Article
Engineering, Mechanical
M. El Laithy, L. Wang, T. Harvey, A. Schwedt, Wolfram Kruhoeffer, Joachim Mayer
Summary: This investigation analyzed 520 butterfly formations and non-metallic inclusions in two roller bearings to study their influence on butterfly formation. The results showed that duplex inclusions had the highest formation rate, larger inclusions and those with smaller aspect ratios were more prone to formation, and the orientation of butterfly formations was influenced by inclusion size and stress level.
TRIBOLOGY INTERNATIONAL
(2023)
Review
Engineering, Mechanical
Yansheng Ma, Jiangfeng Hu, Xuecheng Dong
Summary: This article discusses the importance of rolling bearings in various mechanical systems and the potential problems they may face, as well as the role of surface engineering technologies in improving rolling bearings. It reviews the performance of physical vapor deposition coatings on rolling/sliding contacts and rolling bearings, and summarizes the applications and factors influencing coating performance in the rolling bearing industry.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2022)
Article
Engineering, Mechanical
X. Z. Liang, P. E. J. Rivera-Diaz-del-Castillo
Summary: This study investigates the influence of hydrogen on microstructural alterations in components subjected to rolling contact fatigue (RCF). A dislocation-assisted carbon migration model is developed to describe the formation of hydrogen-influenced microstructural alterations. The experimental results confirm the effectiveness of the model.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
T. Schirra, G. Martin, S. Puchtler, E. Kirchner
Summary: This paper presents an experimental setup and calculation procedure for measuring and predicting the electric impedance of rolling bearings as a sensor model for bearing loads. By considering unloaded rolling elements and the undeflected area of loaded rolling elements, the model has been improved to provide more accurate predictions compared to the state of the art. However, there is still a difference between measurement and calculation, which requires further approaches to reduce the discrepancy.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Oliver Menck
Summary: This paper discusses the challenges in calculating the fatigue life of bearings under certain conditions and the limitations of existing standards. It proposes a numerical approach based on ISO 281 to calculate the life of bearings under stochastic operating conditions, with examples including the life calculation of a rotor blade bearing in a wind turbine.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2023)
Article
Chemistry, Physical
Philipp Hoellmer, A. C. Maggs, Werner Krauth
Summary: Event-chain Monte Carlo algorithms for hard-disk dipoles in two dimensions are benchmarked for potential applications in modeling water molecules. The rotation dynamics of dipoles are characterized through integrated autocorrelation times of polarization. The non-reversible event-driven ECMC algorithms show significant speedups compared to the Metropolis algorithm, with differences in speed observed among ECMC variants, indicating Newtonian ECMC as a promising solution for overcoming dynamical arrest in dipolar models with Coulomb interactions.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Engineering, Mechanical
Guillermo E. Morales-Espejel, Armando Felix Quinonez
Summary: The paper presents a stress-based model for predicting the life of rolling/sliding contacts in machine elements, considering surface and subsurface survival. The model requires input of the contact stress distribution and lubrication quality. It is illustrated using the example of spur gears and shows the ability to predict gear endurance and the contribution of the surface. This approach is advantageous for future gear design and applicable to rolling bearings and cam-follower systems.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Chemistry, Analytical
Einar Lovli Hidle, Rune Harald Hestmo, Ove Sagen Adsen, Hans Lange, Alexei Vinogradov
Summary: This paper proposes a knowledge-based data analysis algorithm for health condition monitoring in rotating machinery, specifically targeting the early detection of subsurface cracks induced by contact fatigue. A robust fault detector is introduced and its efficacy is demonstrated through a long-term durability test on a case-hardened steel roller. The reliability of subsurface crack detection is confirmed by independent periodic ultrasonic inspections. Subsurface cracks as small as 0.5mm are identified and their steady growth is tracked using the proposed acoustic emission (AE) technique. Challenges and future prospects of this methodology are discussed.
