Article
Engineering, Mechanical
Zeliang Xiao, Xi Shi, Xi Wang, Xiaolong Ma, Yunting Han
Summary: The lubrication performance of herringbone gear is degraded by increased pressure and temperature rise due to larger tooth surface roughness and rotational speed. In the start-stop phase, the tooth wear depth of herringbone gear may be greatly reduced with a larger start-stop acceleration. Overall, the research indicates that large tooth surface roughness is more likely to cause thermo-mechanical and wear failures in herringbone gear drive compared to high load.
Article
Chemistry, Physical
Qian Zhao, Zuoxiang Xing, Jing Yuan, Zhijun Zhang, Jun Zhu, Huiming Jiang
Summary: This study proposes an improved wear modeling and analysis method for double-arc harmonic gears that is more in line with actual conditions. The study establishes a tooth surface wear model under mixed elastohydrodynamic lubrication (EHL) and conducts numerical simulation analysis to study the wear characteristics. The results show that wear depth for mixed EHL is significantly less than at dry contact, and the double-arc tooth profile can withstand more wear cycles than the involute tooth profile. The study provides a theoretical basis for the structural optimization design, wear reduction, and life prolonging of harmonic gears.
Article
Engineering, Mechanical
Jiang Zhao, Wei Sheng, Zhengminqing Li, Hong Zhang, Rupeng Zhu
Summary: The contact and lubrication characteristics of the gear pair are directly affected by the relative sliding at the meshing point. This study investigates a new type of low sliding ratio gear pair and establishes a 3D elastohydrodynamic lubrication line contact model. The results show that the LSR gears have increased film thickness, reduced friction coefficient compared to involute gears.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
Yi Shen, Tao He, Xiaoya Gong
Summary: This paper presents a lubrication model that comprehensively considers the influence of contact geometry, lubrication properties and three-dimensional real surface roughness to analyze the lubrication performance of harmonic gears under different conditions.
INDUSTRIAL LUBRICATION AND TRIBOLOGY
(2023)
Article
Engineering, Mechanical
Xiang Yuan, Jun Wang, Zisheng Lian, Guofa Wang
Summary: An experimental and theoretical research on seal behavior was conducted in this work, using an innovative mixed lubrication model incorporating EHD theory. The computational procedure provided insight into the effects of seal pressure, rod velocity and compression ratio on sealing characteristics, accurately predicting friction force and providing a theoretical basis for EHL modeling.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Zhaoming Yin, Zhimin Fan, Feng Jiang
Summary: This paper investigates the calculation method of oil film stiffness for double involute gears and its influencing factors. The results show that the type of gears and operating conditions have a certain influence on the oil film stiffness.
CHINESE JOURNAL OF MECHANICAL ENGINEERING
(2021)
Article
Engineering, Mechanical
Daofei Wang, Jialong Yang, Pengchong Wei, Wei Pu
Summary: This article focuses on the application of grease lubrication in rolling element bearings and the establishment of a mixed EHL model. Experimental results show that the grease friction behavior corresponds well with the variation of grease film thickness.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Metallurgy & Metallurgical Engineering
Wen-kang Huang, Hui Ma, Zhi-fang Zhao, Peng-fei Wang, Zhi-ke Peng, Xiao-xu Zhang, Song-tao Zhao
Summary: Elastohydrodynamic lubrication (EHL) plays a crucial role in improving the stability and reliability of gear transmissions by reducing surface deformation and friction. A proposed model investigates the complex relationship between EHL and time-varying mesh stiffness (TVMS) in spur gears and aims to solve the TVMS under EHL. The model incorporates EHL, slice coupling, extended tooth contact (ETC), gear body coupling flexibility, and modified tooth stiffness. The effects of EHL and slice coupling on meshing characteristics are analyzed, showing that considering slice coupling significantly increases the TVMS of gears with crowning and shifts the load distribution towards the middle of the tooth side.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2023)
