Article
Chemistry, Analytical
Guoda Chen, Yijie Chen
Summary: The aerostatic spindle in the ultra-precision machine tool exhibits complex multi-field coupling dynamics behavior, which can be better understood and improved through numerical investigation. A proposed 5-DOF dynamics model considers the interaction between the air film, spindle shaft, and motor, showing good performance in simulating the multi-field coupling behavior under external forces. This research contributes to further study of the dynamic characteristics of the aerostatic spindle.
Article
Engineering, Mechanical
Jianbo Zhang, Zhifang Deng, Kun Zhang, Hailiang Jin, Tao Yuan, Ce Chen, Zhimin Su, Yitao Cao, Zhongliang Xie, Danyang Wu, Jingping Sui
Summary: In this paper, the steady state and dynamic performances of aerostatic bearings are studied using the finite difference method. The linear stability of the aerostatic bearing is also investigated. The results show that geometry parameters, rotational speed, and supply pressure have significant effects on the performances of aerostatic bearings.
Article
Engineering, Mechanical
Jianbo Zhang, Dongjiang Han, Zhongliang Xie, Chao Huang, Zhushi Rao, Mingbo Song, Zhimin Su
Summary: In this paper, a dynamic model of the aerostatic bearing-rotor system is established to investigate the influences of rotational speed, unbalance, rotor mass, and supply pressure on the nonlinear behaviors of the system. The results demonstrate various nonlinear phenomena, including periodic and quasi-periodic motions. Additionally, it is found that proper adjustments of the unbalance, rotor mass, and supply pressure can control the nonlinear vibration and enhance system stability.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Mathematics
Yangong Wu, Jiadai Xue, Zheng Qiao, Wentao Chen, Bo Wang
Summary: The characteristics of the squeeze film in aerostatic bearings were investigated using the dynamic Reynolds equation. The results showed that for compressible lubricants, the squeeze effect exhibited damping at zero frequency and stiffness at infinite frequency. The dynamic pressure in the static high-pressure region was also high at high frequencies due to gas compressibility. Transfer functions of the thin film were derived to analyze the dynamic performance of aerostatic bearings.
Article
Engineering, Mechanical
Lei An, Wei Wang, Chaoqun Wang
Summary: A bidirectional fluid-structure coupling dynamic model is established to analyze the dynamic properties of high-speed aerostatic journal bearing with recess, by coupling the governing equation of the transient air film flow, the flow balance equation, and the rotor motion equation. The influences of operating parameters on the coupling system are theoretically and experimentally analyzed based on trajectory of rotor axis, trajectory of rotor center, Poincare map, time response of rotor, frequency spectrum, mass flow rate, and bifurcation diagram. The results indicate abundant nonlinear behavior and determine the instability parameters of the system. This study provides guidance for the theoretical design and practical operation of this type of system.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Computer Science, Information Systems
Tengfei Yin, Guoqing Zhang, Jianjun Du, Suet To
Summary: This paper presents a nonlinear analysis of the stability and dynamic rotational accuracy of an unbalanced rotor supported by aerostatic journal bearings. Using a finite element method and Runge-Kutta fourth order method, the dynamic response of the rotor under varying rotor masses is analyzed. It is found that the dynamic responses strongly depend on the rotor mass, with different motion patterns observed as the mass changes.
Article
Mechanics
Guangding Wang, Huiqun Yuan
Summary: This paper investigates the dynamics and stability of an axially functionally graded hollow rotor partially filled with liquid. Analytical expressions for whirl frequency equation and stability prediction model are obtained for an exponentially graded liquid-filled rotor with simply supports. The results show the significant influence of parameters on whirl speed and system stability.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Mechanical
Niranjan Singh, Rajeev Kumar Awasthi
Summary: The study found that different shapes of textures have different effects on the performance of journal-bearing systems, with spherical textures providing the best improvement in performance. The most pronounced effect of texture shapes on performance is when the aspect ratio of surface textures is 1.0.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Engineering, Mechanical
Mikael Miettinen, Valtteri Vainio, Rene Theska, Raine Viitala
Summary: The study experimentally investigated the performance and feasibility of a novel design for a robust air bearing with aerostatically sealed pressurized volume, and characterized its suitable operating domain based on load capacity, friction moment, chamber flow, and seal flow rate measurements under various conditions. The results provided corroborative evidence on the feasibility of the proposed chamber-based bearing design.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Rajdeep Deb, Andreas Hunkeler, Dirk Wilhelm, Patrick Jenny, Beat H. Meier
Summary: Numerical stability analysis was performed on aerostatic bearings for small cylindrical rotors. The modified Reynolds equation was used to obtain optimized design parameters and the maximum stable inertial force. Experimental observations and numerical investigations confirmed the role of nozzle diameter, nozzle number, and gas molecular weight in enhancing rotor spinning frequency.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Computer Science, Interdisciplinary Applications
Yangong Wu, Zheng Qiao, Jiadai Xue, Bo Wang, Wentao Chen
Summary: This study focuses on evaluating the performance of orifice-type aerostatic bearings using the finite element method. Inappropriate boundary settings are found to cause significant numerical errors. Through numerical modeling and analysis, the study proposes the use of auxiliary sources and rules for boundary condition settings, which are validated through experiments.
ADVANCES IN ENGINEERING SOFTWARE
(2022)
Article
Acoustics
Zilin Li, Jiakang Yao, Long Ma, Guojun Yang, Mindong Lyu, Yuming Wang, Zixi Wang
Summary: A horizontal rotor is typically studied in the research of rotor drop failure in active magnetic bearing (AMB) test rigs, while vertical rotor drop failure is not well understood. Experiments show that the vertical rotor dynamic response after dropping on the touchdown bearing (TDB) is complex and includes dry whirl and dry whip processes. To predict the dynamic response of a vertical rotor drop failure, this study develops a theoretical model based on a rotor-TDB system and validates it with an AMB-TDB rotor experiment. The results indicate that the natural whirl speed and critical speed distinguish between dry whirl and dry whip motion, and factors such as TDB parameters and rotor unbalance significantly affect the natural whirl speed.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Engineering, Mechanical
Yi Zhang, Wei Wang, Daogao Wei, Gang Wang, Jimin Xu, Kun Liu
Summary: The study investigates the potential unstable vibration phenomena of the floating-ring bearing supported turbocharger rotor system in high-speed and high-temperature environments. A numerical model is used to analyze its nonlinear vibration behavior and a method to avoid fluid-induced instability is proposed.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Multidisciplinary
C. Liu, S. Y. Pei, B. T. Li, H. L. Liu, J. Hong
Summary: This paper solves the Reynolds equation of the lubrication problem in hybrid bearing using high-order isogeometric analysis method and demonstrates its application in complex structures. The results show that the high-order isogeometric analysis method accurately applies boundary conditions and improves computational efficiency.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Mathematics
Vladimir Kodnyanko, Stanislav Shatokhin, Andrey Kurzakov, Lilia Strok, Yuri Pikalov, Iakov Pikalov, Olga Grigorieva, Maxim Brungardt
Summary: The disadvantage of aerostatic bearings lies in their low dynamic quality, but an improved design with features such as simple diaphragms and elastic suspension can enhance the dynamic characteristics of the bearings.
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)