Article
Engineering, Mechanical
Sheng-Qi Yang, Wen-Ling Tian, Xiang-Ru Liu, Yan-Hua Huang, Jing Yang
Summary: The presence of pre-existing fissures significantly affects the strength, deformation parameters, and crack propagation in rock specimens, with a greater impact on damage threshold. Coalescence is easier when the ligament angle is parallel to the principal stress, and cracks tend to expand more readily in the width direction.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Chemistry, Multidisciplinary
Pingyang Fan, Jianxin Liu, Wengui Zuo, Min Wang, Daoyong Zhang
Summary: The existence of preexisting fissures in rock masses has a substantial impact on engineering stability. This study investigates the development of specimens with different preexisting fissure types. The findings reveal that the length of the preexisting fissure significantly influences peak strength and coalescence mode.
APPLIED SCIENCES-BASEL
(2022)
Article
Metallurgy & Metallurgical Engineering
Le Hui-lin, Wei Ji-hong, Sun Shao-rui, Wang Wu-chao, Fan Hao-tian
Summary: The mechanical properties and crack behavior of limestone-like samples with two parallel open fissures or cement-infilled fissures were found to be influenced by bridge inclination angle and fissure inclination angle. A new phenomenon of tensile crack closure was observed in samples with small fissure inclination angles. Grouting of cement was shown to transfer stress and reduce stress concentration, affecting peak strength, crack initiation stress, and coalescence type between open fissures and cement-infilled fissures.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2021)
Article
Engineering, Mechanical
Heng Li, Sheng-Qi Yang, Zhen Yang, Xiao-Ping Zhou, Wen-Ling Tian, Su-Sheng Wang
Summary: In this study, the mechanical properties and crack evolution behavior of grey sandstone containing two parallel fissures were evaluated through experimental tests and numerical simulations. The results showed that the peak strength, elastic modulus, and Poisson's ratio of pre-cracked sandstone samples increased with the increase of fissure dip angle. The total energy, dissipated energy, and elastic peak energy of fractured sandstone also increased with the increase of fissure dip angle. Three failure modes were identified for double-fractured sandstone under uniaxial compression: tensile failure, shear failure, and conjugate shear failure. The main control factor for failure gradually changed from rock bridge failure to secondary crack coalescence as the fissure dip angle increased.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Geosciences, Multidisciplinary
Dechao Zhang, Haicheng She, Taoli Xiao
Summary: The influence of fissure angles and bridge lengths on rock mechanical properties and failure was analyzed using the uniaxial compression test and the Digital Image Correlation (DIC) technique. The research findings indicate that the fissure angle has a more significant effect on a rock's mechanical properties than the length of the rock bridge. With an increase in the fissure angle, the number of surface cracks, main failure cracks, and surface spalling decreased, whereas the area of falling blocks significantly increased. At a low fissure angle, the failure mode of rock samples is dominated by tensile-failure cracks, but with an increase in fissure angle, a mixed tensile-shear damage mode is formed. These research results have important guiding value for engineering optimal designs.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Engineering, Mechanical
Ke-Sheng Li, Long-Xiao Chen, Zhen Zhao, Chuan-Xiao Liu
Summary: This study investigates the impact of fissure location on the properties of sandstone. The results show that pre-existing fissures significantly reduce the rock's mechanical properties. Moreover, flawed specimens exhibit distinct acoustic emission characteristics and energy evolution during the compression process.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Geochemistry & Geophysics
Yves Bernabe, Matej Pec
Summary: This study proposes a reformulation of the wing crack model for understanding brittle creep and failure in rocks. The model takes into account the complex mechanical interactions of sliding and tensile wing cracks and suggests that these interactions lead to the formation of micro shear bands, which in turn affect the overall behavior of the rock. The study found that the proposed model is consistent with published creep and failure data, and can also estimate the cohesion and angle of internal friction in materials.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Engineering, Geological
Haijun Wang, Lei Tang, Xuhua Ren, Chun Zhu, Bei Jiang, Qianqian Dong
Summary: This study introduces the 3D internal laser-engraved crack method to create internal cracks in glass and performs uniaxial tensile tests. A new grid reconstruction algorithm is proposed to simulate the coalescence and growth path of two coplanar internal cracks. The results show that the fracture in the test is static fracture and can be classified as Mode I fracture based on the fracture morphology. The observation of Wallner lines after coalescence indicates the rapid transformation of the new crack into an elliptical shape. Simulation confirms that the fracture in the test is Mode I, with normalized K-II/|K-Imax| and K-III/|K-Imax| values close to 0.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2023)
Article
Geochemistry & Geophysics
Cheng Song, Guorui Feng, Ruipeng Qian, Jiaqing Cui, Kai Wang, Xiaoze Wen, Jinwen Bai
Summary: The study demonstrates significant differences in strength and stiffness between saturated and dry specimens, with fissure angle and water jointly controlling the failure mode of fissured sandstone. The observed fracture evolution processes can be classified into six distinct stages for a better understanding of rock failure mechanisms. The presence of water accelerates the nucleation of microcracks, enlarges the range of microcrack coalescence, and facilitates the emergence of unstable cracks due to changes in pore water pressure and friction resistance.
