The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
F Chevalier - One of the best experts on this subject based on the ideXlab platform.
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rolling Bearing Stress based life part i calculation model
Journal of Tribology-transactions of The Asme, 2012Co-Authors: L Houpert, F ChevalierAbstract:Rolling contact Bearing life is calculated using Stresses calculated at the surface and in the volume. Surface Stresses account for profile and misalignment as well as asperity deformations. Sub-surface Stresses are calculated beneath the asperities (for defining the life of the surface) and deeper in the volume for calculating the life of the volume. The Stress-life criterion adopted is the Dang Van one in which the local stabilized shear Stress is compared to the material endurance limit defined as a function of the hydrostatic pressure (itself a function of the contact pressure) but also residual Stresses and hoop Stresses (due to fit). A Stress-life exponent c, of the order of 4 (instead of 34/3 in the standard Lundberg and Palmgren model) is used for respecting a local load-life exponent of 10/3 at typical load levels. Life of any circumferential slices of the inner, outer, and roller is defined for obtaining the final Bearing life. Trends showing how the Bearing life varies as a function of the applied Bearing load and Λ ratio (film thickness/RMS roughness height) are given.
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Rolling Bearing Stress Based Life—Part I: Calculation Model
Journal of Tribology-transactions of The Asme, 2012Co-Authors: L Houpert, F ChevalierAbstract:Rolling contact Bearing life is calculated using Stresses calculated at the surface and in the volume. Surface Stresses account for profile and misalignment as well as asperity deformations. Sub-surface Stresses are calculated beneath the asperities (for defining the life of the surface) and deeper in the volume for calculating the life of the volume. The Stress-life criterion adopted is the Dang Van one in which the local stabilized shear Stress is compared to the material endurance limit defined as a function of the hydrostatic pressure (itself a function of the contact pressure) but also residual Stresses and hoop Stresses (due to fit). A Stress-life exponent c, of the order of 4 (instead of 34/3 in the standard Lundberg and Palmgren model) is used for respecting a local load-life exponent of 10/3 at typical load levels. Life of any circumferential slices of the inner, outer, and roller is defined for obtaining the final Bearing life. Trends showing how the Bearing life varies as a function of the applied Bearing load and Λ ratio (film thickness/RMS roughness height) are given.
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Rolling Bearing Stress Based Life—Part II: Experimental Calibration and Validation
Journal of Tribology-transactions of The Asme, 2012Co-Authors: J. Gnagy, L Houpert, F ChevalierAbstract:The Stress based life model described in Paper I was calibrated using a large database of experimental results from a global quality audit test program as well as special development tests conducted for this validation effort. All tests used in the calibration of the new model were case carburized or through hardened tapered roller Bearings. The initial model comparison to test results showed very good correlation with a median ratio of test life to calculated life very close to one. Higher accuracy of the Stress based model compared to the traditional factor based method was also demonstrated by narrower confidence bands (less data scatter). Validation testing of case carburized tapered roller Bearings as well as through hardened spherical roller Bearings was also conducted under expanded test conditions beyond those utilized in the quality audit test program (i.e., high and low load, high and low λ, imposed misalignment, and heavy inner ring interference fits). Although the median ratio of relative life for the validation testing showed the Stress based method to be conservative and well above one, the Stress based method still showed better accuracy than the traditional factor based method as well as narrower confidence bands for this additional body of experimental data. The conservative results can be explained by use of high quality steel and manufacturing processes in a prototype facility and not series production equipment as was the case with the quality audit database.
L Houpert - One of the best experts on this subject based on the ideXlab platform.
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rolling Bearing Stress based life part i calculation model
Journal of Tribology-transactions of The Asme, 2012Co-Authors: L Houpert, F ChevalierAbstract:Rolling contact Bearing life is calculated using Stresses calculated at the surface and in the volume. Surface Stresses account for profile and misalignment as well as asperity deformations. Sub-surface Stresses are calculated beneath the asperities (for defining the life of the surface) and deeper in the volume for calculating the life of the volume. The Stress-life criterion adopted is the Dang Van one in which the local stabilized shear Stress is compared to the material endurance limit defined as a function of the hydrostatic pressure (itself a function of the contact pressure) but also residual Stresses and hoop Stresses (due to fit). A Stress-life exponent c, of the order of 4 (instead of 34/3 in the standard Lundberg and Palmgren model) is used for respecting a local load-life exponent of 10/3 at typical load levels. Life of any circumferential slices of the inner, outer, and roller is defined for obtaining the final Bearing life. Trends showing how the Bearing life varies as a function of the applied Bearing load and Λ ratio (film thickness/RMS roughness height) are given.
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Rolling Bearing Stress Based Life—Part I: Calculation Model
Journal of Tribology-transactions of The Asme, 2012Co-Authors: L Houpert, F ChevalierAbstract:Rolling contact Bearing life is calculated using Stresses calculated at the surface and in the volume. Surface Stresses account for profile and misalignment as well as asperity deformations. Sub-surface Stresses are calculated beneath the asperities (for defining the life of the surface) and deeper in the volume for calculating the life of the volume. The Stress-life criterion adopted is the Dang Van one in which the local stabilized shear Stress is compared to the material endurance limit defined as a function of the hydrostatic pressure (itself a function of the contact pressure) but also residual Stresses and hoop Stresses (due to fit). A Stress-life exponent c, of the order of 4 (instead of 34/3 in the standard Lundberg and Palmgren model) is used for respecting a local load-life exponent of 10/3 at typical load levels. Life of any circumferential slices of the inner, outer, and roller is defined for obtaining the final Bearing life. Trends showing how the Bearing life varies as a function of the applied Bearing load and Λ ratio (film thickness/RMS roughness height) are given.
