Article
Chemistry, Multidisciplinary
Zhushuai Wang, Yu Yang, Yu Xu, Changhao Xin, Pengfei Liang, Ning Guo
Summary: This paper investigates the energy evolution and acoustic emission characteristics of rocks under different cyclic loading and unloading paths. The results show that the elastic energy, dissipative energy, and total energy of rocks are positively correlated with the number of cycles under both types of paths. The gradual accumulation of dissipative energy ultimately leads to rock failure. The study also reveals that rock damage is more severe under the variable lower limit cyclic loading and unloading path.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Geological
Xin Zhou, Xiaofei Liu, Xiaoran Wang, Yubing Liu, Hui Xie, Pengfei Du
Summary: This study investigates the instability failure mechanism and precursory response of coal under triaxial loading and unloading disturbance using acoustic emission (AE) monitoring. The results show that dynamic disturbance loads accelerate the deformation process of coal specimen and increase the occurrence of large-magnitude cracking events. Shear cracks are found to be the critical factor affecting the instability and failure of the loaded coal specimen. The b value and beta(t) value can reflect the time-varying evolution process of internal damage and can be used as indicators for coal instability and failure.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Mingtao Gao, Hongyu Yan, Huiqiang Duan, Si Xiong
Summary: This study conducted experimental tests on the mechanical properties and acoustic emission characteristics of low-strength coal specimens during cyclic loading and unloading, providing theoretical support for understanding the damage evolution of coal specimens.
APPLIED SCIENCES-BASEL
(2022)
Article
Green & Sustainable Science & Technology
Yong Wang, Chuan Deng, Zeng Ding, Feng He, Xiaojun Feng, Dongming Wang, Qinjing Hu, Xue Zhao
Summary: This study investigates the damage characteristics of sandstone, focusing on the precursor characteristics of acoustic emission (AE) under cyclic loading and unloading. The results show that the number of cycles has a significant impact on the behavior of sandstone, with a rapid increase in damage degree and energy value as the cycles increase. The AE ringing count is found to be more sensitive to damage than energy. Additionally, the study identifies the characteristics of AE waveform signals, which can be used as precursor characteristics for sandstone failure and instability.
Article
Chemistry, Physical
Xuexu An, Zhiping Hu, Liang Zhang, Anlong Liu, Yonghui Zhang, Fangtao Li
Summary: This paper investigates the internal nonlinear damage evolution characteristics of diorite samples under different unloading confining-pressure rates. The results reveal the nonlinear damage evolution mechanism of diorite under loading and unloading conditions.
Article
Construction & Building Technology
Bing Sun, Haowei Yang, Junwei Fan, Xiling Liu, Sheng Zeng
Summary: Three stress path tests were conducted to study the deformation and failure characteristics of rocks under different cyclic loading and unloading paths, with simultaneous acoustic emission (AE) monitoring. The mechanical and AE characteristics under different stress paths were analyzed, along with their influence on energy dissipation and deformation damage. The research obtained the law of energy evolution considering viscoelasticity under different stress paths, proposed the concept and calculation method of ultimate damage energy, and validated the calculation method through the compatibility of damage variable evolution based on damage energy. These research results lay a theoretical foundation for geotechnical engineering design and construction.
Article
Construction & Building Technology
Hernan Xargay, Marianela Ripani, Paula Folino, Nicolas Nunez, Antonio Caggiano
Summary: This study investigates the use of acoustic emissions in reinforced concrete beams to assess structural responses and damage evolution. The addition of steel fibers enhanced shear strength in the beams by restricting the development of inclined cracks.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Geological
Tingjiang Tan, Enyuan Wang, Xiaoran Wang, Liuzhu Ma, Wenli Yao
Summary: Studying the failure and damage evolution of water-saturated coal under cyclic loading is crucial for the stability of underground coal mining. This study conducted single-axis cyclic loading and unloading tests on water-saturated coal and analyzed the relationship between resistivity and strain field using Digital Image Correlation (DIC). They quantitatively characterized the damage in coal cyclic loading based on electrical resistivity and established damage constitutive equations. The results show that the resistivity and DIC responses are regular and complementary, providing valuable insights into the damage mechanism of coal and rock under complex stresses.
