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Nomenclature
δ 0
Deflection at finale fracture (mm)
a 0
Notch depth of specimen (mm)
V 0
Speeds of striker bar
t
Time (µs)
ε i (t)
Incident strain
ε r (t)
Reflected strain
ε t (t)
Transmitted strain
σ s (t)
Dynamic stress of the specimen (MPa)
ε s (t)
Dynamic strain of the specimen
˙
ε s (t)
Strain rate of the specimen (s
−1 )
E b
Elastic modulus of the bars (GPa)
A 0
Cross-sectional area of the bars (mm
2 )
C 0
Elastic wave velocity of the bars (m/s)
σ t
Transmitted stress on the specimen (MPa)
σ i
Incident stress on the specimen (MPa)
σ r
Reflected stress on the specimen (MPa)
˙
ε
Strain rate (s
−1 )
˙
ε ts
Static strain rate (s
−1 )
A f
Coefficient
B f
Coefficient
C f
Coefficient
˙
ε TR
Transition strain rate (s
−1 )
W
Toughness of a material (N m)
σ
Stress (MPa)
ε
Strain
W p
Peak dynamic toughness (N m)
W u
Ultimate dynamic toughness (N m)
E 0
Elastic constant
λ
Elastic constant
η
Time variable
E 1
Elastic modulus of the low-frequency Maxwell element (GPa)
θ 1
Relaxation time of the low-frequency Maxwell element (s)
E 2
Elastic modulus of the high-frequency Maxwell element (GPa)
θ 2
Relaxation time of the high-frequency Maxwell element (s)
σ M
Modified stress (MPa)
k
Bearing capacity of the steel fibers in the specimen damage zone
D
Damage factor
m d
Damage evolution coefficient
a d
Damage evolution coefficient
ε th
Ultimate elastic strain
ε u
Peak strain
u
Particle displacement (m)
x
Longitudinal coordinate (m)
c
Elastic wave velocity of the specimen (m/s)
σ d
Dynamic spalling strength (MPa)