$d{F}_{t,j}\left({\varphi }_j\left(z\right)\right)$	The differential tangential cutting force (N)
$d{F}_{r,j}\left({\varphi }_j\left(z\right)\right)$	The differential radial cutting force (N)
$d{F}_{a,j}\left({\varphi }_j\left(z\right)\right)$	The differential axial cutting force (N)
$K_{tc}$	Tangential shearing force coefficient (N/mm2)
$K_{rc}$	Radial shearing force coefficient (N/mm2)
$K_{ac}$	Axial shearing force coefficient (N/mm2)
$K_{te}$	Tangential edge force coefficient (N/mm)
$K_{re}$	Radial edge force coefficient (N/mm)
$K_{ae}$	Axial edge force coefficient (N/mm)
$h_j\left({\varphi }_j\left(z\right)\right)$	The instantaneous chip thickness at immersion angle (mm)
$dS\left({\varphi }_j\left(z\right)\right)$	The instantaneous edge length of the cutting segment (mm)
$db$	The instantaneous chip width (mm)
$F_f\left(\varphi \right)$	The cutting force in feed direction (N)
$F_n\left(\varphi \right)$	The cutting force in normal direction (N)
$F_z\left(\varphi \right)$	The cutting force in axial direction (N)
$\overline{F_f}$	The average cutting force in the feed direction (N)
$\overline{F_n}$	The average cutting force in the normal direction (N)
$\overline{F_z}$	The average cutting force in the axial direction (N)
$\overline{F_{fc}}$, $\overline{F_{fe}}$	The components of linear model force in the feed direction (N)
$\overline{F_{nc}}$, $\overline{F_{ne}}$	The components of linear model force in the normal direction (N)
$\overline{F_{zc}}$, $\overline{F_{ze}}$	The components of linear model force in the axial direction (N)
$\sigma \left({\epsilon }^p,\dot{\epsilon },T\right)$	Workpiece material flow stress
$g\left({\epsilon }^p\right)$	Strain enhancement function
$\Gamma (\dot{\epsilon })$	Strain rate effect function
$\Theta (T)$	Thermal softening function
$\dot{\epsilon }$	Strain rate
$T$	Temperature
${\sigma }_0$	Initial yield stress
${\epsilon }^p$	Plastic strain
${\epsilon }_0^p$	Reference plastic strain
${\epsilon }_{cut}^p$	Cut-off strain value
$n$	Contingency strengthening index
$\Delta {\epsilon }_i^p$	Instantaneous strain increment
${\epsilon }_{f_i}^p$	Material failure strain
$m_x$, $m_y$	Mass of machine–tool system in the x- and y-directions
$c_x$, $c_y$	Damping of machine–tool system in the x- and y-directions
$k_x$, $k_y$	Stiffness of machine–tool system in the x- and y-directions
$F_{xj}$, $F_{yj}$	Cutting force components acting on the tooth in the x- and y-directions
$v_{j,0}$	Dynamic displacement of the cutter in the previous cycle
$v_j$	Dynamic displacement of the cutter in the current cycle
$g\left({\varphi }_j\right)$	Unit step function
${\Phi }_{xx}\left(i\omega \right)$	Direct transfer function in the x-direction
${\Phi }_{yy}\left(i\omega \right)$	Direct transfer function in the y-direction
${\Phi }_{xy}\left(i\omega \right)$	Cross-transfer function in the x-direction
${\Phi }_{yx}\left(i\omega \right)$	Cross-transfer function in the y-direction
$v_c$	Speed of milling process
$n$	Rotating speed of spindle
$f_z$	Feed per tooth
$a_e$	Radial depth of cut
$a_p$	Axial depth of cut