ENGINEERING GEOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Su Zhili, Jing Shengguo, Xie Wenbing, Tang Qingteng
Summary: This study deeply analyzes the acoustic emission, energy, and damage evolution of coal samples under different uniaxial cyclic loading and unloading conditions. It is found that increasing the amplitude of cyclic loading has a significant damage effect on coal samples. The damage of coal samples is influenced by stress path and external load.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Energy & Fuels
Hongying Tan, Hejuan Liu, Xilin Shi, Hongling Ma, Xiaosong Qiu, Yintong Guo, Shengnan Ban
Summary: This paper investigates the mechanical and acoustic responses of low-permeability sandstone under different confining pressures through multistage triaxial loading-unloading tests, and reveals the evolution laws of its mechanical behavior and acoustic emission parameters.
Article
Engineering, Geological
Anlin Zhang, Heping Xie, Ru Zhang, Mingzhong Gao, Jing Xie, Zheqiang Jia, Li Ren, Zetian Zhang
Summary: This research comprehensively analyzed the mechanical behavior of coal at different depths during mining through experiments. The results showed that with increasing depth, the strength and deformation of coal increased, the evolution of the Poisson's ratio presented a nonlinear increase, and the elastic modulus gradually decreased. The plastic deformation and progressive damage characteristics of the coal became more significant. The analysis of acoustic emission monitoring revealed that shallow coal samples failed mainly due to tensile cracking, while deep coal samples failed due to shear cracking. The energy evolution and partition characteristics were also investigated, showing an increase in the storage capacity of elastic strain energy with depth. The study also found that the damage development process of deeper coal was slower, but the damage degree was more serious. An improved damage model considering the depth effect was established. The model prediction curves agreed well with the testing values.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Construction & Building Technology
Tongyang Zhao, Wanpeng Huang, Fei Xue, Mingtao Gao, Huanyu Li, Shilei Liu, Le Sui
Summary: This study comprehensively investigates the effects of cyclic loads on the bolt-slurry interface in a mining project. It reveals the damage mechanism and acoustic emission characteristics of the interface, providing valuable insights for the design and monitoring of anchor bolts in different cyclic load conditions.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Geological
Zhengyang Song, Heinz Konietzky, Yunfeng Wu, Kun Du, Xin Cai
Summary: This study investigates the mechanical behavior of medium-grained sandstones under cyclic loading with different loading/unloading rates, using a testing method called differential cyclic loading. The experiments analyze the axial strain evolution and energy dissipation for different loading/unloading rates and maximum cyclic load level. The correlations between P-wave velocities and rock strengths are compared with existing data, and the relationships between final strength, axial strain at failure, and loading patterns are discussed. A rough assessment of the remaining fatigue life is also introduced.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2022)
Article
Engineering, Geological
Z. W. Ding, J. D. Jia, Q. B. Tang, X. F. Li
Summary: This study systematically explores the mechanical properties and damage evolution law of coal samples under cyclic loading. The experimental results indicate that cyclic loading enhances the strength of coal masses and leads to more severe failure modes. The input energy and elastic energy increase rapidly with axial stress, while dissipation energy increases slowly. The critical value of the damage variable and the settlement of coal samples are also related to the stress level.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Mechanical
Hang Li, Hongling Ma, Chunhe Yang, Kai Zhao, Zhiwen Hu, J. J. K. Daemen
Summary: This study conducted cyclic loading experiments on impure Huai'an rock salt and monitored acoustic emissions in real-time. The results showed that as the loading stress increased, the cumulative acoustic emission energy increased stepwise, with a band pattern of low, medium, and high frequencies. The proportion of high-frequency signals decreased while that of low-frequency signals increased. The constant lower limit stress caused higher cumulative acoustic emission energy and amplitude, and smaller b-values for the salt samples, indicating increased cracks and damage. The primary mode of failure for rock salt under cyclic loading was found to be tensile cracking, with shear cracks promoted by the constant lower limit stress.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Energy & Fuels
Hongru Li, Rongxi Shen, Dexing Li, Haishan Jia, Taixun Li, Tongqing Chen, Zhenhai Hou
Article
Geochemistry & Geophysics
