Article
Engineering, Geological
Peng Huang, Jixiong Zhang, A. J. S. (Sam) Spearing, Jun Chai, Chaowei Dong
Summary: This study investigated the influence of initial damage on the creep behavior of coal samples, revealing that initial damage led to a gradual decrease in total creep time, deviating stress of creep failure, stress threshold of accelerated creep, and starting time of volume expansion during creep tests.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Multidisciplinary Sciences
Guanghe Li, Yanting Wang, Yiming Hu, Dong Wang, Xiaoxu Yang, Yanfei Li, Zhiwei Zhou, Shipeng Zhang
Summary: This study clarifies the shear creep characteristics of rock and establishes a new nonlinear shear creep damage model. The model can better describe the creep characteristics of rock under different normal and shear stresses, with superior performance in describing the accelerated creep stage compared to the classical model. The model has high agreement with experimental data, confirming its accuracy and rationality. The influence of model parameters on rock creep deformation is analyzed.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Geological
Bichuan Zhang, Yunpei Liang, Quanle Zou, Yanhao Ning, Zhiming Wang, Han Liu
Summary: Damage accumulation from cyclic loading and creep impacts in coal can result in rock failure and dynamic disasters. Quantifying this behavior is crucial for assessing mechanical response under creep and cyclic loading processes. Creep tests were performed after cyclic loading and unloading at 10 MPa confining pressure. Elastic modulus and Poisson's ratio indicated fatigue damage throughout the loading process, with higher moduli in the unloading stage and decreasing gap in Poisson's ratio during cyclic loading. The stress-strain response demonstrated hardening and softening effects under different axial stresses, with creep-hardening deformation observed. The coal near mining-induced stress boundary experienced cyclic damage and decreasing creep stress, suggesting the need for considering creep failure time and determining suitable boundaries to prevent dynamic disasters.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2023)
Article
Engineering, Chemical
Lei Zhang, Peng Huang, Sijia Liu, Gang He, Bing Li, Yuanwei Cao
Summary: This study proposes and applies a segmented hole-reaming technology in a coal mine to prevent rock bursts. By establishing a pressure-relief mechanic model, the impact of different parameters on the pressure relief range is analyzed, and the stress distribution is obtained. Experimental results demonstrate the effectiveness of the segmented hole-reaming technology in reducing pressure.
Article
Mechanics
Jinshuai Guo, Guangpei Zhang
Summary: This study investigates the creep damage characteristics of coal pillars using surrogate materials. The results show that the stress and deformation of the coal pillars change over time, ultimately leading to the collapse of the entire pillar.
MECHANICS OF TIME-DEPENDENT MATERIALS
(2023)
Article
Engineering, Multidisciplinary
Peng Huang, Jixiong Zhang, Ntigurirwa Jean Damascene, Chaowei Dong, Zhaojun Wang
Summary: An innovative initial damage coal sample test method was proposed to study the impact of initial damage on the creep characteristics of coal samples. The study found that with the increase of initial damage, the creep time of coal samples shortened and the rate of accelerated creep damage increased sharply. The established fractional viscosity coefficient relationship and improved creep model in the acceleration phase provided a better description of the creep characteristics of coal samples with initial damage.
