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Journal of tribology :Transactions of the ASME |
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Ajouter le résultat dans votre panierA dynamic model for vibration studies of deep groove ball bearings considering single and multiple defects in races / V. N. Patel in Transactions of the ASME . Journal of tribology, Vol. 132 N° 4 (Octobre 2010)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 10 p.
Titre : A dynamic model for vibration studies of deep groove ball bearings considering single and multiple defects in races Type de document : texte imprimé Auteurs : V. N. Patel, Auteur ; N. Tandon, Auteur ; R. K. Pandey, Auteur Année de publication : 2011 Article en page(s) : 10 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Ball bearings Crystal defects Dynamic testing Runge-Kutta methods Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A dynamic model is reported herein for the study of vibrations of deep groove ball bearings having single and multiple defects on surfaces of inner and outer races. Masses of shaft, housing, races, and balls are considered in the modeling. The coupled solution of governing equations of motions is obtained using Runge–Kutta method. The model provides the vibrations of shaft, balls, and housing in time and frequency domains. Computed results from the model are validated with experimental results, which are generated using healthy and defective deep groove ball bearings. Characteristic defect frequencies and its harmonics are broadly investigated using both theoretical and experimental results. Comparison of vibration spectra for the cases having single and two defects on races reveals relatively higher velocity amplitudes with two defects. Good correlations between theoretical and experimental results are observed. Authors believe that this dynamic model can be used with confidence for the study and prediction of vibrations of healthy and defective deep groove ball bearings DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] A dynamic model for vibration studies of deep groove ball bearings considering single and multiple defects in races [texte imprimé] / V. N. Patel, Auteur ; N. Tandon, Auteur ; R. K. Pandey, Auteur . - 2011 . - 10 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 10 p.
Mots-clés : Ball bearings Crystal defects Dynamic testing Runge-Kutta methods Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A dynamic model is reported herein for the study of vibrations of deep groove ball bearings having single and multiple defects on surfaces of inner and outer races. Masses of shaft, housing, races, and balls are considered in the modeling. The coupled solution of governing equations of motions is obtained using Runge–Kutta method. The model provides the vibrations of shaft, balls, and housing in time and frequency domains. Computed results from the model are validated with experimental results, which are generated using healthy and defective deep groove ball bearings. Characteristic defect frequencies and its harmonics are broadly investigated using both theoretical and experimental results. Comparison of vibration spectra for the cases having single and two defects on races reveals relatively higher velocity amplitudes with two defects. Good correlations between theoretical and experimental results are observed. Authors believe that this dynamic model can be used with confidence for the study and prediction of vibrations of healthy and defective deep groove ball bearings DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 07 p.
Titre : Multiple normal loading-unloading cycles of a spherical contact under stick contact condition Type de document : texte imprimé Auteurs : Y. Zait, Auteur ; V. Zolotarevsky, Auteur ; Y. Kligerman, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Elasticity Finite element analysis Hardening Loading Mechanical contact Plasticity Unloading Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The multiple normal loading-unloading process of an elastic-plastic sphere by a rigid flat is analyzed using finite element method for stick contact condition and both kinematic and isotropic hardening models. The behavior of the global contact parameters as well as the stress field within the sphere tip is presented for several loading cycles. It was found that under stick contact condition, secondary plastification occurs even after the second loading cycle and that the hardening model used has little effect on the loading-unloading process. The cyclic loading process gradually converges into elastic shakedown. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Multiple normal loading-unloading cycles of a spherical contact under stick contact condition [texte imprimé] / Y. Zait, Auteur ; V. Zolotarevsky, Auteur ; Y. Kligerman, Auteur . - 2011 . - 07 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 07 p.
Mots-clés : Elasticity Finite element analysis Hardening Loading Mechanical contact Plasticity Unloading Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The multiple normal loading-unloading process of an elastic-plastic sphere by a rigid flat is analyzed using finite element method for stick contact condition and both kinematic and isotropic hardening models. The behavior of the global contact parameters as well as the stress field within the sphere tip is presented for several loading cycles. It was found that under stick contact condition, secondary plastification occurs even after the second loading cycle and that the hardening model used has little effect on the loading-unloading process. The cyclic loading process gradually converges into elastic shakedown. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 11 p.
