CAO Fu, YANG Li-ping, LI Lian, et al. Research on whole dynamical fracture process of rock using single cleavage drilled compression(SCDC) specimen[J]. 2017, 38(6): 1573-1582.
CAO Fu, YANG Li-ping, LI Lian, et al. Research on whole dynamical fracture process of rock using single cleavage drilled compression(SCDC) specimen[J]. 2017, 38(6): 1573-1582.DOI: 10.16285/j.rsm.2017.06.005.
Research on whole dynamical fracture process of rock using single cleavage drilled compression(SCDC) specimen
Dynamic experiments were conducted on single cleavage drilled compression(SCDC) specimens of sandstone using large-diameter split Hopkinson pressure bar to obtain the whole dynamic fracturing process of Mode-I crack.A crack propagation gauge was used to measure the key moments of dynamic initiation
propagation
arrest and re-initiation
respectively.A fractal model of crack extension was applied to analyze the propagation speed of a tortuous crack.Finally
we determined the dynamic initiation toughness
dynamic propagation toughness
dynamic arrest toughness
and dynamic re-initiation toughness using the experimental-numerical-analytical method.The results demonstrate that the crack propagation path is torturous in the process of crack propagation.For this irregular curve path
the value of the universal function
which was characterized by the crack propagation velocity
was smaller than that with a straight path.It is found that the dynamic propagation toughness obtained by the fractal model was close to its real value.The dynamic initiation toughness was greater than the dynamic arrest toughness
and the dynamic initiation toughness was slightly greater than the dynamic re-initiation toughness.The reason probably was that the naturally formed crack at the second re-initiation was sharp
while the artificial notch for the first dynamic initiation was blunt at a certain degree.