Article
Engineering, Mechanical
Xiao-Ping Zhou, Sen-Lin Peng, Jian-Zhi Zhang, Jian-Nan Zhou, Filippo Berto
Summary: This study analyzes the effects of materials and confining pressures on the mechanical properties of flawed coarse and fine sandstone. It investigates the spatiotemporal acoustic emission (AE) events and ultimate failure modes of sandstone specimens with two flaws under biaxial compression, and observes the main macro-fracture surfaces using Electron Probe Microscope Analysis (EPEI) technique. The distribution characteristics of two AE indexes are also used to reveal the failure mechanism. The experimental results provide insight into the behavior of flawed rocks under complex stress loading conditions.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Construction & Building Technology
Zhao-Qi Li, Hongyun Chen, Jie Dong, Xin Yan, Shi-Rong Zhao, Ying-Hao Zheng, Yang Liu
Summary: This paper presents an extensive experimental study on the compressive failure of different types of aggregates and their influence on the interfacial properties of mortars. The interfacial debonding was identified as the main failure mode of mortar rubbles, with varying interlocking strength of aggregate and mortar affecting the compressive strength of materials. The highest instantaneous AE energy was observed in granite mortar rubble, with acoustic emissions strongest in the 150-220 kHz range, providing an early warning of damage load at high frequencies.
Article
Construction & Building Technology
Jie Xu, Xianli Niu, Ziyi Yao
Summary: This study analyzed the mechanical properties and acoustic emission parameters of crumb rubber concrete (CRC) with different rubber contents under biaxial compression stress states. The modified Kupfer failure criterions were proposed to describe the strength growth laws of CRC, and the initiation and growth of concrete cracks were monitored based on AE technology. The study provides experimental and theoretical foundations for the strength analyses and failure characteristics of CRC structures under complex stress states.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Kun Du, Minghui Liu, Chengzhi Yang, Ming Tao, Fukang Feng, Shaofeng Wang
Summary: This study investigates the mechanical characteristics and acoustic emission properties of granite, marble, and sandstone under biaxial compression tests. It shows that under biaxial confinement, the elastic moduli decrease, plasticity increases, and the biaxial compressive strength of rock initially increases then decreases with the increase of the intermediate principal stress. The study also found that the behavior of rocks under biaxial confinement is influenced by both the sigma(1) and sigma(2) stresses, and the failure modes of different rock types differ under such conditions.
APPLIED SCIENCES-BASEL
(2021)
Article
Construction & Building Technology
Yubo Jiao, Wenlong Du, Hua Yang, Hongjun Shi
Summary: This study investigated the reinforcing effect of glass fiber on failure behavior of asphalt concrete at low temperature using AE and DIC techniques. The results showed that AE parameters could effectively classify and characterize the failure processes. The effect of fiber length on the failure process was also studied.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2024)
Article
Mechanics
Qi Liang, Jingyan Liu, Xiaoxu Wang, Xiaodong Liu, Diantang Zhang, Kun Qian
Summary: The study experimentally tested three types of 3D angle-interlock woven composites and found that hybrid structures have significant effects on mechanical behaviors, damage models, and failure mechanisms. Delamination, fiber fracture matrix cracking, and debonding are dominant failure mechanisms for hybrid 90 degrees specimens, while matrix cracking and fiber matrix debonding are predominant for hybrid 0 degrees specimens.
COMPOSITE STRUCTURES
(2022)
Article
Geosciences, Multidisciplinary
Yan Cheng, Paul Hagan, Rudrajit Mitra, Shuren Wang, Hong-Wei Yang
Summary: This paper explores the potential of 3D acoustic emission (AE) tomography in demonstrating fracture development and delineating stress conditions. Brazilian tests and uniaxial compression tests were monitored using 3D AE tomography, with analysis of AE counts, source locations, 3D tomographic images, and stress and strain measurements. The results highlighted distinct failure processes, correlation of micro-crack development with theoretical analysis and experimental observations, as well as the ability of AE locations and velocity tomography to indicate stress patterns, failure modes and final failure planes. Three-dimensional velocity tomographic images also revealed sample anisotropy caused by stresses.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Engineering, Geological
Yirui Gao, Yixin Zhao, Hao Wang, Bin Liu, Philipp Hartlieb, Sen Gao
Summary: The combined influence of microwave energy and load on the failure characteristics of coal reservoirs was investigated using acoustic emission (AE) technology. Microwave irradiation significantly affected the AE activity of anthracite under loading, and changed the failure mode of anthracite from shear failure to tensile failure. The study results have great significance for optimizing the scheme of microwave-assisted CBM extraction and improving the CBM production rate.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Chaoqun Chu, Shunchuan Wu, Chaojun Zhang, Yongle Zhang
Summary: The anisotropy induced by rock bedding structures affects the mechanical behaviors and failure modes of rocks, as shown by Brazilian tests on shale specimens with different bedding angles. Acoustic emission and digital image correlation technologies were used to monitor in-situ failure, while scanning electron microscopy was used to observe crack morphology. The results revealed the structural dependence of shale's tensile mechanical behavior, with compression occurring in the early stage of the experiment and the location of the compression area moving downward and disappearing as the bedding angle increased. The dominant frequency distribution and b-value were found to be related to the bedding angle, and crack turning angle and number increased with the bedding angle, indicating competition between crack propagations. SEM results classified the failure modes into three types.
INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Eleni Tsangouri, Corentin Van Loo, Yasmina Shields, Nele De Belie, Kim Van Tittelboom, Dimitrios G. Aggelis
Summary: This work presents a novel linear reservoir-vascular tubes network and explores its design efficacy through testing of concrete beams and assessing their damage healing and mechanical recovery. The study demonstrates that 3D printed polymer-tubes are equally effective as conventional ceramic tubes for crack healing in concrete. The sealed cracks show significant strength and toughness recovery, accompanied by an increase in ultrasound pulse velocity. However, there are obstructions in the current design, including tube clogging and the formation of vacuum spaces during casting.
APPLIED SCIENCES-BASEL
(2022)
Article
Materials Science, Ceramics
Fei Wang, Xuefeng Teng, Xiaoan Hu, Yun Jiang, Xiaojun Guo, Longbiao Li, Xiaochong Liu, Xin Liu, Hongyi Lu
Summary: This paper investigates the damage evolution and failure process of a SiCf/SiC CMC through DIC and AE methods. The results show that macro-matrix cracks and fiber fractures occur as different damage modes, affecting the AE energy signal. The significant increase in AE accumulated energy indicates severe internal damage, resulting in nonlinear macroscopic mechanical behavior.
CERAMICS INTERNATIONAL
(2022)
Article
Mechanics
Khalil Hamdi, Gurvan Moreau, Zoheir Aboura
Summary: This study investigated the compressive mechanical properties and damaging scenario of two types of CFRP with different resins. Multiple techniques were used to analyze the damage progression, showing that the resin had a minor effect on the overall compression behavior of the composites. Signal processing tools were utilized to cluster acoustic emission signals and identify the beginning of severe damage based on the matrix type.
COMPOSITE STRUCTURES
(2021)
Article
Mechanics
Lukasz Pyrzowski, Magdalena Knak, Magdalena Rucka
Summary: This paper presents an experimental study on the failure behavior of sandwich beams subjected to bending. The samples used are sandwich beams made of polyethylene terephthalate foam core and glass fiber-reinforced polymer laminate face sheets. In a series of experiments, the integration of diagnostic techniques with acoustic emission and digital image correlation has been proposed to accurately track the cracking process on the surface as well as in the entire volume of the beam. The research program carried out allowed for the observation of various modes of failure in composite specimens. The results obtained showed that the integration of acoustic and optical diagnostic techniques provided complementary results and can be successfully used for failure monitoring in sandwich beams.
COMPOSITE STRUCTURES
(2023)
Article
Geosciences, Multidisciplinary
Yongsong Lu, Peifeng Li, Wei Cai
Summary: This study examined the evolutionary characteristics of acoustic signals produced by granite under biaxial compression. The results showed distinct differences in precursors among different acoustic signals and a strong influence of intermediate principal stress on these precursors. The findings are significant for the prediction and warning of geological disasters in deep underground engineering.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Engineering, Geological
Ghasem Shams, Patrice Rivard, Omid Moradian
Summary: This study investigated the microcracking processes in granite specimens under indirect (Brazilian) and direct tensile loadings. It was found that the ultimate tensile macro-fracture was predominantly composed of shear microcracks in Brazilian tests and tensile microcracks in direct tension tests. The different contributions of shear and tensile microcracks explain the difference in tensile strengths. The findings of this study have implications for rock fracture applications such as hydraulic fracturing for geothermal energy extraction.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
K. H. S. M. Sampath, M. S. A. Perera, D. Elsworth, S. K. Matthai, P. G. Ranjith, Li Dong-yin
Summary: CO2 interaction with coal causes complex mechanical deformations and flow modifications, affecting gas permeability in coal seams. The study shows that high-permeability fracture pathways provide easy access for CO2 diffusion into the coal matrix, leading to sorption-induced matrix swelling. The reduction in fracture aperture depends on the swelling behavior of the bounding matrix, causing full closure of small fractures and localized flow modifications.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Geological
K. M. A. S. Bandara, P. G. Ranjith, W. G. P. Kumari
Summary: The study revealed that fractures generated in shale and siltstone formations during hydraulic fracturing exhibit different characteristics, and flow behavior is influenced by factors such as fracture tortuosity and proppant concentration.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Environmental
Yi Xue, Jia Liu, P. G. Ranjith, Zhizhen Zhang, Feng Gao, Songhe Wang