Article
Engineering, Mechanical
Congcong Fang, Yongdong Peng, Wei Zhou, Guangjun Gao, Xianghui Meng
Summary: This paper presents a numerical analysis method for the mixed EHL of finite-line contacts considering tilting loads based on FEM. The Reynolds and linear elasticity equations, and Greenwood-Tripp contact model are coupled in an iterative process to solve the fluid-solid/solid-solid interaction under the compound external force and moment. The lubrication characteristics at both ends of the cylinder are analyzed, and an asymmetric profile design scheme is proposed to improve the lubrication performance at the cylinder's lower end. It is found that proper profile parameters can significantly reduce EHL pressure, increase the minimum oil film thickness, and decrease asperity contact pressure.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
H. P. Evans, R. W. Snidle
Summary: Duncan Dowson's groundbreaking contribution to elastohydrodynamic lubrication theory has had a significant impact on the understanding of lubrication in gear tooth contacts and provided a reliable reference formula in gear design standards. This paper demonstrates the application of elastohydrodynamic lubrication theory in engineering component design and highlights the importance of considering surface roughness effects in micro-elastohydrodynamic lubrication for addressing current issues like micropitting.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Engineering, Mechanical
Jiaxing Pei, Xu Han, Yourui Tao, Shizhe Feng
Summary: A method for analyzing the lubrication reliability of spur gear systems considering the randomness of external load and surface roughness is presented. The study captures the instantaneous failure probability of gear lubrication through a stochastic dynamics model and a reliability model of elastohydrodynamic lubrication (EHL), revealing higher lubrication failure probability in dedendum and single meshing region.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Xinming Li, Feng Guo, Gerhard Poll, Yang Fei, Ping Yang
Summary: This study investigates the evolution of grease films in rolling elastohydrodynamic lubrication (EHL) contacts with glass disc revolutions. The patterns of grease film evolution were found to be highly related to speed ranges and grease structures, shedding light on mechanisms such as transfer of thickener lumps, decay in film thickness due to starvation, and the formation of an equilibrium film. The primary mechanisms governing grease film formation in different lubricated contacts were clarified through the research.
Article
Engineering, Mechanical
Xingbao Huang, Bintang Yang, Youqiang Wang
Summary: This paper presents a mathematical model of gear elastohydrodynamic lubrication, considering transient impact operating condition and underdamped load condition. The numerical solution shows that transient impact results in significant increases in film pressure and temperature, while thermal effect causes decreases in film thickness. Additionally, vibrational load with high damped frequency leads to greater changes in film thickness and friction coefficient compared to low damped frequency, with a corresponding increase in film temperature.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Multidisciplinary Sciences
Yanzhong Wang, Kai Yang, Xiaomeng Chu, Wen Tang, Changyong Huang
Summary: An engineering calculation model is introduced to analyze point-contact elastohydrodynamic lubrication of spiral bevel gears, revealing the transient lubrication characteristics and film thickness variations during the meshing process.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Mechanical
Quentin Allen, Bart Raeymaekers
Summary: We investigate the convergence of elastohydrodynamic lubrication (EHL) simulations for textured slider bearings, which are computationally expensive due to the coupling of equations and additional simulation requirements. We quantitatively analyze the convergence of EHL simulations for textured slider bearings with various parameters and conclude that a careful consideration of discretization, convergence metric, and criterion is crucial for achieving accurate numerical simulations. Our study also highlights the potential of a well-designed convergence analysis in reducing computational costs.
