Article
Engineering, Mechanical
Mikel Iribecampos, Ibai Ulacia, Aitor Arana, Jon Larranaga
Summary: Traction in lubricated rolling and sliding contacts is crucial for the performance of machine elements. The combined effects of contact scale and spin motion on traction have not been studied before. This study developed a novel semi-analytical model considering spin motion and found that increasing contact size and spinning speed reduces traction coefficient and contact efficiency due to thermal effects. These findings have important practical implications for designing machine elements.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Yuko Higashitani, Sanemasa Kawabata, Marcus Bjorling, Andreas Almqvist
Summary: This article investigates the traction characteristics of rolling/sliding EHL contacts in the linear isothermal region and proposes a prediction formula for the dimensionless traction coefficient. The formula, obtained through numerical simulations, is applicable for piezoviscous rigid/elastic and isoviscous rigid/elastic regimes.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Gan-Yun Huang, Yi-Ran Li
Summary: Friction is a common phenomenon in daily life and production, which can be either detrimental or beneficial. This study investigated the friction behavior at microscale using the JKR model and analogy with dislocation emission at crack tips, and proposed a mechanical model for rolling adhesion.
EXTREME MECHANICS LETTERS
(2021)
Article
Engineering, Mechanical
Chao Li, Hongmei Liu, Hao Gao, Yuanfa Zhao, Teng Xiang, Qingtao Li
Summary: This paper studies the kinematic qualities and contact models of a novel zero-spin rolling conical CVT and designs the rollers and conical disks based on proposed design principles. The transmission efficiency of the novel CVT is investigated and compared with a half toroidal CVT. The results show that the novel CVT has smaller practical spin ratio and spin momentum, leading to higher efficiency on fixed transmission ratio compared to the half toroidal CVT.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING
(2023)
Article
Agronomy
Kaihua Liu, Marco Benetti, Marco Sozzi, Franco Gasparini, Luigi Sartori
Summary: This study examines tractor performance under different traction resistance conditions and finds that soil stress, soil physical properties, and slip rate increase with increased traction and number of passes. The permanent traffic lane has lower slip rate and energy consumption compared to uncompacted and compacted soil.
Article
Engineering, Mechanical
Francesc Perez-Rafols, Lucia Nicola
Summary: A model is proposed to study the incipient sliding of contacts in the presence of friction and adhesion, showcasing different contact pressure profiles under varying parameters. Experimental investigation is conducted on the contact between a smooth cylinder and a flat body under strong adhesion-friction interactions.
Article
Biotechnology & Applied Microbiology
Zhensheng Zhong, Can Zhang, Rui Liu, Jun He, Han Yang, Zijie Cheng, Tao Wang, Meng Shao, Shu Fang, Shengzhao Zhang, Hui Shi, Rufeng Xue, Huijuan Zou, Zeyu Ke, Zhiguo Zhang, Jinhua Zhou
Summary: This study presents an optical-tweezers-based method to evaluate the chirality and frequency of sperm rotation. By analyzing the intensity distribution patterns of off-focus micron-size particles, the orientation of the sperm head along the optical axis can be determined, and both rolling chirality and rolling frequency of the sperm can be measured. The study found that vertically trapped human sperm cells exhibit right-hand longitudinal rolling. The developed rotation analysis method may have clinical potential for sperm quality evaluation.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
Article
Engineering, Mechanical
Juan Guillermo Zapata Tamayo, Marcus Bjorling, Yijun Shi, Braham Prakash, Roland Larsson
Summary: The study demonstrated that lubricating steel-steel contacts with Glycerol-water-glycol lubricant reduced mild wear and promoted micro-pitting as the main failure mode at low sliding levels compared to a commercial fully formulated gear oil. It was also observed that friction was significantly lower for the Glycerol-water and Glycerol-water-glycol lubricants, mainly due to a low pressure-viscosity coefficient.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Xiaomeng Zheng, Jian Liu, Sanming Du, Yongzhen Zhang
Summary: This study aimed to investigate the formation and alteration of tribofilm during pure rolling contact under sufficient lubrication. Rolling contact experiments with varying stress cycles were conducted using a ball-rod testing machine. Characterizations on surface state including morphology, roughness and plastic deformation were executed and chemical composition and valence state of tribofilm were detected for different rolling periods. The results indicated that tribofilm was formed and evolved due to the effect of Hertz Contact stress, causing surface morphology changes and plastic deformation. Micro-sliding destroyed the tribofilm to a certain degree, resulting in the change of surface state and tribofilm composition compared to the pure rolling region.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Jeremy J. Wagner, Sriram Sundararajan
Summary: This study investigates the transitions in failure modes in low lambda applications. It finds that there is a transition from pitting/abrasive wear to micropitting and then to mild abrasive wear/no failure. The composition and coverage of the tribofilm differ under different conditions, with similar thickness. The presence of ZDDP elements in the tribofilm promotes micropitting, and increased tribofilm coverage leads to longer life. Additionally, higher levels of retained austenite and compressive residual stress contribute to longer life.