Summary: This study conducted triaxial compression tests on coal under different gas pressure conditions to explore the influence mechanism of gas pressure on coal deformation, failure, and energy evolution. The mechanical properties, acoustic emission energy characteristics, and nonlinear characteristics of coal containing gas were obtained based on the test data. A theoretical formula for analyzing energy evolution was introduced and verified by test data. The research results indicate that energy rate can be used as a new effective mechanical parameter to analyze and predict the damage and failure characteristics of coal. The findings on energy dissipation characteristics and the defined ratio of dissipative energy rate and input energy rate provide insights for understanding the fracturing evolution and energy driving mechanism of coal.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Construction & Building Technology
M. H. Samarakoon, P. G. Ranjith, W. A. M. Wanniarachchi
Summary: This study examines the effects of carbonation on the properties and mechanisms of cement, showing that alkali-activated cements with higher calcium content exhibit better mechanical properties and a denser microstructure when exposed to carbonate brine.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Thermodynamics
Jizhao Xu, Cheng Zhai, Pathegama Gamage Ranjith, Shuxun Sang, Yong Sun, Yuzhou Cong, Wei Tang, Yangfeng Zheng
Summary: The study investigated the effects of liquid CO2 on coal strength, finding that the coupled effects of liquid CO2 temperature and adsorption can influence coal fracture behavior and crack morphology.
Article
Energy & Fuels
Jizhao Xu, Cheng Zhai, P. G. Ranjith, Shuxun Sang, Xu Yu, Yong Sun, Yuzhou Cong, Yangfeng Zheng, Wei Tang
Summary: The study found that coal affected by liquid CO2 exhibited more complex destruction patterns, larger fractal dimensions, and greater structure degradation. The affected coals showed diverse mechanical responses, with temperature shock and CO2 adsorption potentially leading to crack growth and strength deterioration, ultimately destroying the coal with smaller yield strength.
Article
Energy & Fuels
David Lall, Vikram Vishal, M. V. Lall, P. G. Ranjith
Summary: The study found that gas production was less efficient in the presence of a permeable heterogeneity compared to other scenarios. The permeability affects the vertical extent of dissolved methane volume during thermal stimulation and huff and puff, while well depth influences the radial extent of dissociated molecules.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Geological
Chunlin Zhong, Zhenyu Zhang, P. G. Ranjith, Chengpeng Zhang, Kangsheng Xue
Summary: The study found that pore water can affect the radial and volumetric strain evolution of coal, leading to dilation deformation. Additionally, due to the water propping effect, the cracks in saturated coal cannot close tightly during loading, causing sliding and generating numerous tensile cracks. Loading frequency can impact the decay of pore pressure, consequently influencing the number of cracks in coal.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Energy & Fuels
Shashika Gajanayake, Ranjith Pathegama Gamage, Pabasara Wanniarachchige, Decheng Zhang
Summary: This study conducted molecular dynamic simulations to investigate the effects of temperature, pressure, and initial CO2 concentration on gas replacement characteristics for methane recovery and CO2 storage. The results showed that higher temperatures resulted in greater methane recovery, but diminished CO2 storage capacity. Higher initial CO2 concentrations facilitated better CO2 penetration into the hydrate structure, leading to increased methane recovery and improved CO2 storage.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2022)
Article
Thermodynamics
P. Cheng, C. P. Zhang, Z. Y. Ma, J. P. Zhou, D. C. Zhang, X. F. Liu, H. Chen, P. G. Ranjith
Summary: Nanoindentation tests were conducted to investigate the effects of ScCO2-water treatment on shale matrix micromechanics, revealing significant heterogeneity in the properties of different minerals. Observation of indentation morphologies showed that considerable micro-fractures were generated in clay minerals, correlated to significant plastic deformation and layered crystal structures.
Article
Engineering, Geological
K. M. A. S. Bandara, P. G. Ranjith, W. Zheng, D. D. Tannant, V. R. S. De Silva, T. D. Rathnaweera
Summary: This study provides a grain-scale analysis of the fracture evolution mechanisms of proppant crushing, rock fracture damage during proppant embedment, and the influence of realistic reservoir/fracture fluid on proppant embedment. The results reveal that the selection of an appropriate proppant type is vital in quantifying the degree of proppant crushing and embedment within fractures.
Article
Thermodynamics
Guanglei Zhang, P. G. Ranjith, Qiao Lyu
Summary: This study reveals the effects of CO2 on the micro and nano-scale properties of coal, confirms the softening effects of CO2 on coal, and indicates that these changes are reversible to some extent.
