Article
Engineering, Mechanical
Mingyang Teng, Jing Bi, Yu Zhao, Chaolin Wang
Summary: This study proposes a method for making rock-like samples containing embedded 3D flaws, and conducts a series of shear tests under different normal stresses. The test results show that the complex shear stress-shear displacement curve can be divided into four stages. The shear strength, residual strength, and shear modulus of the specimens are affected by the flaw dip angle and normal stress. Tensile failure is more likely to occur in low stress and small flaw angle specimens, while shear failure mainly occurs in high stress specimens. A sudden increase in AE counts, AE event rates, and a sudden decrease in b-value are usually precursors to rock failure. The RA/AF value can accurately reflect the classification and development of rock tension shear cracks. Damage locations of rock-like specimens in each stage are effectively identified through Kernel density estimation (KDE) analysis on the distribution of AE events. The movement of the maximum density point is consistent with the tendency of rock crack propagation, almost following the uniform diffusion of the specimens from the middle to the end.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Chemistry, Analytical
Ilaria Di Luch, Maddalena Ferrario, Davide Fumagalli, Michele Carboni, Mario Martinelli
Summary: This study presents a coherent optical fiber sensor with adequate sensitivity for detecting the acoustic emission during the propagation of a crack in a ferrous material. The sensor is compared to commercially available AE piezo-transducers sensors in terms of SNR and detectable AE energy levels, showing it to be an effective and advantageous alternative for sensing and monitoring fatigue damage in structural applications.
Article
Engineering, Mechanical
Jie Chen, Yabo Ye, Yuanyuan Pu, Wenhan Xu, Deren Mengli
Summary: Water content and fissure angles have significant effects on the slope stability in open-pit mining. This study investigates the influence of water and fissures on rock strength, failure modes, and acoustic emission characteristics through experiments and monitoring. The findings provide theoretical foundations for monitoring and pre-warning of engineering rock failure in water environments.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Sijia Liu, Zaiquan Wang, Yongjun Zhang, Miaomiao Kou, Jing Bi
Summary: In this study, a new explicit phase-field model with mixed-mode fracture driving forces is developed to simulate blasting fracture in granites. The model is able to accurately capture various fracture modes in rock materials. The correctness and accuracy of the model are validated through qualitative and quantitative comparisons with benchmarked examples and laboratory experiments. The model is then used to simulate a series of borehole blasting tests, allowing for investigations on the effects of blast loading parameters and mineral components on the dynamic failure characteristics of granites. This study provides a useful computational tool for researchers in rock mechanics and offers insights on dynamic rock fracture to engineers in rock engineering.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Materials Science, Ceramics
B. Swaminathan, N. R. McCarthy, A. S. Almansour, K. Sevener, A. K. Musaffar, T. M. Pollock, J. D. Kiser, S. Daly
Summary: The relationship between acoustic emission (AE) and damage source areas in SiC/SiC minicomposites was modeled using insights from in-situ tensile testing in scanning electron microscope (SEM). Damage up to matrix crack saturation was bounded by AE generated by matrix cracking (lower bound) and AE generated by matrix cracking, fiber debonding, and sliding in crack wakes (upper bound). Despite fiber debonding and sliding exhibiting lower strain energy release rates compared to matrix cracking and fiber breakage, they still contribute significantly to damage area and likely produce AE.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Construction & Building Technology
Yan Chen, Jiangfan Yang, Meiheng Li, Lei Zhou, Baohua Guo, Jianping Zuo
Summary: In this paper, laboratory direct shear tests and acoustic emission tests are conducted to analyze the shear properties of bonded rock-concrete interfaces. The results show that increasing roughness enhances brittleness and peak dilatancy characteristics, but the residual shear strength exhibits the opposite trend. The AE tests demonstrate the occurrence of peak AE energy and count generation during shear failure, and the evolution of the AE-b value indicates the repeated conversion between large and small-scale micro-cracks.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Thermodynamics
Rui Ding, Qiang Sun, Shengze Xue, Qingmin Shi, Zhenlong Ge, Delu Li
