Article
Chemistry, Multidisciplinary
Pengcheng Liu, Jun Liu, Song Gao, Yue Wang, Haowen Zheng, Mengyang Zhen, Futian Zhao, Zheng Liu, Chen Ou, Ruihong Zhuang
Summary: The sliding friction behavior of granular geomaterials is a challenging problem in the discrete element method (DEM) analysis. In this study, experiments were designed to determine the sliding friction coefficient between particles of different shapes and contact forms, as well as between particles and different boundaries. The experimental results were fitted and embedded into DEM software, and the simulated results showed high consistency with the experimental results. The proposed experiment method can determine the sliding friction coefficient in DEM simulation and improve the accuracy of the simulation results.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Physical
Hokun Kim, Duc Tam Ho, Sung Youb Kim
Summary: This study shows that the fracture behavior of cracked metal nanoplates is size-dependent. Smaller cracked nanoplates exhibit elastic instability-dominant fracture followed by ductile behavior, while larger cracked nanoplates exhibit brittle fracture. The transition in fracture behavior is due to the competition between the crack and the free surfaces.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Engineering, Mechanical
Xuejie Zhang, Wei Sun, Wei Wang, Kun Liu
Summary: Granular friction behaviors were investigated during a linear reciprocating sliding process using a customized experimental apparatus. The evolution of two normal forces on the shearing unit qualitatively reflected the effects of the force chain network. The coefficient of friction reached a stable value rapidly within the initial sliding stage and remained constant, showing a significant decrease with external load and a slight increase with sliding velocity.
Article
Engineering, Multidisciplinary
Jozef Kresak, Pavel Peterka, Lubomir Ambrisko, Martin Mantic
Summary: The paper presents measurements of the friction coefficient of mine hoisting machine friction linings, comparing different rubber samples with a standard friction lining. Hardness was chosen as a discriminator due to the confidentiality of material composition. The study aimed to maintain the stability of the friction coefficient under various external conditions.
EKSPLOATACJA I NIEZAWODNOSC-MAINTENANCE AND RELIABILITY
(2021)
Article
Materials Science, Multidisciplinary
Jeffrey L. Streator
Summary: In this study, a combination of a local, elastic deformation model and dynamic simulation was used to investigate nanoscale slip between a rigid, curved pin and an elastic slab and its impact on static and kinetic friction. The findings demonstrate a direct connection between the nanoscale slip characteristics and the macroscopically observed coefficients of friction.
FRONTIERS IN MATERIALS
(2022)
Article
Engineering, Mechanical
Yiming Zhao, Gang Yi, Jiuyu Cui, Ziqian Zhao, Yonggan Yan, Luxing Wei, Jinlong Shao, Hongbo Zeng, Jun Huang
Summary: Understanding the friction behavior of hydrogels is crucial for their bioengineering applications. This study revealed an unexpected low friction regime when a polyacrylamide hydrogel was rotated against a glass substrate under alternative sliding velocity cycles. The findings provide new insights into the lubrication behaviors and mechanisms of hydrogels, with implications for engineering applications such as artificial cartilage.
Article
Engineering, Multidisciplinary
Djordje Vukelic, Petar Todorovic, Katica Simunovic, Jasmina Miljojkovic, Goran Simunovic, Igor Budak, Branko Tadic
Summary: This paper presents a novel method for determining kinetic friction coefficient based on the time it takes a rigid body to travel a distance along an inclined plane. Experimental results show that the mean kinetic friction coefficient increases with increasing mean sliding velocity, while increasing sliding velocity increases deviation of friction coefficients. This method also allows the determination of energy consumed due to friction along the traveled distance.
TEHNICKI VJESNIK-TECHNICAL GAZETTE
(2021)
Article
Chemistry, Physical
Mang Gao, Soo-Bin Kim, Yahui Li, Shreeharsha H. Ramaswamy, Junho Choi
Summary: This study used Si-incorporated diamond-like carbon (Si-DLC) films as non-polymer dielectric materials for sliding-mode triboelectric nanogenerators (TENGs) to enhance output and durability. The Si-DLC film with higher Si content exhibited higher triboelectric output under dry conditions and further enhanced output and durability under unsubmerged water-lubricated conditions. This research proposed an integrated strategy for designing durable self-driving sensing systems in machinery.
Article
Chemistry, Multidisciplinary
Ahmad A. Khalaf, Muammel M. Hanon
Summary: This study analyzed the friction coefficient and wear rate of ductile cast iron with different microstructures, using an artificial neural network model for prediction. The results showed a decrease in friction coefficient with increasing sliding speed, and a lower wear rate with higher sliding speeds. The bainite structure was found to be harder and wear-resistant compared to the ferrite structure.