Article
Engineering, Mechanical
Aman Arora, Aanchna Sharma, Mohit Singh, Dhiraj K. Mahajan, Vinod Kushvaha
Summary: This study presents an extensive experiment on the fatigue response of glass-filled epoxy composites under cyclic loading. Rod-shaped particulate glass fibers with volume fractions of 0%, 5%, 10%, and 15% are used to reinforce the epoxy matrix. The mechanical behavior of the resulting composite is examined under monotonic tensile loading and tension-tension cyclic fatigue loading. The study utilizes in-situ low cycle fatigue testing to investigate the damage mechanisms leading to crack initiation and propagation.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Multidisciplinary Sciences
Jiaqing Cui, Guorui Feng, Zhu Li, Yanna Han, Cheng Song, Xiaohong Niu, Xiaoze Wen
Summary: This study investigated the crack propagation characteristics of rock with cross-flaws in three different filling states using mechanical tests and observation techniques. The results showed that filling can inhibit crack propagation, stress drop, and improve the strength and stiffness of the rock.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2022)
Article
Mechanics
Jonas Rudshaug, Odd Sture Hopperstad, Tore Borvik
Summary: To develop accurate material models for glass, reliable experimental procedures are needed to capture the stochastic nature of the material. In this study, we conducted experiments on different windshields under quasi-static loading to reveal their stochastic behavior. We used 3D-Digital Image Correlation (3D-DIC) and high-speed cameras combined with pose estimation-based post-processing to monitor displacement field and capture fracture initiation and crack propagation data. Finite element simulations were also performed to estimate major principal stress values. The results from this study provided valuable data for the development of numerical models.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Nanoscience & Nanotechnology
Kejin Zhang, Shigeru Hamada, Kotaro Shindome, Tatsuo Yokoi, Hiroshi Noguchi
Summary: In this study, tensile tests were conducted to determine the strength of partially worked metals, revealing the behavior change caused by shear cracks during tensile loading. The presence of microscopis brittle fractures causing shear cracks was also observed in specimens exhibiting macroscopic brittle fracture.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Ceramics
Roman Papsik, Oldrich Sevecek, Eric Martin, Raul Bermejo
Summary: Crack initiation in brittle materials upon spherical indentation is influenced by tensile radial stresses during loading. The location of crack onset often differs from the site of maximal stress. The initiation forces and location of crack onset depend on geometrical parameters and surface condition. A coupled stress-energy fracture criterion is introduced in this work to describe the initiation of ring cracks in brittle materials, considering the geometry of the contact and the material's inherent strength and fracture toughness. The criterion can explain the location offset of the ring crack upon loading and predict the initiation force, provided surface compressive stresses are considered. The criterion can also estimate the surface residual stress of ceramic parts based on contact damage experiments.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Engineering, Geological
Shijie Li, Zhen Huang, Daoxue Yang, Wei Zeng, Kui Zhao
