Article
Engineering, Mechanical
Lei Deng, Shuaishuai Sun, Qihao Wu, Ning Gong, Jiang Yang, Shiwu Zhang, Haiping Du, Weihua Li
Summary: This study develops a highly stable quasi-zero stiffness (QZS) vibration isolation system integrated with magnetorheological fluids (MRFs) to overcome the unstable problem of QZS systems and expand their application range.
NONLINEAR DYNAMICS
(2023)
Article
Engineering, Mechanical
Laurence F. Wagner, Paul E. Allaire
Summary: This study discusses the influence of vibrational frequencies on the dynamic properties of tilting-pad journal bearings, proposing a single-pad, two degree-of-freedom model. Analyzing the frequency dependency of stiffness and damping coefficients, it emphasizes the importance of pivot flexibility in achieving alignment between theory and experiment.
Article
Computer Science, Information Systems
D. K. Supreeth, Siddappa Bekinal, Shivamurthy Rokkad Chandranna
Summary: This article reviews the research on electrodynamic passive magnetic bearings (EDB) and provides an in-depth examination of EDB modeling, analysis, and development. The article highlights different types of EDB configurations, improvements in technology, advancements in mathematical modeling, finite element techniques, and experiments used to determine bearing characteristics with high accuracy. The article also reviews critical developments in rotordynamic analysis for high-speed application and discusses advances in the application of EDB.
Article
Polymer Science
Umer Sharif, Xinmei Xiang, Miaochang Zhu, Jun Deng, Jing Sun, Dauda Sh. Ibrahim, Orelaja Oluseyi Adewale
Summary: The current study focuses on the production and experimental examination of sandwich beams consisting of an aluminum face sheet and 3D-printed honeycomb cores filled with magnetorheological elastomer (MRE). The results suggest that the proposed sandwich beam constructions have the ability to alter the damping ratio, damping coefficient, and stiffness through the application of a magnetic field. Significant variations in damping were observed when the magnets were located in the central regions of the structures.
Article
Instruments & Instrumentation
Ashok Kumar Kariganaur, Hemantha Kumar, M. Arun
Summary: This study evaluates the temperature effect of MR fluid on system performance, analyzing the behavior and characterization of the fluid at different temperatures. The results provide insights for improving MR system design and performance prediction, by understanding the stability and property changes of the fluid under various temperature conditions.
SMART MATERIALS AND STRUCTURES
(2022)
Article
Automation & Control Systems
Xuanchun Yin, Jinchun Yan, Sheng Wen, Jiantao Zhang
Summary: This article presents a design of magnetorheological (MR) fluid-filled origami joints with variable stiffness characteristics, which can be controlled remotely using magnets. A theoretical model is derived and calibrated to predict the joint stiffness under different magnetic flux densities. The MR fluid-filled origami joints are demonstrated to enhance stiffness in complex origami structures, and jamming behavior is introduced to achieve variable stiffness using a weak magnetic setup. Additionally, the origami robot filled with MR fluid is capable of carrying loads while crawling on flat ground and climbing on an inclined surface.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Engineering, Mechanical
Yu Huang, Haiyin Cao, Zhuxin Tian
Summary: This study found two threshold speeds for long journal bearing, and pointed out that stability boundary behaves differently when the rotating speed is different from short bearing.
Article
Engineering, Mechanical
Hongyang Hu, Ming Feng, Tianming Ren
Summary: A new type of gas foil conical bearing was proposed to reduce the mass and size of low-power turbine machinery, with its static and dynamic performance systematically studied. The results show that the new bearing has excellent supporting performance and broad prospects for application, with parameters such as bump radius, rounding radius, friction coefficients, and foil thickness significantly influencing the bump foil stiffness.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Yongsok Seo
Summary: A magnetorheological (MR) slurry is developed as a completely different concept from the MR suspension, and it exhibits unprecedented ultra-high yield stress and permanent stability. This breakthrough is expected to expand the application of MR fluids to diverse industries. Additionally, a simple fitting equation for the yield stress as a function of the particle volume fraction is proposed.
