Article
Construction & Building Technology
Xinwu Zhou, Sho Takeda, Tetsuya Uchimoto, Mitsuo Hashimoto, Toshiyuki Takagi
Summary: An EPAT method was investigated for evaluating debonding between rebar and concrete. Debonding specimens were prepared by wrapping polystyrene foam around a rebar. Elastic wave signals were collected using an acoustic emission sensor. EPAT was demonstrated to be useful for non-destructive evaluation of debonding by comparing the differences in signal reach time between specimens with and without debonding. Finite element simulations also validated the reliability of EPAT for examining debonding in reinforced concrete.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Polymer Science
Milan Ferdinand, Robert Vardai, Janos Moczo, Bela Pukanszky
Summary: Acoustic emission is a commonly used method for studying local deformation processes in heterogeneous polymer systems, providing valuable information about possible deformation mechanisms through the analysis of wave parameters. The number of signals generated in acoustic emission testing of composites can vary greatly due to factors such as particle size, interfacial adhesion, and composition.
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
Materials Science, Ceramics
A. Abaza, J. Laurencin, A. Nakajo, M. Hubert, T. David, F. Monaco, C. Lenser, S. Meille
Summary: Micro-compression tests were conducted on plasma focused ion beam milled pillars in porous YSZ pellets. The results showed that the mechanical properties were reproducible due to the homogeneity of the microstructures. The compressive fracture strength was found to decrease with increasing porosity, and a transition from brittle behavior to diffuse damage was observed.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Engineering, Mechanical
H. Salimi-Mofrad, A. Rahbar Ranji, H. Saghafi
Summary: In this research, the fracture toughness of composite laminates was improved by embedding polyamide 66 nanofibers between the layers. The results showed that adding nanofibers of specific thicknesses significantly increased the fracture toughness in Mode-II loading. Acoustic emission method and SEM micrographs were used to examine the key features and failure mechanisms.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Construction & Building Technology
Wengang Hu, Jilei Zhang
Summary: This study investigates the effects of growth rings on acoustic emission (AE) characteristic signals in southern yellow pine (SYP) wood. Results show that crack tip locations significantly affect AE counts and energy, but not amplitude. AE counts and energy are higher in earlywood compared to the early-latewood interface and latewood. These distinct AE characteristic signals can be used for crack detection in wooden structures.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Energy & Fuels
Mengchao Yi, Fachao Jiang, Languang Lu, Jianqiao Ren, Mingxin Jin, Yuebo Yuan, Yong Xiang, Xiaofeng Geng, Xingong Zhang, Xuebing Han, Minggao Ouyang
Summary: This study proposed a method of in situ testing of batteries using ultrasound, and analyzed the acoustic energy to evaluate the state of the active material. The results showed a high correlation between acoustic energy and the calculated acoustic impedance of the active material, indicating that ultrasound is an effective method for studying the status of Li-ion batteries.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Engineering, Environmental
Feng Ju, Dong Wang, Zhongwei Wang, Meng Xiao, Zequan He, Pai Ning, Tengfei Wang, Li Li, Chaoseng Yan, Tao Zhou
Summary: This paper investigates the influence of joint dip angle on coal strength through experimental research. It reveals that coal samples with different joint dip angles exhibit anisotropic mechanical properties and acoustic emission (AE) characteristics. Coal pillars with a joint dip angle close to 60 degrees are most likely to experience shear failure and instability, highlighting the importance of reinforcement measures for mining production safety.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2023)
Article
Chemistry, Physical
Ling Fan, Chengbo Wang, Di Hu
Summary: Rock masses are inherently heterogeneous and contain fractures that affect their mechanical properties, fracture characteristics, and acoustic emission features. Microbially induced calcite precipitation (MICP) technology can repair fractured rock masses. In this study, uniaxial compression tests were conducted on sandstone samples with prefabricated fractures, and the effects of MICP repair were analyzed. The results showed improved properties and mitigated failure process in the filled specimens. The study provides a theoretical basis and experimental evidence for repairing rock fractures using MICP technology.
Article
Engineering, Multidisciplinary
Michal Kunicki
Summary: This paper presents an analysis of the variability of acoustic emission (AE) signals generated by prolonged partial discharges (PD) under AC voltage. The objective is to indicate the variability of AE signals and propose alternative feature extraction methods. Three scenarios based on different solid dielectric materials are investigated and compared, and three feature extraction methods are proposed and analyzed. The results extend the current state of the art in AE measurements of PD and have potential application in PD denoising, classification, and localization.