Titre : Impact of a fixed-length rigid cylinder on an elastic-plastic homogeneous body Type de document : texte imprimé Auteurs : Raja R. Katta, Auteur ; Andreas A. Polycarpou, Auteur Année de publication : 2011 Article en page(s) : 11 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Disc drives Elasticity Finite element analysis Hard discs Impact testing Magnetic storage Plasticity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A contact mechanics (CM) based model of a fixed-length rigid cylinder impacting a homogeneous elastic-plastic homogeneous body was developed and includes an improved method of estimating the residual depth after impact. The nonlinear elastic behavior during unloading was accounted for to develop an improved coefficient of restitution model. The impact model was applied to study a practical case of a cylindrical feature on the slider of a magnetic storage hard disk drive impacting the disk to predict various critical impact contact parameters. The CM model was validated using a plane strain finite element model and it was found that a cylindrical feature with a longer length results in a substantial alleviation of impact damage. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Impact of a fixed-length rigid cylinder on an elastic-plastic homogeneous body [texte imprimé] / Raja R. Katta, Auteur ; Andreas A. Polycarpou, Auteur . - 2011 . - 11 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 11 p.
Mots-clés : Disc drives Elasticity Finite element analysis Hard discs Impact testing Magnetic storage Plasticity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A contact mechanics (CM) based model of a fixed-length rigid cylinder impacting a homogeneous elastic-plastic homogeneous body was developed and includes an improved method of estimating the residual depth after impact. The nonlinear elastic behavior during unloading was accounted for to develop an improved coefficient of restitution model. The impact model was applied to study a practical case of a cylindrical feature on the slider of a magnetic storage hard disk drive impacting the disk to predict various critical impact contact parameters. The CM model was validated using a plane strain finite element model and it was found that a cylindrical feature with a longer length results in a substantial alleviation of impact damage. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 09 p.
Titre : Investigation of inclined planar rough surfaces contact from static to sliding Type de document : texte imprimé Auteurs : Ting Ni, Auteur ; Xi Shi, Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Numerical analysis Sliding friction Surface roughness Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Due to the friction moment, when two flat rough surfaces come to sliding contact or quasi-sliding contact, there is an inclined angle between these two surfaces. A two degree-of-freedom inclined rough surface contact model is presented in this work and the effects of the angular displacement on the friction coefficient, interfacial forces, and interfacial moments for the elastic-plastic planar rough surfaces contact are investigated. The numerical simulations show that both interfacial forces and interfacial moments gain with the increase of the inclined angle while the friction coefficient decreases instead. In addition, for a given sliding mass block system, the effects of that friction coefficient and base sliding speed on the stability of the sliding contact are also discussed. The simulations indicate that a larger friction coefficient and a higher base sliding speed tend to turn over the mass block during the sliding. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Investigation of inclined planar rough surfaces contact from static to sliding [texte imprimé] / Ting Ni, Auteur ; Xi Shi, Auteur . - 2011 . - 09 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 09 p.
Mots-clés : Numerical analysis Sliding friction Surface roughness Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Due to the friction moment, when two flat rough surfaces come to sliding contact or quasi-sliding contact, there is an inclined angle between these two surfaces. A two degree-of-freedom inclined rough surface contact model is presented in this work and the effects of the angular displacement on the friction coefficient, interfacial forces, and interfacial moments for the elastic-plastic planar rough surfaces contact are investigated. The numerical simulations show that both interfacial forces and interfacial moments gain with the increase of the inclined angle while the friction coefficient decreases instead. In addition, for a given sliding mass block system, the effects of that friction coefficient and base sliding speed on the stability of the sliding contact are also discussed. The simulations indicate that a larger friction coefficient and a higher base sliding speed tend to turn over the mass block during the sliding. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 12 p.
