scholarly journals Numerical modeling of wing crack propagation accounting for fracture contact mechanics

2020 ◽  
Vol 204-205 ◽  
pp. 233-247
Author(s):  
Hau Dang-Trung ◽  
Eirik Keilegavlen ◽  
Inga Berre
Keyword(s):  
Numerical Modeling ◽  
Crack Propagation ◽  
Contact Mechanics ◽  
Wing Crack

scholarly journals Progressive Failure and Acoustic Emission Characteristics of Red Sandstone with Different Geometry Parallel Cracks under Uniaxial Compression Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xizhen Sun ◽  
Fanbao Meng ◽  
Ce Zhang ◽  
Xucai Zhan ◽  
He Jiang
Keyword(s):  
Acoustic Emission ◽  
Crack Initiation ◽  
Crack Propagation ◽  
Geometric Distribution ◽  
Progressive Failure ◽  
Fractured Rock ◽  
Propagation Mode ◽  
Wing Crack ◽  
Red Sandstone ◽  
Parallel Cracks

The geometric distribution of initial damages has a great influence on the strength and progressive failure characteristics of the fractured rock mass. Initial damages of the fractured rock were simplified as parallel cracks in different geometric distributions, and then, the progressive failure and acoustic emission (AE) characteristics of specimens under the uniaxial compression loading were analyzed. The red sandstone (brittle materials) specimens with the parallel preexisting cracks by water jet were used in the tests. The energy peak and stress attenuation induced by the energy release of crack initiation were intuitively observed in the test process. Besides, three modes of rock bridge coalescence were obtained, and wing crack was the main crack propagation mode. The wing crack and other cracks were initiated in different loading stages, which were closely related to the energy level of crack initiation. The propagation of wing crack (stable crack) consumed a large amount of energy, and then, the propagation of shear crack, secondary crack, and anti-wing crack (unstable crack) was inhibited. The relationship between the crack propagation mode and the geometric distribution of existing cracks in the specimen was revealed. Meanwhile, the strength characteristic and failure mode of fractured rock with the different geometric distributions of preexisting crack were also investigated. The energy evolution characteristics and crack propagation were also analyzed by numerical modeling (PFC2D).

scholarly journals Investigation of the Blast-Induced Crack Propagation Behavior in a Material Containing an Unfilled Joint

2020 ◽  
Vol 10 (13) ◽  
pp. 4419
Author(s):  
Peng Xu ◽  
Renshu Yang ◽  
Yang Guo ◽  
Zhicheng Guo
Keyword(s):  
Shear Stress ◽  
Stress Concentration ◽  
Crack Propagation ◽  
Wing Crack ◽  
Reflected Wave ◽  
Propagation Behavior ◽  
Dilatational Wave ◽  
Propagating Crack ◽  
Vertical Joint ◽  
Crack Propagation Behavior

This study uses a dynamic caustic technique to study the crack propagation in a medium containing an unfilled joint under blasting. The results show that for the medium containing a vertical unfilled joint, the reflected dilatational wave from the joint tends to suppress both the K I d and the velocity of the opposite propagating crack. However, for the medium containing an oblique joint, the reflected wave from the joint increases K II d , and induces the opposite propagating crack deflect from its original path. Compared with the medium with a vertical joint, the wing cracks are more easy to initiate at the oblique joint where a significant stress concentration is formed under the diffraction of the blast wave. Combined with numerical results, it is found that the wing crack deflects in the clockwise direction when the shear stress was negative, and it turns to counterclockwise when the shear stress was positive.

NUMERICAL MODELING OF MORPHOLOGICAL CHANGES OF THE FRACTURE PROPAGATION IN THE QUENCHED GLASS PLATE

1994 ◽  
Vol 08 (21n22) ◽  
pp. 1335-1341 ◽  
Author(s):  
Y.-H. TAGUCHI
Keyword(s):  
Numerical Modeling ◽  
Crack Propagation ◽  
Morphological Changes ◽  
Glass Plate ◽  
Fracture Propagation ◽  
Morphological Transitions ◽  
Quenched Glass ◽  
First Time

A model for crack propagation is proposed that reproduces, for the first time, the morphological transitions of cracks in the quenched glass plate recently observed by Yuse and Sano [Nature362, 329 (1993)].