Article
Physics, Applied
Jan Kaiser, Supriyo Datta
Summary: The article discusses a probabilistic computer based on p-bits that can accelerate randomized algorithms used in various applications, such as Bayesian networks, optimization, Ising models, and quantum Monte Carlo. A generic architecture for p-computers and simulations with thousands of p-bits are proposed to demonstrate their potential for significant speedup.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Mechanical
Yuhao Zhao, Yanyang Zi, Zhenyi Chen, Mingquan Zhang, Yuanhang Zhu, Jianshu Yin
Summary: Ball bearings in liquid rocket turbopumps operating under extreme conditions generate significant power loss. To understand the power loss mechanism, a theoretical model considering cryogenic fluid and solid lubricant influence is proposed, which simulates the rolling-sliding behavior of balls. Eight power loss components of the bearing are deduced based on tribology and kinematic analysis. The proposed model is validated and shows that sliding, spinning, and hydraulic power losses are the most important components. Additionally, the tribological behavior of the ball affects the distribution of power loss components.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Mechanical
Xiaochen Zhang, Di Wu, Zhuofan Xia, Yifeng Li, Jianqiu Wang, En-Hou Han
Summary: This research investigates the surface damage mechanism of hybrid ceramic ball bearings. The study shows that due to the higher hardness of ceramic balls compared to traditional bearing steel, the surface fatigue behavior differs, resulting in the formation of micropits and degradation of precision bearing performance.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Materials Science, Multidisciplinary
Jee-Hyun Kang, Jungwoong Kim, Jun-Yun Kang, Soon-Woo Kwon, Min-Woo Kang, Seung Hyun Hong
Summary: This study provides an in-depth characterization of the formation mechanism of the dark-etching region (DER) caused by rolling contact fatigue in bearing steel. The results reveal that the accumulation of plastic flow and dynamic recrystallization contribute to the hardness reduction and etching behavior, which may lead to spalling of the bearing.
Article
Automation & Control Systems
Taoufik Najeh, Jan Lundberg
Summary: This study aims to develop a vibration-based bearing monitoring approach using the ARX-Laguerre model and genetic algorithms to estimate the remaining useful life of bearings. The proposed model shows effectiveness in tracking the evolution of bearing health state and accurately estimating the bearing's RUL.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Engineering, Mechanical
Lucas Fourel, Jean-Philippe Noyel, Etienne Bossy, Xavier Kleber, Philippe Sainsot, Fabrice Ville
Summary: A numerical model for rolling contact fatigue using finite element method and micromechanical model is developed, showing that mesoscopic consideration offers benefits over macroscopic approach in handling dented surfaces, while orthogonal shear stress computation on macroscopic model is legitimate for Hertzian contact. Mesoscopic modeling allows for life scatter on fatigue crack threshold, with initiation depths consistent with literature experiments.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Lucas Fourel, Jean-Philippe Noyel, Etienne Bossy, Xavier Kleber, Philippe Sainsot, Fabrice Ville
Summary: A mesoscopic model for simulating the initiation of rolling contact fatigue (RCF) cracks is proposed in this study, using Finite Element Method (FEM) with cubic elasticity and polycrystalline geometry. Results show consistent initiation depths.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Gyan Ranjan, Rajiv Tiwari
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2020)
Article
Engineering, Mechanical
Nilakshi Sarmah, Rajiv Tiwari
MECHANISM AND MACHINE THEORY
(2020)
Article
Engineering, Mechanical
Prabhat Kumar, Rajiv Tiwari
Summary: A novel model-based identification algorithm is developed in this paper to estimate the unbalance and AMB misalignment in a rigid rotor system levitated with active magnetic bearings (AMBs). The algorithm uses mathematical modeling and numerical simulations to analyze the displacement and stiffness characteristics between the rotor and AMBs.
IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY-TRANSACTIONS OF MECHANICAL ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Meduri Kalyan, Rajiv Tiwari, Md Saif Ahmad
SADHANA-ACADEMY PROCEEDINGS IN ENGINEERING SCIENCES
(2020)
Article
Automation & Control Systems
Siva R. Srinivas, Rajiv Tiwari, Ch Kanna Babu
Summary: This paper presents a new approach for identifying misalignment in coupled rotor systems, utilizing ACS matrix coefficients as direct indicators of misalignment type and severity. The developed identification algorithm is based on least-squares linear regression technique and testing the sensitivity to signal noise and bias errors in modeling parameters.
JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME
(2021)
Article
Engineering, Multidisciplinary
Rajiv Tiwari, D. J. Bordoloi, Aakash Dewangan
Summary: Centrifugal pumps are crucial in industrial applications, but operational faults may occur during operation. Monitoring the health status of the pumps is essential. This study focuses on using fluid pressure to identify blockages and cavitation in centrifugal pumps, and assess their severity.