Titre : An approach for modeling material grain structure in investigations of hertzian subsurface stresses and rolling contact fatigue Type de document : texte imprimé Auteurs : Nick Weinzapfel, Auteur ; Farshid Sadeghi, Auteur ; Vasilios Bakolas, Auteur Année de publication : 2011 Article en page(s) : 12 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Computational geometry Crystal microstructure Fatigue Finite element analysis Internal stresses Mechanical contact Rolling bearings Rolling friction Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The continuum theory of elasticity and/or homogeneously discretized finite element models have been commonly used to investigate and analyze subsurface stresses in Hertzian contacts. These approaches, however, do not effectively capture the influence of the random microstructure topology on subsurface stress distributions in Hertzian contacts. In this paper, a finite element model for analyzing subsurface stresses in an elastic half-space subjected to a general Hertzian contact load with explicit consideration of the material microstructure topology is presented. The random internal geometry of polycrystalline microstructures is modeled using a 3D Voronoi tessellation, where each Voronoi cell represents a distinct material grain. The grains are then meshed using finite elements, and an algorithm was developed to eliminate poorly shaped elements resulting from “near degeneracy” in the Voronoi tessellations. Hertzian point and line contacts loads are applied as distributed surface loads, and the model's response is evaluated with commercial finite element software ABAQUS. Internal stress results obtained from the current model compare well with analytical solutions from theory of elasticity. The influence of the internal microstructure topology on the subsurface stresses is demonstrated by analyzing the model's response to an over rolling element using a critical plane approach. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] An approach for modeling material grain structure in investigations of hertzian subsurface stresses and rolling contact fatigue [texte imprimé] / Nick Weinzapfel, Auteur ; Farshid Sadeghi, Auteur ; Vasilios Bakolas, Auteur . - 2011 . - 12 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 12 p.
Mots-clés : Computational geometry Crystal microstructure Fatigue Finite element analysis Internal stresses Mechanical contact Rolling bearings Rolling friction Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The continuum theory of elasticity and/or homogeneously discretized finite element models have been commonly used to investigate and analyze subsurface stresses in Hertzian contacts. These approaches, however, do not effectively capture the influence of the random microstructure topology on subsurface stress distributions in Hertzian contacts. In this paper, a finite element model for analyzing subsurface stresses in an elastic half-space subjected to a general Hertzian contact load with explicit consideration of the material microstructure topology is presented. The random internal geometry of polycrystalline microstructures is modeled using a 3D Voronoi tessellation, where each Voronoi cell represents a distinct material grain. The grains are then meshed using finite elements, and an algorithm was developed to eliminate poorly shaped elements resulting from “near degeneracy” in the Voronoi tessellations. Hertzian point and line contacts loads are applied as distributed surface loads, and the model's response is evaluated with commercial finite element software ABAQUS. Internal stress results obtained from the current model compare well with analytical solutions from theory of elasticity. The influence of the internal microstructure topology on the subsurface stresses is demonstrated by analyzing the model's response to an over rolling element using a critical plane approach. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 13 p.
Titre : Visco-elastohydrodynamic model of a hydraulic rod seal during transient operation Type de document : texte imprimé Auteurs : Azam Thatte, Auteur ; Richard F. Salant, Auteur Année de publication : 2011 Article en page(s) : 13 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Cavitation Deformation Finite element analysis Finite volume methods Friction Hydraulic systems Hydrodynamics Poiseuille flow Rods (structures) Sealing materials Viscoelasticity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A visco-elastohydrodynamic model of a hydraulic rod seal during transient operation has been developed. The model includes analyses of the macro- and microscale deformation mechanics and contact mechanics, and the microscale fluid mechanics. Viscoelasticity enters the analysis through the deformation mechanics and through the contact mechanics. A hybrid finite element-finite volume computational framework is developed to solve the highly coupled governing equations. Viscoelasticity is seen to affect the leakage and friction characteristics of the seal through its effects on the changing fluid pressure and contact pressure distributions as the rod velocity and sealed pressure change during a cycle. Compared with purely elastic behavior, viscoelasticity increases the fluid pressure and the contact pressure significantly in the sealing region closest to the sealed end, shifts the fluid pressure peaks away from the sealed end during the instroke, and enhances the cavitation during the outstroke. It results in thicker fluid films and produces a significant increase in the Poiseuille flow during the instroke. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Visco-elastohydrodynamic model of a hydraulic rod seal during transient operation [texte imprimé] / Azam Thatte, Auteur ; Richard F. Salant, Auteur . - 2011 . - 13 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 13 p.