Rongxi Shen, Hongru Li, Enyuan Wang, Dexing Li, Zhenhai Hou, Xuan Zhang, Xu Han
JOURNAL OF GEOPHYSICS AND ENGINEERING
(2019)
Article
Engineering, Industrial
Rongxi Shen, Liming Qiu, Enlai Zhao, Xu Han, Hongru Li, Zhenhai Hou, Xuan Zhang
Article
Engineering, Geological
Hongru Li, Rongxi Shen, Enyuan Wang, Dexing Li, Taixun Li, Tongqing Chen, Zhenhai Hou
ENGINEERING GEOLOGY
(2020)
Article
Engineering, Geological
Rongxi Shen, Hongru Li, Enyuan Wang, Tongqing Chen, Taixun Li, He Tian, Zhenhai Hou
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2020)
Article
Engineering, Geological
Hongru Li, Yafei Qiao, Rongxi Shen, Manchao He, Tai Cheng, Yingming Xiao, Jie Tang
Summary: The study reveals that water content significantly affects the mechanical behavior and acoustic emission signals of sandstone, with increases in water content leading to decreases in compression strength and elastic modulus, and increases in peak strain and energy dissipation. Acoustic emission energy decreases with water content, and sudden changes in signal characteristics can serve as precursors to rock destabilization and failure.
ENGINEERING GEOLOGY
(2021)
Article
Geochemistry & Geophysics
Hongru Li, Manchao He, Rongxi Shen, Yingming Xiao, Tai Cheng
Summary: The research findings suggest that increasing water content can decrease the frequency and intensity of AE signals during rock failure. Water has a greater impact on the intensity of AE signals than on the frequency. The analysis of the energy mechanism of rock failure indicates a close relationship between the frequency and intensity of AE signals with elastic energy index W-ET and burst energy index K-E, providing important insights for rockburst monitoring.
Article
Geosciences, Multidisciplinary
Hongru Li, Rongxi Shen, Yafei Qiao, Manchao He
Summary: The research focused on the mechanical properties and AE signal features of sandstone with varying water contents, revealing a critical slowing down phenomenon in the AE signals. The variance was found to be more sensitive to large-scale fracture of rock compared to autocorrelation coefficient, with less false signals, serving as an effective precursor for indicating rock failure. Sandstone samples with higher water content showed earlier and more notable precursor points.
JOURNAL OF APPLIED GEOPHYSICS
(2021)
Article
Engineering, Multidisciplinary
Hongru Li, Yafei Qiao, Rongxi Shen, Manchao He
Summary: This paper investigates the changes in electromagnetic radiation (EMR) signals of sandstone samples with different water contents and finds that water content has an impact on the signals. The experimental results show that with the increase of water content, the EMR signals of sandstone weaken, and the mechanical strength decreases. Through multifractal analysis, it is discovered that an increase in water content leads to a decrease in the non-uniformity of signals and frequency diversity, which can be considered as precursors of rock failure.
Review
Engineering, Geological
Manchao He, Tai Cheng, Yafei Qiao, Hongru Li
Summary: This article provides a comprehensive review of the recent developments and state-of-the-art in experimental, theoretical, and numerical approaches for investigating rockburst behavior and mechanisms. The definition and classification of rockburst are summarized, and available laboratory experimental technologies are reviewed. Key influencing factors and rockburst theories are discussed, as well as simulation approaches. The accuracy, stability, and reliability of different approaches are compared and assessed.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2023)
Article
Engineering, Geological
Jie Hu, Manchao He, Hongru Li, Tai Cheng, Zhigang Tao, Dongqiao Liu, Di Peng
Summary: Impact-induced rockburst hazards pose a severe threat to the construction safety of deep-buried, high-stress tunnels. This paper investigates the control effect of Negative Poisson's ratio (NPR) cable on impact-induced rockburst. Through indoor simulation experiments, it is found that the support of NPR cables enhances energy dissipation, rock fragmentation, and the strength of the rock. Importantly, NPR support significantly minimizes the rockburst intensity by slowing down the energy release rate during rock failure. The research results provide valuable guidance for the engineering practice of rockburst control.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Yingming Xiao, Manchao He, Yafei Qiao, Menglong Peng, Hongru Li, Tai Cheng
Summary: The nonlinearity of rock becomes more significant as the buried depth increases, affecting stress redistribution and deformation patterns during tunneling. A newly proposed UHS model and the finite difference method are used to obtain a semi-analytic solution that accurately calculates the plastic internal variable and stress state in the plastic zone, without stress vibration in the strain-hardening zone. The model is validated and the effects of strain-hardening, strain-softening, and prestress on ground reactions are highlighted.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Mechanics