Numerical modeling crack propagation of sheet metal forming based on stress state parameters using XFEM method

2013 ◽  
Vol 69 ◽  
pp. 311-326 ◽  
Author(s):  
Fengmei Xue ◽  
Fuguo Li ◽  
Jiang Li ◽  
Min He ◽  
Zhanwei Yuan ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Stress State ◽  
Crack Propagation ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming

Crack Growth Mechanisms from 3-D Surface Flaw with Varied Dipping Angle under Uniaxial Compression

2007 ◽  
Vol 353-358 ◽  
pp. 2353-2356 ◽  
Author(s):  
Y.S.H. Guo ◽  
R.H.C. Wong ◽  
K.T. Chau ◽  
Wei Shen Zhu ◽  
Shu Cai Li
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Crack Growth ◽  
Uniaxial Compression ◽  
Axial Loading ◽  
Growth Direction ◽  
Surface Flaw ◽  
Growth Mechanisms ◽  
Wing Crack ◽  
Ae Energy

A number of instability problems in rock engineering projects are caused by crack propagation. However, crack growth mechanisms from 3-dimentional flaw are not fully understood, in particular for 3-D flaw case with varied dipping angle. This study focuses on 3-D surface flaw using real rock specimens containing a flaw with varied inclination angle α from axial loading and dipping angle γ from specimen surface under uniaxial compression. Acoustic emission technique was used for tracing the initiation and growth of micro-cracks inside of specimen. It was found that crack growth process is affected by the dipping angle γ of the 3-D flaw. When dipping angle γ ≠ 90º, the thickness of rock above the flaw plane is thinner than that of below the flaw plane. As a result, compressive crack and wing crack initiated easily from the thinner flaw tips. And, the normalized stress for crack initiation σi /σc, AE events and the AE energy for crack growth decreases with the dipping angle γ. However, for γ = 90º, the thickness of rock above and below of the flaw tips is the same, it was observed that anti-wing crack (crack growth direction opposite to wing crack) initiated first at a certain place away from the flaw tips, then wing crack and compressive crack emerged at the late stage. For this case, the stress σi /σc, AE events and the AE energy for crack initiation and propagation are at a high value. Thus, for rock mass contains flaws geometry with small dipping angle, some problems of crack propagation may be induced easily during excavation.

Numerical Studies of End Effect on Crack Propagation Behavior of Brittle Specimen Containing Pre-Existing Crack under Uniaxial Compression

2007 ◽  
Vol 353-358 ◽  
pp. 1049-1052
Author(s):  
Ming Li Huang ◽  
Shan Yong Wang ◽  
Wei Lu ◽  
Wan Cheng Zhu
Keyword(s):  
Crack Propagation ◽  
Uniaxial Compression ◽  
Process Analysis ◽  
Failure Process ◽  
End Effect ◽  
Wing Crack ◽  
Propagation Length ◽  
Propagation Behavior ◽  
Numerical Studies ◽  
Crack Propagation Process

In this paper, a Material Failure Process Analysis code (MFPA2D) was employed to investigate the interaction of end effect zone of specimen with the wing crack propagation inside the brittle specimen containing pre-existing flaws under uniaxial compression comparing with the experimental results. The numerical results show that the shorter the distance between the pre-existing flaw and the specimen's end , the slower the crack propagation process and the shorter wing propagation length is , and vice versa. In addition, the end effect zone was also influenced by the wing crack propagation.

scholarly journals Micromechanics of wing crack propagation for different flaw properties

2016 ◽  
Vol 153 ◽  
pp. 378-398 ◽  
Author(s):  
J. Duriez ◽  
L. Scholtès ◽  
F.-V. Donzé
Keyword(s):  
Crack Propagation ◽  
Wing Crack
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