Mots-clés : Cavitation Deformation Finite element analysis Finite volume methods Friction Hydraulic systems Hydrodynamics Poiseuille flow Rods (structures) Sealing materials Viscoelasticity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A visco-elastohydrodynamic model of a hydraulic rod seal during transient operation has been developed. The model includes analyses of the macro- and microscale deformation mechanics and contact mechanics, and the microscale fluid mechanics. Viscoelasticity enters the analysis through the deformation mechanics and through the contact mechanics. A hybrid finite element-finite volume computational framework is developed to solve the highly coupled governing equations. Viscoelasticity is seen to affect the leakage and friction characteristics of the seal through its effects on the changing fluid pressure and contact pressure distributions as the rod velocity and sealed pressure change during a cycle. Compared with purely elastic behavior, viscoelasticity increases the fluid pressure and the contact pressure significantly in the sealing region closest to the sealed end, shifts the fluid pressure peaks away from the sealed end during the instroke, and enhances the cavitation during the outstroke. It results in thicker fluid films and produces a significant increase in the Poiseuille flow during the instroke. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010)
Titre : Investigation of temperature effects on cavitation erosion behavior based on analysis of erosion particles Type de document : texte imprimé Auteurs : B. Saleh, Auteur ; A. Abouel-Kasem, Auteur ; A. Ezz El-Deen, Auteur Année de publication : 2011 Note générale : Tribology Langues : Anglais (eng) Mots-clés : Aluminium Fatigue Particle size Scanning electron microscopy Wear Wear testing Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The effect of temperature on the wear particles produced by vibratory cavitation erosion tests on Al-99.92 in distilled water was analyzed. Scanning electron microscope images of wear particles were obtained, forming a database for further analysis. This study showed that the variation of average particle size with temperature was very much similar to the variation of weight loss with temperature. The average particle size was maximum at 40°C. It was also observed that the average particle size was time dependent. The particle's morphology features revealed that the predominant erosion mechanism was fatigue failure, irrespective of the temperature. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Investigation of temperature effects on cavitation erosion behavior based on analysis of erosion particles [texte imprimé] / B. Saleh, Auteur ; A. Abouel-Kasem, Auteur ; A. Ezz El-Deen, Auteur . - 2011.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010)
Mots-clés : Aluminium Fatigue Particle size Scanning electron microscopy Wear Wear testing Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The effect of temperature on the wear particles produced by vibratory cavitation erosion tests on Al-99.92 in distilled water was analyzed. Scanning electron microscope images of wear particles were obtained, forming a database for further analysis. This study showed that the variation of average particle size with temperature was very much similar to the variation of weight loss with temperature. The average particle size was maximum at 40°C. It was also observed that the average particle size was time dependent. The particle's morphology features revealed that the predominant erosion mechanism was fatigue failure, irrespective of the temperature. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 09 p.
Titre : Effects of some solid lubricants suspended in oil toward controlling the wear performance of a cast iron Type de document : texte imprimé Auteurs : B. K. Prasad, Auteur ; S. Rathod, Auteur ; M. S. Yadav, Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Cast iron Lubricating oils Lubrication Sliding friction Suspensions Wear Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The present investigation deals with the examination of the sliding wear response of a gray cast iron in oil lubricated condition over a range of applied pressure. The composition of the oil lubricant was changed by adding 5.26 wt % solid lubricant particles. The solid lubricants used were graphite, talc, MoS2, and lead. The observed wear response of the samples has been substantiated through the characteristics of wear surfaces, subsurface regions, and debris particles and discussed in terms of specific response of different microconstituents, such as ferrite, pearlite, and graphite present therein. Operating wear mechanisms were assessed through the observed features of wear surfaces, subsurface regions, and debris. The wear rate increased with applied pressure. The slope of the wear rate versus pressure plots was low up to a critical pressure. This was followed by a sudden rise in the slope at higher pressures irrespective of the test environment. The frictional heating was affected by pressure in a manner practically identical to that of the wear rate. The presence of graphite, MoS2, and lead in the oil led to a substantial decrease in the wear rate and severity of frictional heating. The oil plus lead lubricant mixture was observed to offer best results in terms of reduced wear rate and lower frictional heating. This was followed by the ones containing graphite and MoS2 while talc caused the wear performance of the samples to deteriorate over that of the bare oil. However, the severity of frictional heating decreased in general in the oil containing solid lubricant particles. Seizure brought about high frictional heating and wear rate. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Effects of some solid lubricants suspended in oil toward controlling the wear performance of a cast iron [texte imprimé] / B. K. Prasad, Auteur ; S. Rathod, Auteur ; M. S. Yadav, Auteur . - 2011 . - 09 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 09 p.
