Jianfeng Yang
Xi'an University of Science and Technology
Rank (linear algebra)Supercritical fluidGeologySupercritical carbon dioxideBrittlenessComposite materialAsphaltPermeability (earth sciences)Geotechnical engineeringMaterials scienceOverburden pressureFractal dimensionBeddingHydraulic fracturingFracture (geology)CoalCohesive zone modelMechanicsFracture mechanicsPetroleum engineeringBendingFluid dynamicsFracture toughness
21Publications
6H-index
195Citations
Publications 17
Newest
#1Leilei Chen (Xinyang Normal University)H-Index: 11
#2Zhongwang Wang (Xinyang Normal University)
Last. Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
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This paper simulates the propagation of hydraulic fractures under constant fluid pressure using the isogeometric analysis based on boundary element methods (BEM) i.e. the so called isogeomtric BEM. Due to the seamless integration between computer aided design (CAD) and numerical analysis, the isogeomtric BEM eliminates the meshing procedure and geometric errors, and explicitly parametrizes the crack propagation path. Graded knot insertion near the crack tip is used to effectively capture the str...
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#1Jianfeng Yang (Xi'an University of Science and Technology)H-Index: 6
#2Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
Last. Vinh Phu Nugyen (Monash University, Clayton campus)
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Abstract The present work studies the Park–Paulino–Roesler (PPR) model, a unified potential-based cohesive zone model (CZM), for mixed mode I/II fractures in different ranked coals, including weakly caking coals, fat coals and anthracite, by using disk-shaped compact tension (DC(T)) tests and punch-through shear (PTS) tests. The PTS experiments showed that with the increase in coal rank, the initial shear stiffness and shear peak loads grow and the maximum tangential crack opening displacement (...
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#1Jianfeng Yang (Xi'an University of Science and Technology)H-Index: 6
#2Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
Last. Li Li (UW: University of Waterloo)H-Index: 4
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Abstract The present paper investigates the effects of CO2-saturation and confining pressures on the fracture toughness of carbon dioxide saturated bituminous coals. Three-point bending experiments were performed with semi-circular coal specimens (SCB) after they were immersed in different CO2 pressures. The experimental results show that the pure modes I and II fracture toughnesses of coal samples gradually decrease with the growth of CO2-saturation pressure. Additionally, the fracture toughnes...
2 CitationsSource
#1Li LiH-Index: 4
#2Weiguo LiangH-Index: 14
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#1Jianfeng Yang (Xi'an University of Science and Technology)H-Index: 6
#2Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
Last. Li Li (UW: University of Waterloo)H-Index: 4
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The present work conducted laboratory experiments of fracturing in fat coals, anthracites, and mudstones. Three different fluids were selected as the fracturing fluids, including water, liquid CO2 (L-CO2), and supercritical CO2 (Sc-CO2). The resulting fracture morphologies and fracture apertures of the coal specimens were investigated using 3D morphological scanning, and the permeabilities of the samples were measured before and after fracturing. The experimental results showed that the breakdow...
3 CitationsSource
#1Jianfeng Yang (TUT: Taiyuan University of Technology)H-Index: 6
#2Li LiH-Index: 4
Last. Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
view all 3 authors...
The influence of water content on mode I fracture toughness (KIc) of mudstones has been studied using semi-circular bend (SCB) specimens subject to three-point bendings. And the mudstone SCB specimens are divided into three types, including Type-A, Type-B and Type-C, corresponding to the three configurations of the bedding planes, including divider direction, arrester direction, and transverse direction, respectively. The test results show that the values of KIc for the three types of specimens ...
2 CitationsSource
#1Liu Zhenghe (TUT: Taiyuan University of Technology)H-Index: 1
#1Zhenghe Liu (TUT: Taiyuan University of Technology)H-Index: 1
Last. Jianfeng Yang (TUT: Taiyuan University of Technology)H-Index: 6
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3 CitationsSource
#1Weiguo Liang (TUT: Taiyuan University of Technology)H-Index: 14
#2Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
Last. Jianfeng Yang (TUT: Taiyuan University of Technology)H-Index: 6
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Hydraulic fracturing is regarded as a promising technology in exploiting unconventional natural gas. Compared to the enormous success achieved in shale-gas exploitation, the application of hydraulic fracturing in coal strata has not matured to a satisfactory level. The main reason is that the models commonly used in hydraulic fracturing in shales fail to reflect the quasi-brittle characteristics of coals. In this Chapter, laboratory experiments were conducted to establish the cohesive zone model...
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#1Jianfeng Yang (TUT: Taiyuan University of Technology)H-Index: 6
#2Li Li (UW: University of Waterloo)H-Index: 4
Last. Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
view all 3 authors...
The effect of water on fracture toughness in various modes of mudstones was investigated using semicircular bend (SCB) specimens exposed to three-point bendings. Natural mudstone specimens are obtained using a special coring method and are then classified into three types (A, B, and C) corresponding to three directions/configurations of bedding planes (divider, arrester, and transverse). The results show that the Type A (divider configuration) specimens possess the largest fracture toughness val...
5 CitationsSource
#1Jianfeng Yang (TUT: Taiyuan University of Technology)H-Index: 6
#2Haojie Lian (TUT: Taiyuan University of Technology)H-Index: 13
Last. Stéphane Bordas (Cardiff University)H-Index: 65
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Abstract The present work develops cohesive zone models (CZM), i.e. cohesion-separation laws, for mode I fractures in different rank coals, including weakly caking coals, gas coals, fat coals, meager-lean coals and anthracite, through disk-shaped compact tension tests. Firstly, the experiments show that with the coal rank rising, the critical crack separation displacements and the degrees of the nonlinearity of the softening function decline gradually. By fitting the experimental data with the f...
13 CitationsSource