Article
Engineering, Mechanical
R. Gholami, Saleh Akbarzadeh, S. Ziaei-Rad, M. M. Khonsari
Summary: The study aims to investigate the impact of nano-particles' weight fraction on the friction coefficient in mixed-lubrication regime through experimental and theoretical analysis. Results demonstrate good agreement between theoretical and experimental findings, with a parametric study conducted to explore additional influencing factors.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Engineering, Mechanical
Behnam Hajshirmohammadi, Michael M. Khonsari
Summary: An online approach using thermoelectricity was proposed to predict the fatigue life of metallic specimens under cyclic loading. The methodology was validated with experimental results, showing a practical methodology for early prediction of fatigue. The correlation between thermoelastic potential and fatigue life was demonstrated in low-carbon steel 1018 specimens measured via an infrared camera.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Arash P. Jirandehi, M. M. Khonsari
Summary: A statistical method is presented for estimating the plastic strain energy per cycle in metals under fatigue. The distribution of plastic strain under cyclic loading follows a two-parameter Weibull probability function and a second probability function is incorporated to account for different crystallographic directions. Results from a thermodynamically based model and a finite element model support the predictions made using the statistical method.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
A. Nourian-Avval, M. M. Khonsari
Summary: This paper proposes a model for predicting fatigue life under multiaxial loading based on dissipated heat during fatigue tests, evaluating fatigue damage by considering different rates of dissipated energy under various multiaxial loadings. The predictive capability of the models is confirmed through comparison with experimental fatigue results.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
M. Mehdizadeh, M. M. Khonsari
Summary: The study presented an experimental and theoretical analysis of low carbon steel 1018 subjected to multiaxial loading, showing that different loading conditions affect fatigue life. The use of thermography for fatigue life prediction was more accurate than hysteresis loops in capturing specimens' fatigue life under multiaxial fatigue loading.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Joonyoung Jang, Michael M. Khonsari
Summary: A new nonlinear fatigue damage accumulation model is developed in this paper, which considers the loading sequence effect and predicts the rate of damage by introducing a loading sequence parameter. The applicability of the proposed model is validated using nine sets of independent experimental measurements of fatigue life under multiple loading sequences, showing that the predictions are in agreement with the measured results and providing a reliable estimation of fatigue life.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Review
Engineering, Mechanical
Arash P. Jirandehi, Michael M. Khonsari
Summary: Recent progress in microstructure-sensitive research has led to insights on estimating fatigue damage and predicting useful life. A computational crystal plasticity approach incorporating statistical representations of material microstructure and a new thermodynamically based framework has been suggested.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Materials Science, Composites
Ali Mahmoudi, Michael M. Khonsari
Summary: A new approach utilizing the concepts of kinetic strength and fracture fatigue entropy can reliably predict the fatigue life of laminated composites by considering the temperature and time dependence through Zhurkov's model.
JOURNAL OF COMPOSITE MATERIALS
(2022)
Article
Engineering, Mechanical
Ali Mahmoudi, M. M. Khonsari
Summary: A new method based on the fracture fatigue entropy (FFE) criterion is proposed to predict the fatigue life of metals. This method utilizes the concept of kinetic strength of solid materials to rapidly predict the cyclic plastic strain energy and temperature evolution. Experimental results for Al 7075-T6, LCS 1018, API 5L X52, and MCS 1045 are compared with theoretical predictions, demonstrating that this model can reliably predict the temperature evolution, plastic strain energy dissipation, and fatigue life of metals.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Arash P. Jirandehi, Ali Haghshenas, M. M. Khonsari
Summary: In this study, fully-reversed bending fatigue and impulse excitation tests were conducted to investigate the behavior of High Carbon Steel (HCS) at different environmental temperatures. It was found that with increasing environmental temperature, the specimens tended to become more brittle, leading to a decrease in fatigue life.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Chemical
Soroosh Salehi, Sahar Ghatrehsamani, Saleh Akbarzadeh, M. M. Khonsari
Summary: This paper presents an experimental procedure and a thermodynamic methodology for evaluating adhesive wear in systems with variable and sequential speeds. The continuum damage mechanics (CDM) is used to estimate the probability of asperities forming wear particles and derive the wear coefficient. The results show that the wear coefficient in descending cases is higher than in ascending velocity experiments. Additionally, Archard's law is not suitable for predicting wear volume in situations with variable speeds.
Article
Physics, Multidisciplinary
Mohammad A. Amooie, K. P. Lijesh, Ali Mahmoudi, Elaheh Azizian-Farsani, Michael M. Khonsari
Summary: The effect of sudden variations in working modes and fatigue behavior of CS 1018 is studied using a general model based on the concept of fracture fatigue entropy (FFE). Fully reversed bending tests are conducted on dog bone specimens with variable frequency tests to simulate fluctuating working conditions. The results show that regardless of frequency changes, FFE remains constant and within a narrow band range, similar to a constant frequency.