ALEXANDRIA ENGINEERING JOURNAL
(2021)
Article
Engineering, Mechanical
Dao-Hang Li, De-Guang Shang, Xiang Yin, Ming Li, Feng Chen, Guo-Qin Sun, Wei Sun
Summary: A new life assessment framework is proposed based on elastic-viscoplastic modeling and damage behavior for structural components under multiaxial nonproportional loading at high temperature. The framework utilizes a viscoplastic constitutive model to capture non-proportional hardening effect and a damage model to assess failure life comprehensively. Evaluation of the framework at 650 degrees C shows errors within a factor of 2 under proportional and non-proportional fatigue loadings.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Metallurgy & Metallurgical Engineering
Jie-lin Li, Long-yin Zhu, Ke-ping Zhou, Hui Chen, Le Gao, Yun Lin, Yan-jun Shen
Summary: The study defines rock freeze-thaw and creep damage factors based on nuclear magnetic resonance porosity and volume strain, and establishes non-linear creep damage constitutive model and freeze-thaw rock equation. The continuous damage caused by freeze-thaw cycles weakens the rock viscoplasticity and reduces the long-term strength.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2021)
Article
Mechanics
Zhiming Zheng, Yu Yang, Cheng Pan
Summary: Rock creep is influenced by various environmental conditions and internal hardening and damage. This study introduces a creep parameter that considers the joint effect of hardening and damage using a dashpot in the Nishihara model. A modified creep model is established by connecting this dashpot to the modified Nishihara model, and it accurately predicts experimental creep data. The model overcomes the limitations of conventional spider models in describing accelerated creep properties and accurately describes creep curve and hardening-damage characteristics.
MECHANICS OF TIME-DEPENDENT MATERIALS
(2023)
Article
Environmental Sciences
Song Bing-tang, Liu En-long, Shi Zhao-yun, Wang Pan, Yu Qi-hao
Summary: The creep characteristics of frozen soils mixed with silty clay and coarse-grained sand are influenced by temperature, confining pressure, and coarse particle content. Under low confining pressure, specimens exhibit both attenuation creep and non-attenuation creep, while under high confining pressure, specimens show initial and stable creep stages. An improved Nishihara model incorporating hardening and damage variables can model the entire creep process of frozen soils with relative ease, with the effects of increasing coarse particle content leading to a reduction in both strengthening and damaged effects.
JOURNAL OF MOUNTAIN SCIENCE
(2021)
Article
Engineering, Environmental
Dongming Wang, Enyuan Wang, Xiaojun Feng, Mingyao Wei, Dexing Li, Quanlin Liu, Baolin Li, Xin Zhang
Summary: This study aims to quantitatively characterize the creep deformation and instability failure process of gas-bearing coal. Experimental results show that the degree of creep deformation of coal samples is closely related to the applied stress, and accelerated creep failure occurs when the stress level exceeds the long-term strength of the sample. The gas pressure significantly affects the creep characteristics of coal, and a model considering damage accumulation can quantitatively characterize the creep damage process of coal.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2022)
Article
Engineering, Mechanical
Sheng Shi, Feng Zhang, Decheng Feng
Summary: In cold regions, the creep behavior of frozen soil is important for evaluating engineering foundation stability. Frozen soil has more complex creep properties than unfrozen soil due to its cryogenic structures. This research conducted creep tests on heterogeneous frozen clay soil under different deviatoric stresses, and analyzed the influence of deviatoric stress and structural features on creep behaviors. Based on the test results and fracture mechanics, a new creep constitutive model considering cryostructure fracture was established for heterogeneous frozen clay soil, and its validity was verified using test results.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Energy & Fuels
Junbao Wang, Qiang Zhang, Zhanping Song, Shijin Feng, Yuwei Zhang
Summary: In this study, the creep response and unloading rebound effect of salt rock are explored through uniaxial compression creep and unloading rebound tests. A new nonlinear creep model is established and validated through numerical simulation and experimental testing.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Environmental Studies
Gensheng Li, Zhenqi Hu, Pengyu Li, Dongzhu Yuan, Wenjuan Wang, Kun Yang
Summary: This study analyzed the impact of coal mining on cropland and proposed key issues in optimizing coal mining and farmland protection. By examining the influences of various factors on surface ponding and cropland damage, recommendations to reduce mining width were suggested to achieve sustainable development.
Article
Energy & Fuels
Tingting Cai, Lei Shi, Yulong Jiang, Zengchao Feng
Summary: This paper establishes an improved core damage model for describing the evolution characteristics of coal in creep and stress relaxation processes, based on a comparison of traditional and improved component models. The model is validated using experimental data and shows great accuracy. Furthermore, a comparison with other models demonstrates that the core damage model has clear and concise physical significances and good generalizability.