Mots-clés : Cast iron Lubricating oils Lubrication Sliding friction Suspensions Wear Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The present investigation deals with the examination of the sliding wear response of a gray cast iron in oil lubricated condition over a range of applied pressure. The composition of the oil lubricant was changed by adding 5.26 wt % solid lubricant particles. The solid lubricants used were graphite, talc, MoS2, and lead. The observed wear response of the samples has been substantiated through the characteristics of wear surfaces, subsurface regions, and debris particles and discussed in terms of specific response of different microconstituents, such as ferrite, pearlite, and graphite present therein. Operating wear mechanisms were assessed through the observed features of wear surfaces, subsurface regions, and debris. The wear rate increased with applied pressure. The slope of the wear rate versus pressure plots was low up to a critical pressure. This was followed by a sudden rise in the slope at higher pressures irrespective of the test environment. The frictional heating was affected by pressure in a manner practically identical to that of the wear rate. The presence of graphite, MoS2, and lead in the oil led to a substantial decrease in the wear rate and severity of frictional heating. The oil plus lead lubricant mixture was observed to offer best results in terms of reduced wear rate and lower frictional heating. This was followed by the ones containing graphite and MoS2 while talc caused the wear performance of the samples to deteriorate over that of the bare oil. However, the severity of frictional heating decreased in general in the oil containing solid lubricant particles. Seizure brought about high frictional heating and wear rate. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Titre : Wear characteristics of NiTi/Al6061 short fiber metal matrix composite reinforced with SiC particulates Type de document : texte imprimé Auteurs : Ozgen Akalin, Auteur ; K. Vefa Ezirmik, Auteur ; Mustafa Urgen, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Fibre reinforced composites Martensitic steel Nickel alloys Scanning electron microscopy Silicon compounds Sintering Titanium alloys Tribology Wear resistance Wear testing Wide band gap semiconductors Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Wear characteristics of Al6061 composites, reinforced with short NiTi fibers, were investigated. The NiTi/Al6061 composite samples were fabricated using pressure-assisted sintering process in ambient air where the NiTi fibers are aligned unidirectional in the Al matrix. In addition, NiTi/Al6061 composite with 5 wt % SiC particulates and monolithic Al6061 and Al6061 with 5 wt % SiC particulates were processed in similar conditions. The wear tests were performed using a reciprocating tribometer in ball-on-flat configuration where the counterbody material was martensitic steel. The effects of fiber isotropy and SiC reinforcements on wear resistance were experimentally investigated in dry sliding. Wear properties of the samples were studied using an optical profiler and a scanning electron microscope analysis. The results showed that transverse NiTi fibers improve the wear resistance significantly. Samples with transverse fiber orientation show mostly abrasive wear, whereas, monolithic and parallel samples show adhesive wear mechanism. In addition, SiC reinforcements improve the wear resistance of the composite and the monolithic samples. Since the Al6061 matrix material is smeared onto NiTi fibers in a short period, all composite samples show similar frictional characteristics after certain period of running in dry sliding. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Wear characteristics of NiTi/Al6061 short fiber metal matrix composite reinforced with SiC particulates [texte imprimé] / Ozgen Akalin, Auteur ; K. Vefa Ezirmik, Auteur ; Mustafa Urgen, Auteur . - 2011 . - 06 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Mots-clés : Fibre reinforced composites Martensitic steel Nickel alloys Scanning electron microscopy Silicon compounds Sintering Titanium alloys Tribology Wear resistance Wear testing Wide band gap semiconductors Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Wear characteristics of Al6061 composites, reinforced with short NiTi fibers, were investigated. The NiTi/Al6061 composite samples were fabricated using pressure-assisted sintering process in ambient air where the NiTi fibers are aligned unidirectional