Article
Engineering, Mechanical
Mohammad A. Amooie, M. M. Khonsari
Summary: This study investigates the fracture behavior of carbon steel 1018 in low-temperature environments. Fully-reversed bending experimental tests were performed to examine the efficacy of using Fracture Fatigue Entropy (FFE) concept for predicting fatigue life at different environmental temperatures. The results show that lower operating temperatures can improve fatigue life of carbon steel. Additionally, FFE remains nearly constant and can be used for reliable prediction of fatigue life at different environmental temperatures. Illustrative examples are provided to demonstrate the utility of this approach for prediction purposes.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Mechanics
A. Mahmoudi, M. R. Khosravani, M. M. Khonsari, Tamara Reinicke
Summary: This study investigates the accumulated entropy at the crack tip of a semi-circular bending (SCB) specimen to determine the threshold for material fracture and interatomic debonding. The plastic flow at the crack tip is measured using the Digital Image Correlation (DIC) technique and strain maps superposed to SCB specimens. The generated entropy at the crack tip reaches a critical limit, beyond which bond breakage occurs, leading to crack surface propagation.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Ali Mahmoudi, Mohammad A. Amooie, Lijesh Koottaparambil, Michael M. Khonsari
Summary: This study introduces a reliable technique for predicting the remaining useful life of components by measuring the temperature signature when the operating frequency is rapidly changed. The approach is validated through fatigue tests on stainless steel specimens. The method allows for predicting the remaining useful life at different operating frequencies.
Article
Engineering, Mechanical
Yankui Song, Ke Xiao, Guo Xiang
Summary: The novelty of this study lies in constructing an Entropy-based wear and fluid-solid-thermal (FST) coupled model for journal bearings, and revealing the transient interaction behavior between wear evolution and FST evolution during repeated starting and stopping. The wear rate is measured experimentally, and the contact temperature, friction coefficient and normal contact force are obtained from the validated FST model. Wear tests and numerical calculations are conducted to validate the predicted wear rate and investigate the time-varying wear and FST evolution of journal bearings.
Article
Engineering, Mechanical
Xin-long Liu, Xin Guan, Yuan Zhong, Qian Xiao, Yong Cao, Wu-lue Zhang, Song Zhang, Yi-ting Zheng, Ming-sheng Gao, Dao-yun Chen, Wen-bin Yang
Summary: Gaps in the conductor rail joints of intercity trains have an impact on current transmission and the wear of carbon skateboards. These gaps decrease the coefficient of friction, increase electrical contact resistance, and affect the wear rate of carbon skateboards.
Article
Engineering, Mechanical
Yuhang Wu, Conglin Dong, Xiuqin Bai, Chengqing Yuan
Summary: The study developed a new composite material by incorporating hexagonal boron nitride (h-BN) particles into a thermoplastic polyurethane (TPU) matrix, which exhibited excellent self-lubricating properties and reduced frictional excitation forces. The addition of h-BN particles effectively reduced the coefficient of friction, decreased fluctuation amplitude, enhanced wear resistance, and attenuated vibration behaviors.
Article
Engineering, Mechanical
Tiancheng Ouyang, Xiuyang Sun, Wentao Tang, Yinxuan Li, Zhi Qun Tian, Yanzhou Li
Summary: By adding nitrogen-doped graphene and C60 nanoparticles to the lubricant, a highly efficient nano-lubricant with vibration and noise reduction properties is synthesized.
Article
Engineering, Mechanical
Xin Zhuo, Jun Cao, Haibo Huang, Li Liu, Xinkun Suo, Peiqing Ye, Zeshan Abbas
Summary: A polymer coating prepared by liquid spraying technology on the surface of 20CrMo steel demonstrates good tribological and anti-cavitation erosive properties. It can effectively replace CuPb24Sn copper alloy in valve plates for pumps under different lubrication conditions. The coating exhibits adhesive wear and reduces frictional loss, and mainly shows abrasive wear under complex working conditions. Its lipophilicity, high hardness to elastic modulus ratio, and corrosion resistance are the main influencing factors for its performance.
Article
Engineering, Mechanical
Md. Aminul Islam, Jiaren (Jimmy) Jiang, Yongsong Xie
Summary: Erosion-corrosion is a major factor in material loss and reduced useful life of hydro-transport equipment. This study evaluates the erosion-corrosion characteristics of different materials and finds that matrix wear affects the degradation of carbides. Sufficient wear and corrosion resistance in the surrounding matrix are important for good erosion-corrosion resistance.