Summary: This paper investigates the development and evolution of cracks in the process of underground coal gasification using acoustic emission (AE) technique. The experiments were conducted on long flame coal samples heated to different temperatures in an oxygen-rich environment. The results show that the heating process can be divided into two stages based on AE counts, energy, and mass loss. The width of cracks on the surface of the coal samples gradually varies with the increase in heating temperature, becoming narrower at 500 degrees C due to tar condensation sealing the pores.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Engineering, Marine
Qin Dong, Geng Xu, Yaoyu Hu, Ziya Peng
Summary: The main objective of this paper is to investigate the residual strength of a cracked plate considering fatigue crack propagation under cyclic loading. Factors such as crack length, number of cycles, tensile/compressive cyclic loads, and out-of-plane deformation are considered in the study of residual strength. The numerical results provide insight into the effect of crack propagation on structural residual strength, aiming to guide the evaluation of residual strength in cracked components.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Geological
Yanlong Zheng, Zhongjun Ma, Qiuming Gong, Penghai Zhang, Xiaobao Zhao, Jianchun Li
Summary: Microwave fracturing of hard rocks shows promise, with heating playing a dominant role in the initiation and propagation of cracks, while the contribution of cooling can be neglected. The cracks initiate from the exterior of the antenna and propagate towards the interior of the specimens.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Energy & Fuels
Kai Si, Zhendong Cui, Ruidong Peng, Leilei Zhao
Summary: This study summarized the factors affecting rock fatigue life and investigated the fatigue damage process of rock from a microscopic perspective. A mesoscopic model considering wing crack propagation was introduced to examine the fatigue failure of sandstone, and a fatigue life prediction formula was derived. Acoustic emission signals were monitored and analyzed to distinguish tensile or shear properties of mesoscopic failure in different stages of fatigue crack propagation.
Article
Mechanics
Y. Wang, J. Q. Han, Z. Y. Song, C. Zhu
Summary: The study reveals that communication between the crack network and holes controls the volumetric deformation and final failure modes of the rock. Rock with low flaw angle shows more severe progressive crack unstable propagation. The b value of AE activities exhibits a specific pattern of increase and decrease.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Construction & Building Technology
Shengli Li, Longguan Zhang, Pan Guo, Pu Zhang, Chao Wang, Wencong Sun, Shanling Han
Summary: Ultra high performance concrete (UHPC) demonstrates superior mechanical properties and durability compared to normal concrete (NC) materials. The use of acoustic emission (AE) technique in monitoring crack propagation in UHPC-NC composite beams has shown promising results, with AE parameters exhibiting distinguishable characteristics at different failure stages. AE monitoring method can be considered as an alternative to traditional monitoring methods for real-time monitoring of crack propagation in UHPC-NC composite beams.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Yue Zhang, Jianfeng Shi, Jinyang Zheng
Summary: The study proposes a method combining acoustic emission and digital image correlation techniques to measure the fracture toughness of polyethylene pipe material, and verifies the effectiveness and accuracy of this method through numerical simulation and experimental testing.
MATERIALS & DESIGN
(2021)
Article
Geochemistry & Geophysics
Xu Chang, Faning Dang, Jiacheng Peng
Summary: In this study, a plastic-damaged model is used to simulate the cracking behavior of limestone containing a single filled fissure under cyclic compression. The results show that filled fissures can delay the initiation of cracks and increase the strength of specimens.
PURE AND APPLIED GEOPHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Vera Barat, Artem Marchenkov, Sergey Ushanov, Vladimir Bardakov, Sergey Elizarov
Summary: This paper is devoted to studying the possibility of using the acoustic emission (AE) method to detect cracks in railway rails. An experimental study of AE signals was conducted during cyclic compression loading of rail fragments. It was found that rail fragments with cracks generate higher activity AE signals compared to defect-free specimens. The presence of cracks leads to an increase in AE hits rate and changes in the distribution of AE hits amplitudes. The study also proposes criteria for crack detection by AE testing.
APPLIED SCIENCES-BASEL
(2022)