Article
Engineering, Mechanical
Prabhat Kumar, Rajiv Tiwari
Summary: This paper investigates the finite element modelling, analysis, and identification of a fully-levitated flexible rotor with faults using active magnetic bearings. A novel trial misalignment approach is proposed for simultaneous estimation of rotor residual unbalance and AMB residual misalignment, and force-displacement and force-current stiffness coefficients of AMBs are identified. The study demonstrates the reliability and robustness of the proposed algorithm through numerical testing against measurement noise and rotor modeling errors.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Engineering, Multidisciplinary
Gyan Ranjan, Rajiv Tiwari, H. B. Nemade
Summary: On-site estimation of multiple fault parameters was conducted in a rotor with active-magnetic bearing (AMB) and a cracked shaft supported on flexible conventional bearings. The study considered internal damping effects from a transverse crack and proposed a Multiple Harmonic Influence Coefficient Method (MHICM) to obtain fault parameters of the rotor.
INVERSE PROBLEMS IN SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Dhiraj Kumar, Aakash Dewangan, Rajiv Tiwari, D. J. Bordoloi
Summary: This paper focuses on the accurate identification of blockage faults in the inlet pipe of centrifugal pump through the use of deep learning algorithms and a combination of different types of sensors. The methodology involves multiclass classification for blockage detection, emphasizing the importance of multi-source data collection. The use of different sensor combinations can achieve close to 100% accuracy in identifying blockage levels.
Article
Engineering, Multidisciplinary
Gyan Ranjan, Rajiv Tiwari, H. B. Nemade
Summary: A practical online balancing methodology for rotor systems supported on conventional bearings using an Active Magnetic Bearing (AMB) is proposed. The methodology eliminates the need for mechanical trial masses and estimates residual unbalances using an Improved Influence Coefficient Method (IICM).
SADHANA-ACADEMY PROCEEDINGS IN ENGINEERING SCIENCES
(2022)
Article
Computer Science, Artificial Intelligence
Ahmad Abbasi, Behnam Firouzi, Polat Sendur, Gyan Ranjan, Rajiv Tiwari
Summary: A novel optimization-based method is proposed to determine the parameters of a rotating unbalance in a rotor-bearing system. The efficiency of the method is compared with various optimization algorithms, validating its superiority.
Article
Acoustics
Gargi Majumder, Rajiv Tiwari
Summary: This study investigates the use of Active Magnetic Bearings (AMBs) in controlling gear vibrations in gearbox to reduce component failures and transmitted noise. Through the development of a mathematical model and experimental validation, it is found that AMBs can effectively reduce vibration levels and overall noise levels of geared rotor.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Mechanical
Gargi Majumder, Rajiv Tiwari
Summary: This study focuses on the mathematical modelling, analysis, active transverse vibration control and fault analysis of a single-stage spur geared-rotor system. It utilizes Active Magnetic Bearings (AMBs) and closed-loop feedback control system to minimize vibration and noise caused by gear deformation and transmission error, protecting the integrity of gears and supporting structures.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Review
Engineering, Mechanical
Prabhat Kumar, Rajiv Tiwari
Summary: In this review article, the research findings on investigating the vibrational nature of rotating machineries under multiplicative faults and their identification in various dynamic models are summarized. Multiplicative faults occur when the process is influenced by the products of process variables. The causes for occurrence of multiplicative faults and different model-based techniques for identifying them are described. The article also includes studies on compound faults, fault diagnosis using artificial intelligence techniques, and fault diagnosis in rotary machines for underwater vehicles.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2023)
Article
Automation & Control Systems
Atul Kumar Gautam, Rajiv Tiwari
Summary: This study focuses on the modeling and response analysis of two coupled rotor systems subjected to shaft bow and coupling angular misalignment, integrated with an active magnetic bearing (AMB). The study found that angular misalignment introduces additional coupling stiffness and changes the intact stiffness. The presence of bow generates a multiplicative load, affecting multi-harmonic responses. The adoption of AMB helps to control vibrations caused by multiplicative faults.
INTERNATIONAL JOURNAL OF DYNAMICS AND CONTROL
(2023)