Article
Green & Sustainable Science & Technology
Fujiang Wang, Liyun Fan, Yihu Chen, Zhaohua Wan, Fabiao Liu
Summary: Uniaxial compression tests were conducted using acoustic emission technology to investigate the damage evolution process of marble powder concrete (MPC) under compression. The analysis of acoustic emission signal parameters revealed the fracture characteristics of MPC. The results showed that the strength loss rate of MPC decreased with curing time, and the compression failure process could be divided into three stages. The percentage of tensile mode cracks decreased in stages I and II but increased in stage III, indicating a transition from brittleness to ductility. The fluctuation amplitude of the b-value also increased with the substitution percentage. The damage development of MPC was slower in the middle stress stage and accelerated in the late stress stage when the substitution percentage was less than 15%.
Article
Mechanics
Johannes Reiner, Jake Wood, Mahbube Subhani
Summary: ENF and CS tests were conducted to evaluate Mode II fracture properties in wood using Australian Radiata Pine. The capabilities and limitations of each test were compared in terms of testing convenience, reduction schemes for determining Mode II fracture toughness or strain-energy release rate, stable crack growth, and mixed mode behavior. Results showed that ENF tests provide stable and reliable Mode II fracture with minimal mixed-mode behavior, unlike CS tests. Crack length measurements were only necessary to determine initial fracture energy values associated with crack lengths up to 20 mm, while compliance-based beam theory was used to calculate steady-state fracture energies using an equivalent crack length derived from global load-displacement test data.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Mechanics
Qiquan Xiong, Qing Lin, Yue Gao, Jesse C. Hampton
Summary: This study resolves a misunderstanding in the general observation of AE releases from mode-I and mixed-mode fracture toughness tests and compression tests on rock core or prismatic blocks. It investigates the detailed AE energy release organization from two novel approaches, revealing that the two types of rock fracture processes are of different physical processes. The scaling features of the AE releases suggest the observational features for a notch-induced rock fracture process are universal across scale.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Mining & Mineral Processing
Dongjie Xue, Zepeng Zhang, Cheng Chen, Jie Zhou, Lan Lu, Xiaotong Sun, Yintong Liu
Summary: The cube-cluster model effectively describes the spatial correlation of scattering AE events in a granite sample under triaxial compression, allowing for the analysis of fracture network and quantitative evaluation of fracture angle evolution. Additionally, it provides a potential possibility to predict the evolution of fracture angle.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Geological
Wei Zhang, Baoliang Zhang, Tongbin Zhao
Summary: Studying the characteristics of acoustic-thermal signals in the failure process of weakly cemented fractured rocks is of great significance for expanding the analysis methods of rock fracture laws. Biaxial compression tests were conducted on weakly cemented sandstone samples to investigate the evolution law of acoustic-thermal signals. The joint analysis index of acoustic-thermal sensitivity was proposed and the research results showed different sensitivities and sequences of the joint index for fractured rocks with different dip angles.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Chemistry, Analytical
Spyridoula Farmaki, Dimitrios A. Exarchos, Ilias K. Tragazikis, Theodore E. Matikas, Konstantinos G. Dassios
Article
Chemistry, Physical
Panagiota Alafogianni, Konstantinos Dassios, Christos D. Tsakiroglou, Theodore E. Matikas, Nektaria-Marianthi Barkoula
Article
Chemistry, Analytical
Panagiota T. Dalla, Ilias K. Tragazikis, George Trakakis, Costas Galiotis, Konstantinos G. Dassios, Theodore E. Matikas
Summary: Recent findings suggest that carbon nano-species, such as nanotubes and graphene, have the potential to improve the multifunctional properties of cement, including mechanical, fracture mechanical, and electrical properties. Testing on mortars modified with graphene nanoplatelets and carbon nanotubes showed significant improvements in fracture behavior at specific nanofiller concentrations, indicating great potential for smart construction applications.