Tai Cheng, Hongru Li, Manchao He, Yingming Xiao
Summary: In this study, a series of tests were conducted on sandstone specimens immersed in water for different durations, and the mechanical properties and acoustic emission (AE) characteristics were analyzed. The results showed that the uniaxial compressive strength and elastic modulus decreased, while Poisson's ratio increased with the passage of immersion time. The mechanical parameters exhibited exponential correlation with immersion time and linear correlation with water content. The dominant failure mode evolved from tensile failure to shear failure gradually, and the AE intensity and frequency weakened. The weakening in rock strength and AE signals were attributed to the transformation in micro-fracture form induced by the deterioration of grain cementation.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
Hongru Li, Manchao He, Yafei Qiao, Tai Cheng, Yingming Xiao, Zhoujie Gu
Summary: In this study, a series of mode I fracture tests were performed on NSCB sandstone specimens under coupled static-dynamic loading using SHPB. The purpose was to investigate the dynamic fracture properties and energy partitioning, which have important implications for understanding the rockburst mechanism and its kinetic energy source. The results showed that as the loading rate increases, various fracture parameters and energy dissipation increase, while the proportion of kinetic energy decreases. The effects of static pre-load on these behaviors were also analyzed.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
Zhuang Sun, Yixin Zhao, Yirui Gao, Sen Gao, Davide Elmo, Xindong Wei
Summary: In this study, the modified semi-circular bending test was used to investigate the fracture toughness of coal samples with different sizes and bedding angles. The results showed that the fracture toughness of coal exhibits size effect and anisotropy. The crack initiation and propagation in hydraulic fracturing of coal seam can be influenced by bedding angles.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Ruiming Zhang, Kai Ma, Wenzhu Peng, Jinyang Zheng
Summary: The fatigue crack growth rates of 4130X steel in different hydrogen concentrations were measured, and the influence of hydrogen on crack behavior was analyzed. Results show that the crack growth rate increases with increasing hydrogen pressure, reaching a threshold at 87.5 MPa.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Hien Do, Phuc L. H. Ho, Canh V. Le, H. Nguyen-Xuan
Summary: In this study, a new method for determining the limit loads of fracture structures using the pseudo-lower bound method with adaptive quadtree meshes is proposed. The method overcomes the volumetric locking problem and handles the challenge of hanging nodes during refinement procedure by using quadtree meshes. The effectiveness of the approach is demonstrated through numerical validation.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Weimin Song, Yuxin Fan, Hao Wu, Liang Zhou
Summary: This study proposed a novel test method to characterize the I-II mixed fracture toughness of asphalt pavement and investigated the effects of reclaimed asphalt pavement (RAP) and loading rate. The results showed that loading rate and inclusion of RAP had positive effects on fracture toughness.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Zida Liu, Diyuan Li, Jianqiang Xia, Quanqi Zhu
Summary: In this study, the influence of flaw inclinations on the failure mechanism of fissured granite specimens was analyzed through a series of experiments. A quantitative method combining deep learning and scanning electron microscope was employed to identify the mesoscopic fracture mechanism of macroscopic cracks. The results indicated that the failure of fissured specimens was mainly caused by tensile stress and shear stress.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Jiabing Zhang, Yiling Chen, Ronghuan Du, Xianglian Zhao, Jun Wu
Summary: This study investigated the mechanical characteristics and crack propagation behavior of sandstone-like samples with single cracks under freeze-thaw cycles. The results demonstrated the significant effects of crack angle and freeze-thaw cycles on the compressive strength and stability of the samples. Confining pressure inhibited the freeze-thaw deterioration, and the acoustic emission signals exhibited good consistency with the stress-strain curves. The simulation results matched well with the experimental results, and five crack propagation modes were proposed.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Felix Boedeker, Pauline Herr, Anders Biel, Ramin Moshfegh, Stephan Marzi
Summary: Cohesive Zone Models with finite thickness are widely used for fracture mechanical modeling. Computational homogenization techniques are crucial for the development of advanced engineering materials. FFT-based homogenization scheme shows potential in reducing computational effort and has practical applications.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Sobhan Pattajoshi, Sonalisa Ray, Yugal Kishor Joshi
