Fracturing Behavior Study of Three-Flawed Specimens by Uniaxial Compression and 3D Digital Image Correlation: Sensitivity to Brittleness

Zhou, Xiaoping; Wang, Yunteng; Zhang, Jian‐Zhi; Liu, Fei-Nan

doi:10.1007/s00603-018-1600-4

Cited by 125 publications

(39 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Crack coalescence observed in previous studies (see Figure 13) [64][65][66] were reproduced in this study, and no new crack coalescence types appeared in the tested sandstone specimens. Compared with the low-strength rock-like specimen comprising sand, barite, resin and alcohol by Zhou et al, 67 the present study demonstrated that the crack coalescence between flaws and transformed from noncoalescence to indirect coalescence with the increase in flaw angle, indicating that flaw inclination was a key factor affecting the crack coalescence patterns. Compared with the low-strength rock-like specimen comprising barite, sand, plaster and water by Wong et al 68 and the low-strength gypsum specimen by Xu and Li, 61 a direct shear crack coalescence was not observed in the present study, indicating that the crack coalescence behaviour was affected by the rock type.…”

Section: Effect Of Flaw Inclination On Mechanical Properties Of Sancontrasting

confidence: 47%

“…Specifically, the flaw angles were fixed at 30 or 45 , which were relatively low. 14,67,69 However, crack coalescence types III and VI were not discovered at the relatively low angles without thermal treatment, but they occurred at the relatively high flaw angles after thermal treatments. Hence, the present experimental results of three-flawed specimens provided some insights into the crack coalescence behaviour of fractured rocks.…”

Section: Effect Of Flaw Inclination On Mechanical Properties Of Sanmentioning

confidence: 99%

See 1 more Smart Citation

Experimental study on fracture behaviour of three‐flawed sandstone specimens after high‐temperature treatments

Huang

Yang

Dong

2020

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

The crack coalescence of rocks significantly affects the stability of rock engineering, and extensive studies have been performed on preflawed rock specimens without thermal treatment. However, the fracturing behaviour of preflawed specimens after thermal treatment has not been investigated comprehensively. In this study, three‐flawed sandstone specimens with different flaw inclinations after high‐temperature treatments were tested under uniaxial compression. Photographic, acoustic emission and digital image correlation techniques were used to investigate the crack initiation, propagation and coalescence behaviour. Experimental results show that the peak strength, elastic modulus and peak strain of the three‐flawed specimens were lower than those of intact specimens and that they gradually recovered with increasing flaw angle. The peak strength and elastic modulus first increased and then decreased, whereas the peak strain increased with temperature. Noncoalescence, indirect coalescence and direct coalescence were three patterns observed between the two adjacent pre‐existing flaws. Finally, the mechanism of high temperature in alteration of the mechanical properties of sandstone was revealed through microobservations.

show abstract

Section: Effect Of Flaw Inclination On Mechanical Properties Of Sancontrasting

confidence: 47%

Section: Effect Of Flaw Inclination On Mechanical Properties Of Sanmentioning

confidence: 99%

Experimental study on fracture behaviour of three‐flawed sandstone specimens after high‐temperature treatments

Huang

Yang

Dong

2020

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

show abstract

“…Miao et al [29] investigated the crack evolution in sandstone containing a filled flaw through the strain fields of the specimen. Zhou et al [30] applied the DIC technique to analyze the fracturing characteristics of rock-like specimens with three joints. Zhu et al [31] carried out uniaxial loading tests on sandstone specimens with two inclusions and obtained the law of crack propagation around the hole.…”

Section: Introductionmentioning

confidence: 99%

Mechanical behavior around double circular openings in a jointed rock mass under uniaxial compression

Lin

Cao

et al. 2020

Archiv.Civ.Mech.Eng

View full text Add to dashboard Cite

To better understand the mechanical behavior in a jointed rock mass, a series of uniaxial compression tests were conducted on non-persistently jointed rock specimens with double circular holes. Acoustic emission (AE) and digital image correlation (DIC) techniques were applied to capture micro-crack events and real-time strain field evolution in the specimens. The results indicate that the existence of non-persistent joints has a significant influence on the strength characteristics of the specimens. Specifically, peak strength decreases at first and reaches a minimum at 30° then increases with increase in the joint dip angle. DIC technology has successfully monitored the development of surface strain fields. The fracture evolution process is comprehensively understood. Every sudden change in a strain field is usually accompanied by apparent AE events and stress-strain curves take the form of oscillations. The crack coalescence modes among joints can be summarized as six types and the crack coalescence patterns around holes and joints can be divided into three categories. These results are helpful to understanding further the mechanical properties and fracture mechanism of openings in non-persistently jointed rock masses.

show abstract

“…Traditionally, the mechanical properties of intact coal and rock were mainly measured by standard centimeter-scale tests, mainly including uniaxial compression, triaxial compression, tension, bending, cutting, and polyaxial tests [18][19][20][21][22]. However, for soft and broken coal and rock obtained from deep underground coal mines, this experimental method is not feasible due to the impossibility of obtaining intact standard samples.…”

Section: Introductionmentioning

confidence: 99%

Mechanical and Heterogeneous Properties of Coal and Rock Quantified and Mapped at the Microscale

Sun

Zhang

et al. 2020

Applied Sciences

View full text Add to dashboard Cite

Due to the impossibility of obtaining intact standard experimental samples, it is difficult to test the mechanical properties of soft and broken coal and rock obtained from deep coal mines. So, an advanced experimental technology based on a small sample volume, nanoindentation technology, was introduced and used to measure the mechanical parameters of them. By using the averaging method, the hardness of shale, mudstone and coal are 1191.90 MPa, 674.95 MPa and 424.30 MPa, respectively; their elastic moduli are 20.39 GPa, 11.72 GPa and 5.47 GPa; and their fracture toughness were 1.66 MPa·m0.5, 1.28 MPa·m0.5 and 0.77 MPa·m0.5. These three mechanical parameters were used to quantify and map the heterogeneous properties of coal and rock for convenience and accuracy. For example, the inter quartile range (IQR) of the hardness of shale, mudstone, and coal are 1502.10 MPa, 1016.20 MPa and 54.64 MPa, respectively, meaning that coal has the best homogeneity among them. Nanoindentation technology provides researchers with a convenient method to conduct mechanical experiments at the microscale.

show abstract

Fracturing Behavior Study of Three-Flawed Specimens by Uniaxial Compression and 3D Digital Image Correlation: Sensitivity to Brittleness

Cited by 125 publications

References 40 publications

Experimental study on fracture behaviour of three‐flawed sandstone specimens after high‐temperature treatments

Experimental study on fracture behaviour of three‐flawed sandstone specimens after high‐temperature treatments

Mechanical behavior around double circular openings in a jointed rock mass under uniaxial compression

Mechanical and Heterogeneous Properties of Coal and Rock Quantified and Mapped at the Microscale

Contact Info

Product

Resources

About