Article
Mathematics, Interdisciplinary Applications
Lili Sui, Jian Yu, Dingbang Cang, Wenjing Miao, Heyuan Wang, Jiwei Zhang, Shuaifeng Yin, Keliang Chang
CHAOS SOLITONS & FRACTALS
(2019)
Article
Engineering, Geological
Ji-wei Zhang, Julian Murton, Shu-jie Liu, Li-li Sui, Song Zhang, Lei Wang, Ling-hui Kong, Hang Ding
Summary: Determining the physical properties between two freezing pipes during freezing using ultrasonic acoustic methods shows that wave velocity is sensitive to physical properties and dominant frequency is sensitive to temperature and water content. The established multiple regression model can predict the relationship between wave velocity and temperature.
QUARTERLY JOURNAL OF ENGINEERING GEOLOGY AND HYDROGEOLOGY
(2021)
Article
Geography, Physical
Ji-wei Zhang, Julian Murton, Shu-jie Liu, Li-li Sui, Song Zhang
Summary: A novel experimental design was reported to monitor the movement of cryofront, water migration, and acoustic parameters during progressive upward freezing of fine sand. Ultrasonic testing revealed changes in wave velocity, wave amplitude, and frequency spectrum during different stages of freezing, providing valuable information for assessing the freezing state and thickness of artificial frozen walls.
PERMAFROST AND PERIGLACIAL PROCESSES
(2021)
Article
Engineering, Geological
Jiwei Zhang, Julian Murton, Tim Cane, Vikram Maji, Lili Sui, Shujie Liu, Song Zhang
Summary: Common problems in engineering projects involving artificial ground freezing of soil or rock include inadequate thickness, strength, and continuity of frozen walls. Evaluating the freezing state is challenging using limited thermometer holes or existing approaches. This study proposes a novel experimental design using ultrasonic properties to determine the freezing state in sandstone blocks. It investigates changes in received waveform, wave velocity, frequency spectrum, and other parameters during upward freezing compared to uniform freezing. The findings demonstrate the utility of frequency spectrum for identifying different freezing states and propose ultrasonic parameters for quantitatively evaluating temperature and frost front height in frozen sandstone.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2023)
Article
Geochemistry & Geophysics
Song Zhang, Xiao-min Zhou, Jiwei Zhang, Tiecheng Sun, Wenzhu Ma, Yong Liu, Ning Yang
Summary: This study identifies the applicability and superiority of intermittent freezing in large-scale shallow buried freezing projects, and proposes optimization schemes for increasing the thickness of the freezing wall and average temperature. It also suggests specific measures for frost heave control.
Article
Energy & Fuels
Shu-jie Liu, Xiao-min Zhou, Ji-wei Zhang, Zuo-dong Xie
Summary: A theoretical model of directional drilling trajectories is proposed in this study, and the optimum trajectory for directional drilling is designed using an optimization algorithm. The results show that the optimization algorithm is more intuitive and reliable than repetition tests and traditional human-computer interaction techniques.
Article
Energy & Fuels
Zhang Jiwei, Li Fangzheng, Liu Shujie, Wu Wei-dong, Yu Xinhao
Summary: The study found that the cracking potential of inner lining concrete slightly increases with the increase of concrete strength, but it increases significantly once the strength exceeds C70. The crack indicators at different concrete strengths fluctuate slightly as the concrete strength increases, but overall, an increase in concrete strength decreases the cracking potential of inner lining concrete under steel frame restrained condition.
Article
Chemistry, Physical
Shujie Liu, Jinze Sun, Jiwei Zhang, Zuodong Xie, Zhijie Yu
Summary: In this study, a novel clay-cement slurry enhanced with graphene oxide (GO) as a modifier was developed. The addition of GO significantly increased the viscosity and plastic strength of the slurry as well as improved its stability. The stone body of the GO-modified slurry exhibited higher compressive and shear strength, indicating enhanced durability. The microstructure analysis revealed that the addition of GO led to the formation of a clay-cement agglomerate space skeleton, contributing to the superior performance of the modified slurry.