Article
Chemistry, Multidisciplinary
Ilias K. Tragazikis, Theodoti Z. Kordatou, Dimitrios A. Exarchos, Panagiota T. Dalla, Theodore E. Matikas
Summary: There is a growing need to understand the relationship between construction material properties and behavior with their microstructure, especially in the context of freshly poured cement-based materials. This study focuses on developing a reliable method for monitoring the hydration process in cementitious composites enhanced with carbon nanotubes, utilizing a combination of nonlinear elastic waves, contact ultrasonics, and noncontact optical detection. Changes in material nonlinearity during the hardening process, particularly with increased carbon nanotube concentration, can be detected through the assessment of higher-harmonic amplitudes of an ultrasonic wave, providing valuable insights for structural behavior in the long term.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Elias Ananiadis, Konstantinos T. Argyris, Theodore E. Matikas, Athanasios K. Sfikas, Alexandros E. Karantzalis
Summary: Novel aluminium matrix composites reinforced by MoTaNbVW refractory high-entropy alloy (HEA) particulates were fabricated by powder metallurgy. The composites exhibited low porosity, good homogeneity, few defects, and good distribution of the reinforcing phase in the Al matrix. However, increasing the volume of the reinforcing phase led to increased hardness values, while the Al-HEA composites showed susceptibility to localised forms of corrosion in 3.5% NaCl solution.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Janardhan Padiyar M., Luca Zanotti Fragonara, Ivan Petrunin, Joao Raposo, Antonios Tsourdos, Iain Gray, Spyridoyla Farmaki, Dimitrios Exarchos, Theodore E. Matikas, Konstantinos G. Dassios
Summary: A new method for detecting damage in aircraft composite materials has been developed in this study, utilizing phased-array ultrasonics and infra-red thermography techniques, and achieving satisfactory results on aircraft-grade painted composite materials. The sensor systems have been miniaturized for integration onto a vortex-robotic platform inspector as part of the larger research project, the Horizon-2020 'CompInnova' project.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Anastasios C. Mpalaskas, Theodore E. Matikas, Dimitrios G. Aggelis, Ninel Alver
Summary: The enhancement of ductility and toughness in steel fiber reinforced concrete is attributed to additional fracture mechanisms and overcoming interlocking and adhesion between fibers and the cementitious matrix. Acoustic emission monitoring can provide real-time characterization of material performance, and low load levels of AE behavior are indicative of reinforcement and final mechanical properties.
APPLIED SCIENCES-BASEL
(2021)
Proceedings Paper
Engineering, Multidisciplinary
I. K. Tragazikis, T. Z. Kordatou, P. T. Dalla, D. A. Exarchos, T. E. Matikas
Summary: The behavior and properties of construction materials depend largely on their internal microstructure characteristics. Understanding the curing process of freshly poured cementitious materials is crucial for successful construction development. Changes in ultrasonic wave propagation and pulse velocity occur during the solidification of cement-based materials, with the point of solidification affecting load-bearing capacity and long-term behavior.
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2021
(2021)
Proceedings Paper
Engineering, Multidisciplinary
A. C. Mpalaskas, D. G. Aggelis, T. E. Matikas
Summary: This study conducted fracture experiments on fiber reinforced concrete beams to examine the level of restoration using acoustic emission (AE) technique. The specimens were repaired with epoxy resin injection to main macrocracks, showing good insight of microstructure and restoration level.
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2021
(2021)
Proceedings Paper
Engineering, Multidisciplinary
A. C. Mpalaskas, D. G. Aggelis, T. E. Matikas
Summary: This study examines the fracture behavior of mortar specimens modified with waterproofing adhesives using acoustic emission (AE). The results suggest that the use of adhesives in mortars can be successfully characterized by AE and ultrasonic parameters, indicating the value of elastic wave nondestructive evaluation in the building materials sector.
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2021
(2021)
Proceedings Paper
Engineering, Multidisciplinary
P. T. Dalla, I. K. Tragazikis, D. A. Exarchos, T. E. Matikas
Summary: The study aims to investigate the impact of graphene nanoplatelets on the mechanical and electrical properties of cement mortars. Significant improvements in mechanical characteristics and fracture energy were observed at specific graphene loadings, as evaluated by acoustic emission data. Additionally, the electrical response of the graphene-modified cement mortars was studied through electrical conductivity measurements.
SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2021
(2021)
Proceedings Paper
Computer Science, Interdisciplinary Applications
A. C. Mpalaskas, D. G. Aggelis, T. E. Matikas
SMART STRUCTURES AND NDE FOR INDUSTRY 4.0, SMART CITIES, AND ENERGY SYSTEMS
(2020)
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)
