Article
Construction & Building Technology
Kai Liu, Chengqing Wu, Xibing Li, Ming Tao, Jun Li, Jian Liu, Shenchun Xu
Summary: This study investigates the behavior of ultra-high performance concrete (UHPC) under coupled axial static and impact loading in the presence of fire damage. The results show that fire damage significantly degrades the mechanical properties of UHPC, and axial static compression can enhance the dynamic mechanical properties in the elastic phase but weaken them in the plastic phase. The dynamic increase factor increases with temperature, and UHPC loses most of its strength at temperatures of 500 and 750 degrees C.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Mechanics
Zelin Liu, Chunde Ma, Xin'ao Wei, Weibin Xie
Summary: The presence of cracks had a weak effect on the strength of sandstone specimens during direct tensile testing (DTT) and uniaxial compression testing (UCT). However, the strengths of the specimens increased gradually with different crack inclinations (fi). The elastic modulus of rock increased with an increase in fi during UCT, while it remained almost unchanged during DTT.
ENGINEERING FRACTURE MECHANICS
(2021)
Review
Engineering, Geological
Liwang Liu, Haibo Li, Xiaofeng Li
Summary: The mechanical properties and failure behavior of rocks with flaws or discontinuities have been extensively studied in the field of rock mechanics. This paper provides a systematic review of experimental results on pre-cracked rocks under quasi-static compression. The influence of flaw geometries, filling conditions, and confining pressure on the mechanical characteristics of rocks is discussed. The cracking process is evaluated in terms of crack initiation, coalescence, and failure patterns.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2022)
Article
Engineering, Geological
Zelin Yan, Feng Dai, Jianbo Zhu, Yuan Xu
Summary: This study systematically investigated the influences of pre-stress ratio, flaw inclination angle, and strain rate on the dynamic progressive cracking mechanism and energy evolution of multi-flawed rocks. The experimental results show that the dynamic/total strength generally increases with increasing strain rate, decreases with increasing flaw inclination angle, and exhibits complex changes with increasing pre-stress ratio.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Geological
Kai Wang, Guorui Feng, Jinwen Bai, Jun Guo, Xudong Shi, Boqiang Cui, Cheng Song
Summary: In this study, the mechanical behavior of coal under the coupled action of water pressure, static load, and impact load was investigated. The results showed that water pressure positively affected the dynamic strength and energy utilization efficiency of the coal samples.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Engineering, Geological
Jinyin Ma, Diyuan Li, Pingkuang Luo, Chenxi Zhang, Feihong Gao
Summary: The influence of bedding angles and pre-static loads on dynamic mechanical properties and damage mechanisms of layered sandstone under cyclic impact loads was investigated through a series of cyclic impact tests. It was found that the number of resisting cyclic impacts and the total dissipated energy of the sandstone showed an initial decline followed by an increase with the rising of the bedding angles. The damage evolution of the sandstone under cyclic impacts was described using a damage factor and the impact time curves could be divided into three stages. The damage threshold decreased as the pre-static load increased.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
Feng Dai, Qi Zhang, Yi Liu, Hongbo Du, Zelin Yan
Summary: This study investigates the influence of cyclic coupled compression-shear loading on the fatigue mechanical response of inclined sandstone specimens. The testing results reveal the deformation characteristics, energy evolution, damage variable, and failure mechanism under different loading conditions. A fatigue life prediction method based on energy dissipation is proposed and validated against experimental results. The cracking behavior of rocks during fatigue tests is analyzed using digital image correlation technique.
Article
Engineering, Mechanical
Yu Wu, Dongdong Ma, Xunjian Hu, Yang Hao, Chunhui Liu, Haiyang Zhou
Summary: This study investigates the fracture behavior of bedding argillaceous sandstone models with pre-existing flaws through simulated experiments. The results show that an increase in included angle and loading rate leads to an increase in peak strength and a decrease in the angle of the main fracture plane. The variation of peak strength and b-value decreases with the bottom flaw length, with smaller tensile acoustic emission (AE) event and larger shear AE event for interlayer and bedding cracking, respectively. Loading rate promotes the change of AE event from tensile to shear mode with a wider fracture plane. The research results could contribute to improving safe production at coal mine workings.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Geochemistry & Geophysics
Fei Xue, Tongyang Zhao, Xiaowei Feng, Tianzuo Wang, Zhongqin Lin
Summary: This study investigates the influence of bedding structure on the mechanical properties and failure mechanism of anisotropic rocks. The results show that the peak strength of stratified sandstone exhibits an obvious anisotropic characteristic with increasing bedding orientation. The use of acoustic emission and digital image correlation helps analyze the mechanism of crack initiation and propagation. Furthermore, the stages of crack closure and linear elastic deformation vary significantly with different bedding orientations.
Article
Engineering, Geological
Chuan-Gen Gong, Wei Wang, Jian-Fu Shao, Ru-Bin Wang, Xiao-Wei Feng
Summary: The study investigates the effects of chemical corrosion on mechanical properties of pre-fissured red sandstone samples. Cylinder samples with single fissures are immersed in different chemical solutions and filled with gypsum. Uniaxial compression tests are conducted to analyze the changes in elastic properties and compression strength, as well as cracking patterns during the tests.
