B	strain matrix
$C_t^{max},C_n^{max}$	the maximum cohesive strength for mode I and mode II
E	Young’s modulus
$E^{\prime }$	normal or inplane stiffness
$f^{in}$	Internal force of element
$G_C$	the energy release rate of type I or type II cracks
$G_I$	the critical energy release rate for mode I
$I_1$, $I_2$, and $I_3$	invariants related to R
J	Jacobian matrix
k	stiffness
$Q_{MAX}$	the tensile strength T of type I crack or shear strength S of type II crack
$R_{n+1/2}$	transformational matrix
$Ri$	the orthogonal transformation matrix
T	cohesive force
u	the ultimate displacement in the normal or tangential direction
V	element field
v	Poisson’s ratio
$XMU$	the mixed-mode failure criterion index, where XMU is less than zero
$x_n$ and $x_{n+1}$	the spatial coordinates of the two configurations in global Cartesian coordinates,
	which are represented using local coordinates
R	the right Cauchy–Green strain tensor