Article
Engineering, Mechanical
Andre Dubois, Oussama Filali, Laurent Dubar
Summary: This study investigates the effect of surface roughness, contact pressure, and lubrication on the onset of galling in aluminum 6082-T6 using a pin-on-plate tribometer. The experimental results show that the roughness and lubricants play a significant role in preventing galling.
Article
Engineering, Mechanical
Jizhan Wu, Peitang Wei, Guoqiang Liu, Difa Chen, Xiuhua Zhang, Taimin Chen, Huaiju Liu
Summary: This study conducted a comprehensive evaluation of the DLC coating treatment on the loading capacity of gears and characterized the surface features and fatigue performance. The results demonstrate that DLC coating significantly improves the hardness and surface residual compressive stress of the gears, as well as enhances their contact fatigue performance.
Article
Engineering, Mechanical
Yangping Liu, Hwaran Lee, Annsley Mace, Jeremy L. Gilbert
Summary: An AFM-based single asperity tribology method was used to investigate the wear performance of carbides and base metal matrix in high carbon CoCrMo alloy. The wear behavior of the two types of carbides was stress-dependent and influenced by chemical composition. Cr-rich carbides exhibited higher wear resistance compared to Mo-rich carbides.
Article
Engineering, Mechanical
Zdenek Riha, Michal Zelenak, Akash Nag, Jakub Poloprudsky, Tomas Kruml, Sergej Hloch
Summary: This study investigates the erosion performances of a high-speed modulated jet (MWJ) and continuous water jet (CWJ). By comparing different nozzles and water jet powers, the effects of modulated and continuous jets on aluminum alloy were studied. The results show that under certain conditions, modulated jet can create deeper and sharper grooves while reducing the impact of lateral flow.
Article
Engineering, Mechanical
Chunyu Yu, Weipu Li, Yang Guo, Xianbin Sun, Fanli Hong, Ning Sun, Qinghai Zhang
Summary: This study explores the relationship between the wear rate of train brake pads and its features, and proposes a method for predicting the wear rate suitable for small sample data. Grey relational analysis and Pearson correlation analysis are used to determine the preferred features that affect the wear rate, and a BOA-BP model is established for prediction. The results show that BOA-BP exhibits better advantages in prediction with small samples.
Article
Engineering, Mechanical
Shan Yin, Xin Zhao, Shuangchao Huang, Zefeng Wen, Xuesong Jin
Summary: This study simulated the rolling contact of a driving wheelset over tangent and curved tracks at a speed up to 500 km/h using an explicit finite element approach to derive creep curves. The comparison between quasi-steady curves and transient curves in the presence of rail corrugation helped to identify cases where traditional theories are inapplicable and where transient effects must be considered. Additionally, the study further analyzed the influence of middle/high-frequency vibrations in the presence of rail corrugation.
Article
Engineering, Mechanical
Jiyao Zhang, Yuanlie Yu, Junlei Tang, Yingying Wang, Honggang Sun, Kaikai Song, Jianhong Gong, Pingping Liu, Xiaoming Liu, Lina Hu, Parthiban Ramasamy, Juergen Eckert
Summary: The influence of high-carbon addition on the microstructure, hardness, and wear behavior of CoCrNi alloy was investigated. It was found that the addition of carbon resulted in the formation of carbide particles, enhancing the hardness and improving the wear resistance. Fracture and detachment of hard carbides during friction introduced additional abrasive particles, transitioning the wear mechanism from adhesive-dominated to abrasive-dominated.
Article
Engineering, Mechanical
Yanfei Liu, Shengtao Yu, Ruize Zhang, Xiangyu Ge, Wenzhong Wang
Summary: This study reports the tribological behavior of nanodiamond plate (NDPL) as a nanoadditive for the first time and compares it with nanodiamond particles (NDPA). The results show that NDPL provides better lubrication performance at higher concentrations, and the sliding between NDPLs and the structural transformation from sp3 to sp2 carbon play a crucial role in lubrication and wear resistance.