Summary: In this work, a novel multi-layer composite structure is proposed for protective shelter design. The dynamic behavior and mechanical performance of the multi-layer composite under projectile impact loading are investigated. The proposed composite target demonstrates enhanced penetration resistance and lesser damage compared to its reinforced concrete monolayer counterpart. An analytical model is also developed to predict the forces transmitted to the lowest layer for design purposes.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
H. M. Shodja, M. T. Kamali, B. Shokrolahi-Zadeh
Summary: This study proposes a semi-analytical method for calculating the stress intensity factor of an internally pressurized eccentric annular crack. By using hypersingular integral equations and conformal mapping, accurate values of SIFs along the crack edges can be obtained. The material properties of the elastic matrix do not affect the SIF values, as demonstrated through the investigation of geometric parameters.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Wen Hua, Zhanyuan Zhu, Wenyu Zhang, Jianxiong Li, Jiuzhou Huang, Shiming Dong
Summary: Accurate assessment and prediction of fracture behavior in cracked materials using mixed mode fracture criteria are crucial in fracture mechanics. This study comprehensively reviewed modified fracture criteria that incorporate T-stress for mixed mode I-II cracks. A comparative analysis was conducted between experimental results and theoretical predictions for five different cracked configurations. The study also discussed the effect of T-stress on crack initiation angle and fracture toughness, providing suggestions. The results showed variations in predictive accuracy across different cracked configurations due to disparities in T-stress. However, similar predictions were observed for semi-circular bend and edge-crack triangular specimens due to their similar biaxial stress ratio B. Different fracture criteria were suitable for different cracked configurations with positive or negative T-stresses.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Qing-qing Shen, Qiu-hua Rao, Wei Yi, Dian-yi Huang
Summary: This study proposes a theoretical approach to forecast multi-crack propagation trajectories in a finite plate. By calculating the stress intensity factor (SIF) and analyzing the influence of crack size, the criteria for crack initiation and propagation in a finite plate are established. Experimental results demonstrate that the SIF of multiple cracks in a finite plate is consistently larger than that of an infinite plate.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Songbai Li, Qiyun Zhu, Zhizhong Lu, Hongzhi Yan, Chu Zhu, Peize Li
Summary: This study investigates the effects of laser heating and laser shot peening on fatigue life of AA2524, and predicts the fatigue life using artificial neural networks and support vector regression models. The results show that laser heating and laser shot peening can significantly improve the fatigue life, and the neural networks have better prediction ability.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
V. Shlyannikov, A. Sulamanidze, D. Kosov
Summary: This paper presents experimental crack-growth data for thermomechanical fatigue conditions in nickel-based alloy components. The crack-growth experimental results are interpreted using finite element analyses and multi-physics numerical calculations. The results show that crack growth rate is slower under isothermal pure fatigue conditions, while it is faster under thermomechanical cyclic deformation conditions.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Tairui Zhang, Xin Ma, Bin Yang, Wenchun Jiang, Zhiqiang Ge, Xiaochao Liu
Summary: This study experimentally investigated the fracture toughness distributions in dissimilar metal welds. The predictions of fracture toughness were made using three criteria and an energy release rate model. The results showed that using the critical strain criterion and ERR model resulted in higher consistency compared to mini-CTs, while the predictions using the critical stress criterion had high dispersion. The study also investigated the source of errors through damage developments and SEM observations.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)
Article
Engineering, Mechanical
Yike Dang, Zheng Yang, Xiaoyu Liu, Jianghao Guo
Summary: This study uses discrete element modeling to examine bedded rock failure with parallel defects. It is found that bedding influences crack propagation direction but has limited impact on final failure. Shear failure accumulates at the bridge area and defect tip, while tensile failure occurs during nucleation region development.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2024)