Article
Mathematics, Interdisciplinary Applications
Lili Sui, Heyuan Wang, Jinsui Wu, Jiwei Zhang, Jian Yu, Xinyu Ma, Qiji Sun
Summary: Fractal characteristics and the fractal dimension are widely used in describing and characterizing rock fracture networks for various engineering purposes. This paper reviews traditional fractal calculation methods and proposes a new simple method based on the head/tail breaks approach. It is found that rock fracture networks share similarities with urban road traffic networks, and the application of space syntax metric can effectively reflect the spatial relationship of rock fractures.
FRACTAL AND FRACTIONAL
(2022)
Proceedings Paper
Energy & Fuels
Zhang Ji-wei, Zhang Song, Liu Shu-jie, Wang Hua
2019 5TH INTERNATIONAL CONFERENCE ON ADVANCES IN ENERGY RESOURCES AND ENVIRONMENT ENGINEERING (ICAESEE 2019)
(2020)
Proceedings Paper
Energy & Fuels
Song Zhang, Jiwei Zhang, Yufu Han, Yanlin Su, Hanhong Wen
2019 5TH INTERNATIONAL CONFERENCE ON ADVANCES IN ENERGY RESOURCES AND ENVIRONMENT ENGINEERING (ICAESEE 2019)
(2020)
Article
Energy & Fuels
Mokhtar Benasla, Imane Boukhatem, Tayeb Allaoui, Abderrahmane Berkani, Petr Korba, Felix Rafael Segundo Sevilla, Mohamed Belfedel
Summary: The idea of exporting dispatchable solar electricity from the North African region to Europe is still being discussed. This paper focuses on the potential of Algeria as a supplier and analyzes possible import corridors and barriers.
Article
Energy & Fuels
Hobyung Chae, Sangmu Bae, Jae-Weon Jeong, Yujin Nam
Summary: Thermoelectric generators (TEGs) utilize temperature differences to produce electricity and have potential for various industrial applications. This study introduces an advanced technique that utilizes temperature gradients in water pipes to increase power generation, with efficient modulation of output power through flow control. The feasibility evaluation in residential settings shows that TEGs can generate 10.95 kWh of electricity per unit, and to achieve zero-energy buildings, 64.5 m2 of TEG deployment is required per unit given a zT value of 1.
Review
Energy & Fuels
Lina Patricia Vega, Karen Tatiana Bautista, Heliana Campos, Sebastian Daza, Guillermo Vargas
Summary: This article focuses on the current situation of biofuel production and research development in Latin American countries such as Argentina, Brazil, Mexico, Chile, Costa Rica, and Colombia. Brazil stands out as a leader in the region, making significant advancements in clean energy production through biofuels policy implementation. The review highlights the challenges these countries face in utilizing their comparative advantages for biofuel production.
Article
Energy & Fuels
Iraj Faraji Davoudkhani, Mahmoud Rerza Shakarami, Almoataz Y. Abdelaziz, Adel El-Shahat
Summary: This paper presents an optimization-based method for designing a wide-area damping controller (WADC) based on remote signals to improve the damping of inter-area oscillations by considering the time delays. The grey wolf optimization (GWO) algorithm is utilized to solve the optimization problem, and simulations and statistical results demonstrate the superiority of the proposed method.
Article
Energy & Fuels
Majid Ahmed Mohammed, Bashar Mahmood Ali, Khalil Farhan Yassin, Obed Majeed Ali, Omar Rafae Alomar
Summary: This study compares the effects of different phase change materials on the performance of solar panels. The experiment shows that the use of beeswax can lower the temperature of the panel and increase the efficiency of the photovoltaic system.