigid connector force solid
RCFz z-component of rigid connector force solid
rcIHAsx solid
rcIHAsy solid
rcIHAsz solid
rcIHAtd solid
rcIHAwm solid
rcIHAwx solid
rcIHAwy solid
rcIHAwz solid
RCMx x-component of rigid connector moment solid
RCMy y-component of rigid connector moment solid
RCMz z-component of rigid connector moment solid
RCthx x-component of rigid connector rotation solid
RCthy y-component of rigid connector rotation solid
RCthz z-component of rigid connector rotation solid
RCx x-component of rigid connector translation solid
RCy y-component of rigid connector translation solid
RCz z-component of rigid connector translation solid
Rx x-coordinate of nodal reaction force solid
Ry y-coordinate of nodal reaction force solid
Rz z-coordinate of nodal reaction force solid
s1 first eigenvalue of Cauchy stress tensor solid
s1x The x-component of the 1st Eigen vector of the Cauchy stress solid
s1y The y-component of the 1st Eigen vector of the Cauchy stress solid
s1z The z-component of the 1st Eigen vector of the Cauchy stress solid
s2 second eigenvalue of Cauchy stress tensor solid
s2x The x-component of the 2nd Eigen vector of the Cauchy stress solid
s2y The y-component of the 2nd Eigen vector of the Cauchy stress solid
s2z The z-component of the 2nd Eigen vector of the Cauchy stress solid
s3 third eigenvalue of Cauchy stress tensor solid
s3x The x-component of the 3rd Eigen vector of the Cauchy stress solid
s3y The y-component of the 3rd Eigen vector of the Cauchy stress solid
s3z The z-component of the 3rd Eigen vector of the Cauchy stress solid
sbm1 the element-averaged concentration of solid-bound molecule with index 1 in a multiphasic material. multiphasic
sbm1_integral The integral of sbm 1 concentration over the multiphasic material domain. multiphasic
sbm1_referential_apparent_density The referential apparent density of solid-bound molecule with index 1 in a multiphasic material. multiphasic
sbm2 the element-averaged concentration of solid-bound molecule with index 2 in a multiphasic material. multiphasic
sbm2_integral The integral of sbm 2 concentration over the multiphasic material domain. multiphasic
sbm2_referential_apparent_density The referential apparent density of solid-bound molecule with index 2 in a multiphasic material. multiphasic
sbm3 the element-averaged concentration of solid-bound molecule with index 3 in a multiphasic material. multiphasic
sbm3_integral The integral of sbm 3 concentration over the multiphasic material domain. multiphasic
sbm3_referential_apparent_density The referential apparent density of solid-bound molecule with index 3 in a multiphasic material. multiphasic
sbm4 the element-averaged concentration of solid-bound molecule with index 4 in a multiphasic material. multiphasic
sbm4_integral The integral of sbm 4 concentration over the multiphasic material domain. multiphasic
sbm4_referential_apparent_density The referential apparent density of solid-bound molecule with index 4 in a multiphasic material. multiphasic
sbm5 the element-averaged concentration of solid-bound molecule with index 5 in a multiphasic material. multiphasic
sbm5_integral The integral of sbm 5 concentration over the multiphasic material domain. multiphasic
sbm5_referential_apparent_density The referential apparent density of solid-bound molecule with index 5 in a multiphasic material. multiphasic
sbm6 the element-averaged concentration of solid-bound molecule with index 6 in a multiphasic material. multiphasic
sbm6_integral The integral of sbm 6 concentration over the multiphasic material domain. multiphasic
sbm6_referential_apparent_density The referential apparent density of solid-bound molecule with index 6 in a multiphasic material. multiphasic
sbm7 the element-averaged concentration of solid-bound molecule with index 7 in a multiphasic material. multiphasic
sbm7_integral The integral of sbm 7 concentration over the multiphasic material domain. multiphasic
sbm7_referential_apparent_density The referential apparent density of solid-bound molecule with index 7 in a multiphasic material. multiphasic
sbm8 the element-averaged concentration of solid-bound molecule with index 8 in a multiphasic material. multiphasic
sbm8_integral The integral of sbm 8 concentration over the multiphasic material domain. multiphasic
sbm8_referential_apparent_density The referential apparent density of solid-bound molecule with index 8 in a multiphasic material. multiphasic
sed strain energy density solid
solution_norm The L2 norm of the solution vector core
sx xx-component of the Cauchy stress solid
Sx The xx-component of the PK2 stress solid
sxy xy-component of the Cauchy stress solid
Sxy The xy-component of the PK2 stress solid
sxz xz-component of the Cauchy stress solid
Sxz The xz-component of the PK2 stress solid
sy yy-component of the Cauchy stress solid
Sy The yy-component of the PK2 stress solid
syz yz-component of the Cauchy stress solid
Syz The yz-component of the PK2 stress solid
sz zz-component of the Cauchy stress solid
Sz The zz-component of the PK2 stress solid
thx x-component of rotation pseudo-vector solid
thy y-component of rotation pseudo-vector solid
thz z-component of rotation pseudo-vector solid
total energy the total energy (elastic energy + kinetic) integrated over a domain. solid
U1 first eigenvalue of right stretch tensor solid
U2 second eigenvalue of right stretch tensor solid
U3 third eigenvalue of right stretch tensor solid
ux x-coordinate of nodal displacement solid
Ux xx-component of the right stretch tensor solid
Uxy xy-component of the right stretch tensor solid
Uxz xz-component of the right stretch tensor solid
uy y-coordinate of nodal displacement solid
Uy yy-component of the right stretch tensor solid
Uyz yz-component of the right stretch tensor solid
uz z-coordinate of nodal displacement solid
Uz zz-component of the right stretch tensor solid
V the current volume of an element core
V1 first eigenvalue of left stretch tensor solid
V2 second eigenvalue of left stretch tensor solid
V3 third eigenvalue of left stretch tensor solid
volume the volume inside a constraining surface. core
volume change the change in volume inside a constraining surface. core
volume pressure The pressure inside the constrained volume of a volume constraint. solid
vx x-component of center of mass velocity solid
Vx xx-component of the left stretch tensor solid
Vxy xy-component of the left stretch tensor solid
Vxz xz-component of the left stretch tensor solid
vy y-component of center of mass velocity solid
Vy yy-component of the left stretch tensor solid
Vyz yz-component of the left stretch tensor solid
vz z-component of center of mass velocity solid
Vz zz-component of the left stretch tensor solid
wf fraction of fatigued bonds solid
wi fraction of intact bonds solid
wx x-component of fluid flux biphasic
wy y-component of fluid flux biphasic
wz z-component of fluid flux biphasic
x x-coordinate of center of mass position solid
y y-coordinate of center of mass position solid
z z-coordinate of center of mass position solid