APPLIED SCIENCES-BASEL
(2022)
Article
Materials Science, Multidisciplinary
Alena Uhnakova, Anna Machova, Jan Cerv, Petr Hora, Jaroslav Joch
Summary: Through molecular dynamics simulations, it was found that cleavage fracture is supported by surface emission of oblique dislocations and their subsequent cross slip, which increases separation of the cleavage planes inside the crystal. Under slower loading rates, crack growth is hindered by the generation of twins on oblique planes, resulting in a ductile fracture.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
Alexandre Megret, Loic Prince, Marie-Georges Olivier, Veronique Vitry
Summary: The use of lightweight materials is required in automotive and aerospace fields. Magnesium and its alloys possess low density, high mechanical properties, and excellent thermal conductivity. However, they suffer from low corrosion and wear resistances. The combined action of corrosion and wear is critical for these materials.
Review
Geosciences, Multidisciplinary
Michael J. Heap, Marie E. S. Violay
Summary: The microstructure and mineralogy of volcanic rocks are diverse and complex, affecting their mechanical behavior. Parameters such as porosity, void space partitioning, pore and crystal size, and alteration, as well as external factors like water, strain rate, and temperature, all play a role in determining the uniaxial compressive strength of volcanic rocks. Through experimental data and analysis, differences between brittle and ductile mechanical behavior in volcanic rocks are highlighted, with discussions on factors like stress-strain curves, porosity evolution, and acoustic emission activity during deformation experiments. The study also touches upon the fracture toughness, mechanical properties, and failure modes of volcanic rocks, emphasizing the importance of understanding these aspects for monitoring volcanic hazards effectively.
BULLETIN OF VOLCANOLOGY
(2021)
Article
Agronomy
Shengwei Zhang, Jun Fu, Ruiyu Zhang, Yan Zhang, Hongfang Yuan
Summary: This study investigated the mechanical properties of tiger nut tubers and found that factors such as friction, collision, and compression were influenced by various parameters. The results of this study are important for the design and optimization of machinery for the harvesting and processing of tiger nut tubers.
Article
Materials Science, Multidisciplinary
Alejandra Moreno-Barcenas, Jesus Alejandro Arizpe Zapata, Miguel Angel Esneider Alcala, Jaime Tellez Ramirez, Antonio Magana Hernandez, Alejandra Garcia-Garcia
Summary: The wear of materials is a critical problem in the industry. Graphene, as a tribological coating, has been found to have a significant impact on sliding surfaces. This study focuses on growing a few layers of graphene on a nodular cast iron substrate commonly used in camshafts. The synthesis parameters and quality of the coating were investigated, and the results showed that the best results were obtained at 10 sccm and 4 degrees C/min in terms of the structure and deposition of graphene. The few layers of graphene coating demonstrated a 60% reduction in coefficient of friction and a close to 70% reduction in volume removed compared to uncoated substrates.
Article
Engineering, Mechanical
Yangshou Xiong, Quanwei Wang, Kang Huang, Zongshan Zhou
Summary: In a transmission system, the combination of metal small gears and plastic large gears can reduce weight and noise, as well as ensure strength and longevity. However, research on metal-plastic friction is still insufficient. This study focused on the ADC12-POM gear pair and conducted friction tests to determine the friction coefficients under different conditions. A calculation model for the friction coefficients was established.
TRIBOLOGY TRANSACTIONS
(2023)
Article
Geochemistry & Geophysics
R. Ruggieri, M. M. Scuderi, F. Trippetta, E. Tinti, M. Brignoli, S. Mantica, S. Petroselli, L. Osculati, G. Volonte, C. Collettini
Summary: The presence of weak phyllosilicates in mature carbonate fault zones can significantly affect frictional strength, stability, and healing, especially under wet conditions. An increase in shale content leads to a reduction in frictional strength and a transition from velocity-weakening to velocity-strengthening behavior.
Article
Geochemistry & Geophysics
Matthew S. Tarling, Steven A. F. Smith, Jeremy S. Rooney, Cecilia Viti, Keith C. Gordon
Summary: The study identifies a new type of mineralogically banded serpentine crack-seal vein, where thin bands of chrysotile are followed by thicker bands of polygonal serpentine/lizardite. This suggests a common set of processes involving crack opening and sealing in various structural sites within serpentinite-bearing faults and shear zones.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geochemistry & Geophysics
Piercarlo Giacomel, Roberta Ruggieri, Marco M. Scuderi, Elena Spagnuolo, Giulio Di Toro, Cristiano Collettini
Summary: The study investigates the frictional properties of unaltered basalts under various conditions, highlighting the significant impact of microstructural heterogeneities on friction velocity dependence. Results suggest that friction instabilities may promptly nucleate in shear zones within basaltic gouge layers, whereas joint surfaces characterized by rough rock-on-rock contacts are less prone to unstable slip.