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Rolling Bearing Stress Based Life—Part II: Experimental Calibration and Validation
Journal of Tribology-transactions of The Asme, 2012Co-Authors: J. Gnagy, L Houpert, F ChevalierAbstract:The Stress based life model described in Paper I was calibrated using a large database of experimental results from a global quality audit test program as well as special development tests conducted for this validation effort. All tests used in the calibration of the new model were case carburized or through hardened tapered roller Bearings. The initial model comparison to test results showed very good correlation with a median ratio of test life to calculated life very close to one. Higher accuracy of the Stress based model compared to the traditional factor based method was also demonstrated by narrower confidence bands (less data scatter). Validation testing of case carburized tapered roller Bearings as well as through hardened spherical roller Bearings was also conducted under expanded test conditions beyond those utilized in the quality audit test program (i.e., high and low load, high and low λ, imposed misalignment, and heavy inner ring interference fits). Although the median ratio of relative life for the validation testing showed the Stress based method to be conservative and well above one, the Stress based method still showed better accuracy than the traditional factor based method as well as narrower confidence bands for this additional body of experimental data. The conservative results can be explained by use of high quality steel and manufacturing processes in a prototype facility and not series production equipment as was the case with the quality audit database.
Hoan Thong Nguyen - One of the best experts on this subject based on the ideXlab platform.
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A Novel Axial Flux Permanent-Magnet Machine for Flywheel Energy Storage System: Design and Analysis
IEEE Transactions on Industrial Electronics, 2011Co-Authors: Trong Duy Nguyen, King-jet Tseng, Shao Zhang, Hoan Thong NguyenAbstract:This paper presents the design and analysis of a novel axial flux permanent-magnet (AFPM) machine for a flywheel energy storage system (FESS). Its design and control facilitate significant reduction in axial Bearing Stress and losses. Due to the unconventional flux distribution in this machine, a 3-D finite element method was employed for its design and analysis, including its electromagnetic torque and axial force performances. The effects of the rotor PM skew angle on the cogging torque and the axial force have been studied. It is found that an optimum skew angle is effective in reducing the overall cogging torque with negligible effect on the static axial force. The latter is crucial as it can be utilized to minimize the axial Bearing Stress in FESS application. The concept, design, and analysis methodology have been validated by experimental results from an experimental AFPM machine prototype.
Trong Duy Nguyen - One of the best experts on this subject based on the ideXlab platform.
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Sensorless control of a dual-airgap axial flux permanent magnet machine for flywheel energy storage system
IET Electric Power Applications, 2013Co-Authors: Trong Duy NguyenAbstract:This study presents the sensorless vector control of a dual-airgap axial flux permanent magnet (AFPM) machine optimised for use in flywheel energy storage system (FESS) applications. The proposed AFPM machine has two sets of three-phase stator windings but only requires a single power converter to control both electromagnetic torque and axial levitation force. The proper controllability of the latter is crucial as it can be utilised to minimise the vertical Bearing Stress to improve the efficiency of the FESS. The method for controlling the speed and axial displacement of the machine is discussed. An inherent speed sensorless observer is also proposed for speed estimation. The proposed observer eliminates the rotary encoder, which in turn reduces the overall weight and cost of the system while improving its reliability. The effectiveness of the proposed control scheme has been verified by simulations and experiments on a prototype machine.
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A Novel Axial Flux Permanent-Magnet Machine for Flywheel Energy Storage System: Design and Analysis
IEEE Transactions on Industrial Electronics, 2011Co-Authors: Trong Duy Nguyen, King-jet Tseng, Shao Zhang, Hoan Thong NguyenAbstract:This paper presents the design and analysis of a novel axial flux permanent-magnet (AFPM) machine for a flywheel energy storage system (FESS). Its design and control facilitate significant reduction in axial Bearing Stress and losses. Due to the unconventional flux distribution in this machine, a 3-D finite element method was employed for its design and analysis, including its electromagnetic torque and axial force performances. The effects of the rotor PM skew angle on the cogging torque and the axial force have been studied. It is found that an optimum skew angle is effective in reducing the overall cogging torque with negligible effect on the static axial force. The latter is crucial as it can be utilized to minimize the axial Bearing Stress in FESS application. The concept, design, and analysis methodology have been validated by experimental results from an experimental AFPM machine prototype.
Tong Genshu - One of the best experts on this subject based on the ideXlab platform.
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Bearing Stress of crane runway girders under wheel loads
2020Co-Authors: Tong GenshuAbstract:A numerical study was conducted on three-dimensional finite element models to analyze the dispersion of Bearing Stresses of webs in I-shaped crane runway girders under wheel loads.Investigation of the influences of various geometric parameters on the Stress distribution showed that the most important factors influencing the Stress dispersion are the web thickness and the inertia moment of the rail,while the inertia moment of the top flange has only minor influence.The depth and length of the girder and its boundary conditions have negligible effect.Based on the theory of beams on elastic foundation and the numerical results,design equations were proposed to predict the Bearing Stresses on the edge of the web panel and the variation of Bearing Stresses along the depth of the web.
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Revisiting the Bearing Stresses in webs of crane runway girders under wheel loads
Advances in Structural Engineering, 2018Co-Authors: Tong Genshu, Xuan ZejunAbstract:This article revisited the problem of local Bearing Stress in webs of I-section girders supporting overhead cranes. Finite element analysis was carried out to determine the equivalent Bearing lengt...