Article
Materials Science, Multidisciplinary
Peng Feng, Feng Dai, Kewei Shuai, Mingdong Wei
Summary: The static and dynamic mechanical behaviors of sandstone with noncoplanar and unparallel flaws were systematically investigated in this study. It was demonstrated that the strength, fractal characteristics, and energy dissipation of the pre-fractured sandstone showed a dependence on loading rate. The dynamic strength of unparallel-flawed sandstones was found to be more sensitive to strain rate compared to that of noncoplanar-flawed sandstones. The failure modes of the specimens were primarily controlled by tensile cracks under static compression, while shear cracks had a greater effect on the dynamic failure patterns. Under low dynamic strain rates, the specimens mainly broke into columnar or lamellar structures with a significantly non-uniform size distribution and relatively small amount of energy dissipation. At high dynamic strain rates, the flawed rocks experienced severe damage and broke into many small fragments with relatively uniform sizes, accompanied by comparably high energy dissipation.
MECHANICS OF MATERIALS
(2022)
Article
Engineering, Geological
Chenxi Zhang, Diyuan Li, Jinyin Ma, Quanqi Zhu, Pingkuang Luo, Yuda Chen, Minggang Han
Summary: Investigating the dynamic shear fracture behavior of rocks under simulated geostress is crucial for deep rock engineering. Four groups of dynamic mode II fracture tests were conducted on granite specimens with different axial pre-forces using a coupled static-dynamic loading system. The results showed that the dynamic mode II fracture toughness increases with loading rate and decreases with pre-force ratio. An empirical model was established to describe the influence of pre-force and loading rate on fracture toughness. Deformation, damage, and fracture characteristics of rocks were analyzed based on surface deformation field. The study also proposed a novel relative shear velocity (RSV) to depict dynamic shear crack propagation.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Geochemistry & Geophysics
Xiang Li, Si Huang, Tubing Yin, Xibing Li, Kang Peng, Xiaodong Fan
Summary: In this study, the influence of thermal shock on the mechanical behaviors of rock was investigated by conducting heating experiments on sandstone specimens at different temperatures and utilizing three cooling methods with different cooling rates. The results were analyzed based on dynamic compressive strength, energy dissipations, and fracturing characteristics. The findings provide valuable insights for rock engineering practices involving high temperatures and fast cooling.
Article
Mathematics
Pin Wang, Tubing Yin, Xibing Li, Heinz Konietzky
Summary: Microwave irradiation on rocks can effectively reduce equipment wear and energy consumption during mechanical cutting. The increase in water content improves the microwave heating capacity of the rock and leads to a decrease in weight, P-wave velocity, and tensile strength, as well as an increase in porosity and damage factor.
Article
Engineering, Civil
Yipeng Chang, Weidong Wen, Yiming Xu, Haitao Cui, Ying Xu
Summary: This paper presents an experimental study on the mechanical behavior of filament wound carbon fiber reinforced polymer under different loading conditions. The results show that the material exhibits non-linear damage progression under tensile load, brittle failure under pure torsional load, and progressive damage with lower failure strength under tension-torsional load compared to pure tension or torsion load conditions.
THIN-WALLED STRUCTURES
(2022)
Article
Chemistry, Analytical
Zilong Zhou, Riyan Lan, Yichao Rui, Longjun Dong, Xin Cai
Summary: A new algebraic solution for AE source localization without premeasuring wave velocity is proposed, improving the positioning accuracy by more than 40% with a minimum accuracy of 1.12 mm. Experimental validation and simulation tests demonstrate the effectiveness of the proposed method under different TDOA errors and sensor numbers.
Article
Geochemistry & Geophysics
Zilong Zhou, Boxiang Lei, Xin Cai, Yichao Rui
Summary: An upscaling method for estimating macrofracture toughness by nanoindentation results was proposed and verified in this study. Grid nanoindentation tests were conducted on sandstone samples to obtain micromechanical properties, and the method resulted in a discrepancy of 8.8% compared to the NSCB test, proving its accuracy and reliability in providing more precise upscaling results.
Article
Engineering, Civil
Xin Cai, Chuanqing Cheng, Yuan Zhao, Zilong Zhou, Shaofeng Wang
Summary: This study investigated the coupled effects of water content and loading rate on the dynamic tensile strength of rocks. Experimental results showed that the dynamic tensile strength of sandstone is positively sensitive to loading rate, and this rate dependence increases as the water content rises. The change trends of tensile strength against water content were found to depend on the loading rate, with a no change followed by a fast drop observed at low loading rates and an increase followed by a decline observed at high loading rates.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2022)
Article
Engineering, Mechanical
Lihai Tan, Ting Ren, Linming Dou, Xiaohan Yang, Xin Cai, Ming Qiao
Summary: The study demonstrates that the accuracy of stress solution for plates containing holes with corners is improved by optimizing the Schwarz alternating method without inverse mapping function. Through simulation experiments, it was found that hoop stress linearly relates to lateral pressure coefficient and fractures tend to initiate around boundaries where stress concentrates.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Materials Science, Multidisciplinary
Zhaohui Lu, Yunzhong Jia, Jiankun Zhou, Pei He, Menglai Li, Zhengyang Song, Xin Cai
Summary: This research investigates the evolution of shale fracture permeability after interactions with supercritical carbon dioxide (Sc-CO2). The results show that soaking with Sc-CO2 dramatically increases the shale fracture permeability and aperture due to the dissolution of calcite and dolomite. This process may last for seven days, after which the rock-Sc-CO2 system becomes stable.
