List of symbols
a 0	Initial chevron notched crack length
a 1	Final chevron notched crack length
ASTM	American Society of Testing Materials
B	Thickness of CCNBD specimen
B′	Thickness of BD specimen
BD	Brazilian disk
CCNBD	Cracked chevron notched Brazilian disk
d	Average micro-crack density inside FPZ
D	Diameter of CCNBD specimen
D′	Diameter of BD specimen
d 0	Average micro-crack density outside FPZ
DEM	Discrete element method
FPZ	Fracture process zone
GBM	Grain-based model
ISRM	International Society for Rock Mechanics
K I	Tensile stress intensity factor
K IC	Tensile fracture toughness
N	Total micro-crack number
PFC	Particle flow code
P max	Peak applied axial load in CCNBD test
P′max	Peak applied axial load in BD test
R	Radius of CCNBD specimen
r	Polar radius
r c	Radius of circular FPZ
R f	Radius of circular statistical range
R s	Saw radius
u	Geometric constants
v	Geometric constants
XRD	X-ray diffraction
Y * min	Critical dimensionless stress intensity
Greek symbols
α 0	Dimensionless parameter
α 1	Dimensionless parameter
αB	Dimensionless parameter
θ	Polar angle
σ 1	Maximum principal stress
σ 2	Intermediate principal stress
σ t	Tensile strength