Article
Engineering, Mechanical
Tshenolo Phinah Leso, Charles Witness Siyasiya, Roelf Johannes Mostert, Joseph Moema
Summary: The demand for railway services has increased, leading to higher speeds and axle loads. As a result, wheel and rail wear severity has increased. This study aimed to investigate the wear and rolling contact fatigue performance of class B wheels on R350HT and R260 rails under different slip ratios. The findings showed that wear severity was heavily influenced by the slip ratio. Additionally, the wear rate of class B wheels was found to be lower on R260 rail compared to R350HT rail. Three wear regimes, namely mild, severe, and catastrophic, were identified based on wear rate and wear index (T gamma/A).
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Xiangyun Deng, Yi-Qing Ni, Xiubo Liu
Summary: This study uses a validated finite element method to evaluate the wheel-rail slip behaviors and focus on the contact during wheel traction. The factors affecting wheel slips, such as friction and traction coefficients, are investigated. The study reveals that wheel slips can occur even when the traction coefficient is slightly smaller than the limiting value. The study provides insights into the wheel slip mechanism and theoretical guidance for the development of more accurate control methods.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Physics, Applied
Grant A. Riley, Justin M. Shaw, Thomas J. Silva, Hans T. Nembach
Summary: The accurate measurement of exchange interaction in ferromagnetic ultra thin films is challenging. Various methods have been used, but consensus has not been reached. This study presents a method using Brillouin light scattering to measure spin wave dispersion and determine exchange, saturation magnetization, and magnetic thickness simultaneously.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Mechanical
Michael Dawoud, Stephan Beitler, Hubert Schwarze
Summary: The slip behavior of different cage types in an NU215 cylindrical roller bearing was studied. It was found that all tested bearings started to operate without slip at higher forces than recommended by the manufacturer. Increasing oil flowrate or rotational speed increased slip under insufficient radial forces. The single-part outer-ring-guided brass cage had lower slip than its two-part equivalent, while roller guidance had the least slip tendency. The polyamide cage offered lighter weight but higher slip, whereas the full complement bearings offered higher load-carrying capacity with higher slip.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2023)
Article
Engineering, Multidisciplinary
Liu YuQing, Chen ZaiGang, Wang KaiYun, Zhai WanMing
Summary: Wear is a major cause of bearing failure, and this study analyzes the causes and evolution of motor bearings surface wear in locomotives. The results demonstrate the impact of wear on the vibration and safety of the traction motor and neighboring components.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2022)
Article
Engineering, Mechanical
Busra Duran, Jerome Cavoret, David Philippon, Fabrice Ville, Arnaud Ruellan, Frank Berens
Summary: This study analyzes the changes in the physicochemical properties and tribological performances of gear transmission oils during field operation, finding differences from traditional engine oils.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Baocheng Liu, Hongsheng Chen, Jun Zhou, Jing Wang, Wenxian Wang, Xiaochun Chen, Sanxiao Xi
Summary: This study used fast hot pressing sintering to fabricate WC/AlCoCrFeNi2.1 metal matrix composites (MMCs). It was found that the addition of reinforced particles increased the microhardness, nanoindentation and wear resistance of the MMCs. During frictional processes, an oxide film formed, providing material protection, enhancing stability and reducing friction-induced losses.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Pradip Kumar Verma, Alok Singh
Summary: This study investigates the mechanical properties and wear resistance of CoMoMnNiV high entropy alloy reinforced aluminium matrix composite processed through stir-squeeze casting assisted with an ultrasonic transducer. The results show significant improvements in mechanical properties and wear resistance, with the composite containing 8 wt% HEA demonstrating the highest resistance to wear. Optical microscopy, SEM, and an optical profilometer were used for a thorough examination of the microstructure and worn surface.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Zhenghai Yang, Yingjian Song, Jinlong Jiao, Wenbo Li, Bao Shangguan, Yongzhen Zhang
Summary: This study investigated the friction, wear properties, and current-carrying properties of copper-graphite composites paired with brass C28000. The results showed that the current-carrying properties of the composite materials were excellent, but their wear rate was the main limiting factor. Furthermore, an increase in the thickness of the graphite layer led to an improvement in the uniformity of damage.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Moustafa Mahmoud Yousry Zaghloul, Karen Steel, Martin Veidt, Michael T. Heitzmann
Summary: This research evaluates and compares the impact of different material types on the tribological characteristics of Polyamide 6 composites, and finds that glass fiber-reinforced Polyamide 6 exhibits better friction and wear performance under high-pressure velocity factors.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Shaoqing Qin, Lida Zhu