ADVANCES IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Zhengyang Song, Yunfeng Wu, Zhen Yang, Xin Cai, Yunzhong Jia, Min Zhang
Summary: This study investigates the mechanical responses of deeply seated granite samples through uni/triaxial cyclic tests, highlighting disparities in strain evolution and compressive strength under different loading conditions, as well as the relationships between deformation behavior, dissipated energy, and hysteresis. It also reveals quantitative correlations between strain evolution and cyclic stress levels, determines energy transformation during cyclic loading, and discusses the impacts of confining pressure level on ultimate strain, energy dissipation, and stress-strain phase shift. The mechanical responses of the granite samples subjected to different stress paths and loading strategies are summarized and explained to clarify the discrepancies in mechanical behavior encountered in distinct loading methods.
ADVANCES IN MATERIALS SCIENCE AND ENGINEERING
(2021)
Article
Mining & Mineral Processing
Yichao Rui, Zilong Zhou, Jianyou Lu, Barkat Ullah, Xin Cai
Summary: This paper proposes a novel acoustic emission (AE) source localization method using clustering detection to eliminate abnormal arrivals, which achieves higher localization accuracy and robustness. Experimental results and simulation tests demonstrate the effectiveness of the proposed method.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2022)
Article
Construction & Building Technology
Zilong Zhou, Jianyou Lu, Xin Cai, Yichao Rui, Lihai Tan
Summary: This study investigates the effects of water saturation and dip angle on the mechanical performance and failure characteristics of the rock-concrete interface. The results show that the peak load of the sample decreases after water saturation, regardless of the dip angle. The reduction of peak load is the most dramatic at a 15-degree dip angle. The weakening of water on the bearing capacity of the rock-concrete structure is most obvious at a theta angle of 18.43 degrees.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Multidisciplinary
Yichao Rui, Zilong Zhou, Xin Cai, Longjun Dong
Summary: In this paper, a robust method for acoustic emission source location is proposed using the DBSCAN principle. The method calculates source coordinates and clusters them to improve location accuracy, and the results show its effectiveness and robustness.
Article
Engineering, Multidisciplinary
Lihai Tan, Zilong Zhou, Xin Cai, Yichao Rui
Summary: This study investigates the mechanical properties and fracture behavior of rock containing multiple cavities. Experimental and numerical methods are used to analyze the stress evolution and failure coalescence patterns influenced by cavity layout.
Article
Mathematics
Yuan Zhao, Guoyan Zhao, Jing Zhou, Xin Cai, Ju Ma
Summary: This study proposes a method for determining the parameters of the brittle-ductile transition model in inclined backfilled stopes and establishes a model to simulate the mining process of ore bodies with varying depths. The results show that mining-induced stress will transfer to upper stopes and the stratum below the deepest stope, and the range and influence of mining-induced stress will increase with deep mining.
Editorial Material
Mathematics
Shaofeng Wang, Xin Cai, Jian Zhou, Zhengyang Song, Xiaofeng Li
Editorial Material
Mathematics
Linqi Huang, Shaofeng Wang, Xin Cai, Zhengyang Song
Article
Chemistry, Physical
Xin Cai, Jifeng Yuan, Zilong Zhou, Zhibo Wu, Jianmin Liu, Barkat Ullah, Shaofeng Wang
Summary: A series of cyclic point load (CPL) tests were conducted on sandstone samples using a self-developed vibration point-load apparatus to investigate the fatigue behavior of rock materials under CPL conditions. The effects of loading frequency and waveform on the fatigue properties of sandstone were specifically studied. The results showed that the fatigue life of the sandstone sample under CPL was influenced by both loading frequency and waveform. The findings can provide valuable theoretical support for optimizing rock cutting parameters in mechanized excavation.
Article
Mathematics
Zilong Zhou, Hang Yuan, Xin Cai
Summary: This paper proposes a new pooling mode to enhance the ability of CNN to represent rock feature information and improve rock identification performance. The pooling layers are divided into the sampling pooling layer and the classification pooling layer based on whether the pooling object is the last convolution layer. The adaptive pooling method is used in the sampling pooling layer, and the second-order pooling method is used in the classification pooling layer. The ASOPCNN model built with these methods achieves the highest identification accuracy and outperforms other models in precision, recall, F1 score, and AUC values.