Article
Engineering, Mechanical
Dezhao Lin, Fan Yang, Di Gong, Ruihong Li
Summary: This study proposes a new vibration isolator based on Magnetorheological Elastomer (MRE) with tunable stiffness-damping and active driving properties. Experimental tests demonstrate the significant tunable range of stiffness and damping, as well as the adjustable transmission properties of the isolator. It is also shown that the MRE component can drive a mass of considerable weight under specific excitation frequencies. Therefore, the proposed MRE vibration isolator holds great potential in the field of vibration control with fail-safe properties.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Mechanics
Airton Nabarrete, Gustavo de Freitas Fonseca
Summary: The paper investigates the application of mechanical couplings in rotating machinery, studying the effects of rotor misalignment on vibration stability through theoretical and experimental analysis. The finite element model and nonlinear response evaluation are utilized to assess the performance of the rotor system under rigid coupling misalignment.
Article
Chemistry, Multidisciplinary
Hyung-Yoon Choi, Jin-Yeong Choi, Hyun-Ho Park, Tae-Hyeon Kim, Hyoung Jin Choi, Chang-Seop Lee
Summary: This study introduced magnetic MnFe2O4 nanoparticles and graphene oxide to enhance the magnetorheological properties and dispersion stability of carbonyl iron-based MR fluid. The prepared CI/MnFe2O4/GO was transformed into CI/MnFe2O4/rGO through an annealing process and used as an additive for the MR fluid. The CI/MnFe2O4/rGO-based MR fluid exhibited improved shear stress, shear viscosity, and storage modulus compared to the CI-based MR fluid, with enhanced dispersion stability attributed to the properties of GO.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2021)
Article
Nanoscience & Nanotechnology
Tianxiang Du, Penghui Zhao, Yu Tong, Ning Ma, Hao Huang, Xufeng Dong
Summary: Fe-Co nanoparticles were successfully synthesized by DC arc discharge and low temperature annealing in Ar atmosphere, with a saturation magnetization of 208 emu g(-1), coercivity of 58 Oe, and remanent magnetization of 5.8 emu g(-1). FeCoNP-MRFs exhibited a dynamic shear stress of 4.61 kPa at a magnetic field of 436 kA m(-1), excellent reversibility, and a sedimentation ratio of 87.3% after 72 hours, indicating good sedimentation stability.
Article
Energy & Fuels
Gudeta Berhanu Benti, David Rondon, Rolf Gustavsson, Jan-Olov Aidanpaa
Summary: This paper investigates and compares the dynamics of tilting pad journal bearings (TPJB) with four and eight pads through experimental and numerical analysis. The results show that the four-pad TPJB excites specific frequencies in the system, unlike the eight-pad TPJB, and the amplitudes of these frequencies increase with the rotor speed.
JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
Philipp Zemella, Daniel Vetter, Thomas Hagemann, Hubert Schwarze
Summary: This study experimentally investigates the influence of pad preload and pivot offset on the frequency-dependent characteristics of dynamic stiffness and damping coefficients of tilting-pad journal bearings. The results validate the effectiveness of dynamic bearing modeling.
Article
Computer Science, Interdisciplinary Applications
D. A. Bompos, P. G. Nikolakopoulos
SIMULATION MODELLING PRACTICE AND THEORY
(2016)
Article
Engineering, Mechanical
Leonidas I. Paouris, Dimitrios A. Bompos, Pantelis G. Nikolakopoulos
JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME
(2014)
Article
Computer Science, Interdisciplinary Applications
Dimitrios A. Bompos, Pantelis G. Nikolakopoulos
SIMULATION MODELLING PRACTICE AND THEORY
(2011)
Article
Engineering, Industrial
Dimitrios Bompos, Julien Chaves-Jacob, Jean-Michel Sprauel
CIRP ANNALS-MANUFACTURING TECHNOLOGY
(2020)
Proceedings Paper
Engineering, Marine
Dimitrios A. Bompos, Pantelis G. Nikolakopoulos
PROCEEDINGS OF THE ASME TURBO EXPO: TURBINE TECHNICAL CONFERENCE AND EXPOSITION, 2014, VOL 1B
(2014)
Proceedings Paper
Engineering, Mechanical
D. A. Bompos, P. G. Nikolakopoulos, C. I. Papadopoulos, L. Kaiktsis
PROCEEDINGS OF THE ASME TURBO EXPO 2012, VOL 5
(2012)