Summary: In this paper, the surface and subsurface damage of laser assisted grinding CrCoNi medium entropy alloys were investigated using molecular dynamics simulations. The results showed that the application of laser energy can reduce cutting forces and minimize subsurface damage.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Kaikui Zheng, Youxi Lin, Tingzheng Lai, Chenghui Gao, Ming Liu, Zhiying Ren
Summary: The study investigated the use of waste foundry resin-bonded sand as a substitute for copper in resin-based brake material. It found that the waste sand was more favorable for improving the overall friction and wear properties of the material compared to copper. Waste sand benefited the material by forming a friction layer, leading to increased friction coefficient and stability. Brake material with 10-15% waste sand showed excellent heat-fade resistance.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Dayang Li, Fanhao Zhou, Yutong Gao, Kun Yang, Huimin Gao
Summary: This article introduces a continuous prediction model based on deep learning for predicting the power output of steam turbines. The model uses long short term memory (LSTM) method to develop a trend prediction model and optimizes the prediction model through feature selection method. Experimental results show that the model outperforms other models in terms of prediction performance.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Tomohiro Toyoda, Ryo Yasuike, Toshihiro Noda
Summary: In this study, a elasto-plastic constitutive model of friction incorporating the concept of superloading surface was developed based on the subloading friction model. The proposed model achieves a smooth transition of friction by describing the evolution rule of structure, treating the state with static friction coefficient larger than kinetic friction coefficient as the bulkiness of structure. The positive definiteness of the plastic multiplier, loading condition, and material parameters were derived, and the validity of the proposed model in accordance with the subloading-friction model was confirmed through a stick-slip simulation of a mass-spring system.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
P. Balaji, B. Surya Rajan, K. Sathickbasha, P. Baskara Sethupathi, Deviga Magadevan
Summary: This study emphasizes the importance of using a variety of solid lubricants with different oxidation temperature regimes to enhance the tribological performance of brake pads.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Jian Ma, Yancong Liu, Javad Mostaghimi, Na Zhang
Summary: This paper investigates the influence of preparation strategies on the lubrication properties of surface textures. Three laser scanning strategies are proposed to achieve a sinusoidal textured surface, and the evolution of surface structure and chemical composition is discussed. The findings show that ridge structures enhance anti-wear properties but also increase the friction coefficient. However, the oil cover preparation method prevents the formation of ridges and improves wettability.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Mohammad Roostaei, Arvin Taghizadeh Tabrizi, Hossein Aghajani
Summary: In this research, the Al2O3/MoS2 nanocomposite coating layer was successfully applied on the surface of Ti-6Al-4 V alloy. The relation between the surface characteristics and wear resistance of the coating was studied using atomic force microscopy analysis and pin-on-disk wear test method. The results showed that the nanocomposite coating significantly reduced the wear rate and provided an equation to calculate the Lancaster coefficient.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Musa Bilgin, Sener Karabulut, Halil Karakoc, Yunus Kayir, Murat Sarikaya
Summary: This study investigates various methods to improve the machinability efficiency of Inconel 718 alloy while considering their effect on microstructural properties. The results show that hot+PMQL, hot+SiCNMQL, and hot+Al2O3-NMQL contribute significantly to the improvement of machinability characteristics. The EBSD analysis also reveals that a limited area is affected by heat in the hot machining environment and that the removal of the heated layer during milling process helps preserve the microstructure.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Q. Gao, Y. Fan, Y. G. Wu, J. L. Liu, J. Wang, L. Li
Summary: Fretting wear significantly affects the hysteresis behavior of the contact surface and leads to joint degradation. This study investigates the influence of harmonic normal force on the evolution of interface morphology and contact parameters with fretting wear. The results show that the harmonic normal force can significantly influence the hysteresis loop and the energy dissipation distribution on the contact surface.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Benjamin Weiland, Floriane Leclinche, Anis Kaci, Brigitte Camillieri, Betty Lemaire-Semail, Marie -Ange Bueno
Summary: This study presents a systematic approach to generating control signals for a tactile simulator that simulate the touch of textile fabrics. By using a friction modulation tactile surface and acquiring forces from real surfaces with artificial finger mimicking fingerprints, control signals are generated and processed in the frequency domain before sending them to the tactile stimulator. The study focuses on the potential benefits of incorporating fingerprint information in fabric simulations to achieve a more realistic tactile perception. A sensory analysis with 36 participants using the generated control signals showed better discrimination without fingerprint information.
TRIBOLOGY INTERNATIONAL
(2024)