Summary: The acoustic characteristics of the rock failure process were studied to understand the evolution of different types of internal cracks. The study collected acoustic emission signals from yellow sandstone under uniaxial compression and analyzed the acoustic characteristics, crack types, and correlation dimension evolution. The analysis revealed the dominance of tensile cracks in the early stages and an increase in shear cracks during plastic deformation and post-peak failure. The energy of shear cracks was higher than that of tensile cracks and had a ratio within the range of 4.29-4.78. The correlation dimension showed changes during different stages, indicating significant changes in micro-crack types.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Yang Ju, Chaodong Xi, Jiangtao Zheng, Wenbo Gong, Jianhao Wu, Shaojie Wang, Lingtao Mao
Summary: Accurate understanding and quantification of the 3D water-oil displacement process in porous reservoir rocks is crucial for enhancing petroleum recovery efficiency. This study utilized X-ray computed tomography and triaxial loading techniques to directly visualize and quantify the pore-scale physics and dynamic evolution of the displacement behavior. The results demonstrate the significant impact of stress-induced pore structure deformation on the displacement behavior and efficiency, providing valuable insights for improving petroleum recovery strategies.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2022)
Article
Engineering, Multidisciplinary
Lingtao Mao, Yu Lei, Leilei Ding, Jingcheng Wu, Liyun Li, Min Yang, Yang Ju, Fu-pen Chiang
Summary: This study investigates the 3D interior deformation of siltstone specimens using a series of uniaxial compression tests combined with in situ X-ray computed tomography. The specimens had pre-existing 3D surface flaws with different inclination angles and a flaw depth to specimen thickness ratio of 0.26. Digital volumetric speckle photography was used to quantify the 3D interior deformation and determine the distribution of displacement and major principal strain in different sections. The findings reveal the propagation mechanism of a single 3D surface flaw.
Article
Engineering, Environmental
Kai Wang, Long Wang, Yang Ju, Huzi Dong, Wei Zhao, Changang Du, Yangyang Guo, Zhen Lou, Han Gao
Summary: The study focused on the air leakage model considering three-dimensional stress and coal elastic-plastic deformation to prevent air leakage caused by mining-induced fractures around the borehole and roadway, which greatly affects the effect of underground gas drainage. Key parameters including initial permeability and sealing depth were analyzed to understand their influence on gas drainage effect.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Construction & Building Technology
Yang Ju, Changbing Wan, Guoming Fu, Lingtao Mao, Fu-pen Chiang
Summary: A new photoelastic testing method was developed to directly observe and quantify the full-field stress distribution and evolution in assembled lining structures. Experimental results verified the effectiveness of the proposed method in characterizing stress distributions within complex assembled lining structures.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2022)
Review
Energy & Fuels
Bin Pan, Teng Ni, Weiyao Zhu, Yongfei Yang, Yang Ju, Lijie Zhang, Shengnan Chen, Jianwei Gu, Yajun Li, Stefan Iglauer
Summary: This article provides a critical review of the key parameter of wettability in the methane-liquid-rock system, discussing its influence from experimental and theoretical perspectives, including pressure and temperature conditions, fluid properties, and rock surface characteristics. The article identifies current research gaps, provides future outlook, and draws several conclusions. The mini review contributes to the fundamental understanding of wettability in the methane-liquid-rock system under in situ reservoir conditions and offers useful guidance for shale gas/coalbed methane recovery and natural gas geo-storage.