Article
Geochemistry & Geophysics
G. Volpe, G. Pozzi, E. Carminati, M. R. Barchi, M. M. Scuderi, E. Tinti, L. Aldega, C. Marone, C. Collettini
Summary: Crustal seismicity usually occurs within the seismogenic layer, which is typically below 10 km depth, and its lower boundary is influenced by the properties of the sedimentary cover and rock. Studies in the central-northern Apennines have shown that seismic sequences primarily occur within the sedimentary cover, indicating the significant role of the basement in dictating the depth of the seismogenic zone.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Multidisciplinary Sciences
Matthew S. Tarling, Steven A. F. Smith, Marianne Negrini, Li-Wei Kuo, Wei-Hsin Wu, Alan F. Cooper
Summary: Based on microstructural analysis of nephrite jade samples from Taiwan, California, and New Zealand, a conceptual model for the evolution of nephrite jade is proposed. Four types of nephrite jade are distinguished based on formation mode and textural characteristics. The study suggests that different types of nephrite jade can evolve through processes such as dissolution-precipitation, crenulated and foliated metamorphic fabrics, and transient brittle deformation.
SCIENTIFIC REPORTS
(2022)
Article
Geochemistry & Geophysics
Giacomo Pozzi, Marco M. Scuderi, Elisa Tinti, Manuela Nazzari, Cristiano Collettini
Summary: Fault stability is closely related to the frictional and healing properties of fault rocks and associated fabrics. The reactivation and slip behavior of dolomite-anhydrite analog faults are controlled by fault fabrics. The study reveals that changes in normal stress can result in different fault behaviors, such as large stress drops and high slip velocities, or low stress drops and slow stick-slip events. The integration of microstructural and mechanical data suggests that frictional and chemically assisted healing processes play a relevant role in developing large instabilities in natural faults. Additionally, fault rock heterogeneity modulates the slip velocity function and the dynamics of repeating stick-slip cycles.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geosciences, Multidisciplinary
C. J. Tulley, A. Fagereng, K. Ujiie, S. Piazolo, M. S. Tarling, Y. Mori
Summary: This study reveals the deformation mechanisms and rheological behavior of antigorite, suggesting that dissolution-precipitation creep and dislocation activity contribute to the foliation development of antigorite.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
C. Collettini, M. R. Barchi, N. De Paola, F. Trippetta, E. Tinti
Summary: Analysis of the 2016-2017 Central Italy seismic sequence reveals that seismic activity not only occurs along major fault structures, but also within volumes of Triassic Evaporites with a different frequency-magnitude distribution. The study suggests that ductile crustal deformation can cause distributed microseismicity.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Corentin Noel, Carolina Giorgetti, Marco M. Scuderi, Cristiano Collettini, Chris Marone
Summary: Fault stability is influenced by fault zone width, structural complexity, fault rock wear rate, and the presence of gouge during frictional sliding. Shear displacement plays a key role in the transition from stable to unstable sliding, and strain localization is an important factor controlling fault stability. The rate-and-state parameters (a-b) and D-c are affected by shear displacement and wear rate, with enhanced velocity weakening and potential instability observed for larger fault slip.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Marshall C. Palmer, James M. Scott, Steven A. F. Smith, Petrus J. le Roux, Chris Harris, Marianne Negrini, Matthew S. Tarling
Summary: By analyzing the Sr isotope data from metasomatic rocks in the Dun Mountain Ophiolite, we have determined the timing of mantle and crust juxtaposition, providing evidence for the closure of a fore-arc ocean basin during the middle Jurassic.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Mineralogy
Matthew S. Tarling, Matteo Demurtas, Steven A. F. Smith, Jeremy S. Rooney, Marianne Negrini, Cecilia Viti, Jasmine R. Petriglieri, Keith C. Gordon
Summary: The study found that the serpentine mineral lizardite has strong Raman anisotropy in the OH-stretching region, and the wavenumber shifts depend on the orientation of the excitation laser relative to the crystallographic axes. By studying well-characterised lizardite samples, the relationship between crystallographic orientation and Raman wavenumber was quantified, providing a simple and cost-effective technique for measuring and quantifying lizardite-bearing serpentinite fault rocks. This technique is particularly useful when EBSD alone is insufficient.
EUROPEAN JOURNAL OF MINERALOGY
(2022)
Article
Geochemistry & Geophysics
Matteo Demurtas, Steven A. F. Smith, Elena Spagnuolo, Giulio Di Toro
Summary: The study focused on the frictional and microstructural evolution of calcite and dolomite gouges under different slip rates and conditions, showing that the presence of water strongly influenced the behavior. The research found that at room humidity, slip strengthening occurred up to certain slip rates, while in water-dampened conditions, gouge fluidization was observed. The results suggest caution when relating fluidization textures to seismic slip in natural fault zones.