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
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)
Article
Mechanics
Xiaolong Liu, Kelian Luo, Pengcheng Gao, Tao Cong, Xi Wang, Wenjing Wang
Summary: This paper investigates the formation mechanisms of the zig-zag crack region on the shattered rim of railway wheels. The zig-zag crack region, identified as a typical region for crack propagation in rolling contact fatigue behavior, was observed using scanning electron microscopy and transmission electron microscopy. The formation of the zig-zag morphology is attributed to the periodic deflection of the propagation path relative to the initial propagation plane, caused by the limited plastic deformation zone at the crack tip. Grain refinement and secondary cracks in the zig-zag crack region are a result of the large compressive and shear stresses induced by rolling contact loading.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Anastasia Iziumova, Aleksei Vshivkov, Ivan Panteleev, Virginia Mubassarova, Oleg Plekhov, Denis Davydov
Summary: The aim of this study was to investigate the correlation between structural, acoustic emission, and thermal characteristics of fatigue crack growth in titanium alloys. Cluster analysis of the acoustic emission signals revealed two different types of signals observed during the fatigue crack development. It was experimentally demonstrated that the stored energy tends to reach an asymptotic value at the final stage of fatigue crack growth and this is correlated with the twinning process intensification in titanium alloy Ti Grade 2. A correlation was assumed between the stages of change in heat flux, the cumulative energy of the first cluster of acoustic emission signals, and the crack length.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
M. Vieira de Carvalho, I. A. Rodrigues Lopes, F. M. Andrade Pires
Summary: This study investigates the numerical challenges of fracture mechanics models within implicit quasi-static frameworks and proposes an instability criterion. The ratio of cohesive to internal power is identified as a crucial factor. Two strategies for handling fracture problems with instabilities are discussed and a comparative assessment is performed. The study also examines more complex material responses, including transformation-induced plasticity effects.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Thomas Duminy, Aurelien Doitrand, Sylvain Meille
Summary: This study conducted in situ wedge splitting tests on millimeter-size PMMA samples and proposed a method to determine the material tensile strength and critical energy release rate using digital image correlation and a full finite element implementation of the coupled criterion.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Xin Chang, Xingyi Wang, Chunhe Yang, Yintong Guo, Yanghui Wan
Summary: The influence of cyclic thermal shock and high-temperature acid etching on the Mode I fracture of shale was investigated in this study. It was found that cyclic thermal shock severely degrades the strength and fracture toughness of shale, while high-temperature acid etching treatment improves the fracture toughness. These findings are valuable for optimizing process parameters to reduce initiation pressure in deep shale formations.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Liaojun Yao, Mingyue Chuai, Zhangming Lyu, Xiangming Chen, Licheng Guo, R. C. Alderliesten
Summary: Methods based on fracture mechanics have been widely used in fatigue delamination growth (FDG) characterization of composite laminates. This study proposes appropriate similitude parameters to represent FDG behavior with different R-ratios.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Zesheng Zang, Zhonghui Li, Yue Niu, Shan Yin
Summary: This study conducted experiments and recorded signals to investigate the fracture behavior and damage evolution characteristics of coal samples. The results showed that as loading proceeds, the stress, electric potential (EP), and acoustic emission (AE) values increase, and EP and AE signals are excited when stress drops. The fracture behavior of coal samples is altered by flaw inclination, and the destruction mode becomes increasingly complicated. The damage evolution characteristics of coal samples can be evaluated and analyzed by defining the coefficient of variation (CV value) of EP and the b value of AE.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Clotilde Berdin, Nathalie Prud'homme
Summary: In this study, zirconia layers with different fractions of tetragonal phase and thicknesses were tested for multi-cracking behavior. Cracks perpendicular to the tensile direction were observed, showing a blunting effect into the substrate. The ratio of crack spacing at saturation to layer thickness decreased as the layer thickness increased. Unit cell modeling was used to establish a relationship between crack spacing and layer strength, which fell within the bounds of Hu and Evans model and was found to be insensitive to the tetragonal zirconia fraction.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Huadong Zhang, Weichen Kong, Y. H. Liu, Yuh J. Chao
Summary: Williams' series expansion crack tip solution in linear elasticity is modified to include a uniform crack face pressure. Practical methods to calculate T-stress from near crack tip stresses are outlined. The analytical results are consistent with numerical results.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Jiahao Kong, Haoyue Han, Tao Wang, Guangyan Huang, Zhuo Zhuang
Summary: This paper introduces a phase-field model for polymer foam materials by combining the phase-field method with the crushable foam model. The model is calibrated using experimental data and successfully simulates the fracture processes of polyurethane under different loading conditions. The study is important for the engineering applications of polymer foam materials.
ENGINEERING FRACTURE MECHANICS
(2024)