Article
Chemistry, Physical
Bin Pan, Xia Yin, Weiyao Zhu, Yongfei Yang, Yang Ju, Yujie Yuan, Lijie Zhang, Stefan Iglauer
Summary: This study conducted a fundamental analysis of secondary imbibition in gas geo-storage operations. It found that the rate of secondary imbibition depends on factors such as gas type, formation depth, organic acid concentration, carbon number, and silica nanofluid. The findings provide valuable insights for understanding and optimizing gas geo-storage processes.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Energy & Fuels
B. Balinee, P. G. Ranjith, Herbert E. Huppert
Summary: The article discusses the impact of building material production on global carbon emissions and presents methods to reduce environmental impact through the use of waste and carbon sequestration. By incorporating discarded aluminum foil and industrial waste gases into cement, the performance and sustainability of cement can be improved. This approach significantly reduces carbon emissions, lowers costs, and stores a large amount of CO2.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Computer Science, Interdisciplinary Applications
Sheng-Qi Yang, Ye Li, Guo-Wei Ma, Bo-Wen Sun, Jing Yang, Jie Xu, Yong-Hao Dai
Summary: The dynamic compression experiments were conducted on granite specimens after high-temperature treatments, and the fragmentation characteristics were evaluated using fractal dimension and average fragment size. The results showed that the physical properties of the granite were closely related to the temperature, and microcracking occurred at 900 degrees Celsius. The fractal dimension and average fragmentation size were found to be inversely linearly related, and the crack propagation during dynamic compression followed a pattern of initial appearance on the surface and gradual propagation to the interior.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Green & Sustainable Science & Technology
Jinzhou Tang, Shengqi Yang, Ke Yang, Wenling Tian, Guangjian Liu, Minke Duan
Summary: A new thermal damage numerical model was proposed to analyze the cracks on pre-cracked red sandstone after thermal treatment. The thermal damage value, obtained by extracting the thermal crack area from SEM images, served as an indicator of the degree of thermal damage. By replacing the flat-joint model with the smooth-joint model based on the thermal damage value, the mechanical behavior and failure patterns of sandstone were accurately simulated. In addition, the critical temperature for strength reduction was found to be 750 degrees C.
Article
Energy & Fuels
Sheng-Qi Yang, Shuai-Bo Xu, Zhen Liu, Bo-Wen Sun, Peng-Fei Yin
Summary: In this study, stress-strain curves of sandstone soaked in 5% NaCl and 5% K2SO4 solutions were obtained under different loading and unloading paths. The results showed that sandstone soaked in 5% NaCl exhibited greater unloading capacity compared to sandstone soaked in 5% K2SO4. The strain change rate during the unloading process was higher for sandstone soaked in 5% K2SO4. The deformation modulus and Poisson's ratio of sandstone soaked in 5% NaCl were greater and less than those of sandstone soaked in 5% K2SO4, respectively. The total energy absorbed by sandstone soaked in 5% NaCl was always lower than that soaked in 5% K2SO4.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2023)
Article
Energy & Fuels
Pengfei Yin, Shengqi Yang, Feng Gao, Wenling Tian
Summary: Drilling wellbores in shale reservoirs can lead to instability due to the stress release and change in stress equilibrium. This study investigated the strength, failure, strain energy evolution, and micro-crack damage of shale specimens under confining pressure unloading conditions. The research revealed that confining pressure unloading induces greater plastic deformation, more micro-crack damage, and a more complex failure pattern.
Editorial Material
Energy & Fuels
Chun Zhu, Shengqi Yang, Yuanyuan Pu, Lijun Sun, Min Wang, Kun Du
Article
Engineering, Geological
Yu Song, Sheng-Qi Yang, Ke-Sheng Li, Peng-Fei Yin, Peng-Zhi Pan
Summary: This study establishes a three-dimensional numerical model to investigate the failure behavior of transversely isotropic rock formations, with a focus on the effects of confining pressure and laminar inclination angle. The results of the numerical simulations show that the confining pressure and laminar angle significantly influence the internal crack evolution patterns of the specimen.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
V. R. S. De Silva, H. Konietzky, H. Mearten, P. G. Ranjith, W. G. P. Kumari
Summary: This study proposes a novel approach called the hybrid rock pre-conditioning method to enhance the sustainability and efficiency of low-grade ore mining. The method involves the use of soundless cracking demolition agents (SCDAs) to initiate radial fractures in a predrilled host rock, followed by hydraulic stimulation to extend the fractures. The results show that this method can create a high density of fractures around the injection well, and key factors such as rock mass heterogeneity and stress anisotropy affect its performance.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Energy & Fuels
M. H. Samarakoon, P. G. Ranjith
Summary: Ensuring the intactness of cement sheaths is crucial for deep well applications in extreme underground conditions. This study investigates the behavior of wellbore materials, including steel casing, annulus cement sheaths, and surrounding rock formations, under continuous steam injection. The results show that materials in carbonate formations are more vulnerable to stress than those in sandstone formations, and the retention time of maximum temperature in cement sheaths is shorter in sandstone than in carbonate. It is also found that the cement sheaths in compliant formations like sandstone may fail due to tensile cracking along the thinnest thickness.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