in the Al matrix. In addition, NiTi/Al6061 composite with 5 wt % SiC particulates and monolithic Al6061 and Al6061 with 5 wt % SiC particulates were processed in similar conditions. The wear tests were performed using a reciprocating tribometer in ball-on-flat configuration where the counterbody material was martensitic steel. The effects of fiber isotropy and SiC reinforcements on wear resistance were experimentally investigated in dry sliding. Wear properties of the samples were studied using an optical profiler and a scanning electron microscope analysis. The results showed that transverse NiTi fibers improve the wear resistance significantly. Samples with transverse fiber orientation show mostly abrasive wear, whereas, monolithic and parallel samples show adhesive wear mechanism. In addition, SiC reinforcements improve the wear resistance of the composite and the monolithic samples. Since the Al6061 matrix material is smeared onto NiTi fibers in a short period, all composite samples show similar frictional characteristics after certain period of running in dry sliding. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 05 p.
Titre : Does thermal conductivity play a role in sliding wear of metals in cryogenic environment? Type de document : texte imprimé Auteurs : Bikramjit Basu, Auteur ; Amartya Mukhopadhyay, Auteur ; Ankit Mishra, Auteur Année de publication : 2011 Article en page(s) : 05 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Abrasion Boiling point Copper Hardness Low-temperature techniques Machine bearings Mechanical contact Sliding friction Steel Thermal conductivity Titanium Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The thermal conductivity of a metallic test piece is one of the principal parameters that influence the temperature buildup at tribocontacts and this normally plays an important role in the unlubricated dry sliding wear of metallic materials. It is, however, not clear whether thermal conductivity is an equally important parameter in the case of wear of metals at cryogenic temperatures, in particular, at liquid nitrogen temperature (LN2) of −196°C. In order to assess the influence of such a physical property of selected nonferrous metals on their tribological behavior in the LN2 environment, we have studied the friction and wear properties of high purity copper (Cu) and titanium (Ti) against the bearing grade steel. These two materials have been processed to produce samples of comparable hardness that have widely different thermal conductivities at room temperature and at test temperature. Wear tests were conducted at three different sliding speeds (0.89 m/s, 1.11 m/s, and 1.34 m/s) under 10 N load, and the friction and wear data were compared. Ti exhibited an order of magnitude higher wear rate (~10−3 mm3/N m) as compared with Cu in identical test conditions. While evidences of abrasive wear and adhesive wear, without any oxidative wear, were found in worn Cu surfaces, worn Ti surfaces showed evidences of significant oxidative wear and mechanical damage of tribolayers. Higher wear rate in Ti appeared to be a result of oxidative wear of Ti, which seemed to be driven by the depletion of LN2 blanket at the tribocontacts under the influence of high flash temperature (14–76°C) as compared with the boiling temperature of LN2 (−196°C). These results demonstrate that the materials with similar hardness subjected to identical LN2 wear test conditions can have significantly different wear rates because of the difference in the flash temperatures, which depend on the thermal conductivity of the test pieces. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Does thermal conductivity play a role in sliding wear of metals in cryogenic environment? [texte imprimé] / Bikramjit Basu, Auteur ; Amartya Mukhopadhyay, Auteur ; Ankit Mishra, Auteur . - 2011 . - 05 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 05 p.
Mots-clés : Abrasion Boiling point Copper Hardness Low-temperature techniques Machine bearings Mechanical contact Sliding friction Steel Thermal conductivity Titanium Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The thermal conductivity of a metallic test piece is one of the principal parameters that influence the temperature buildup at tribocontacts and this normally plays an important role in the unlubricated dry sliding wear of metallic materials. It is, however, not clear whether thermal conductivity is an equally important parameter in the case of wear of metals at cryogenic temperatures, in particular, at liquid nitrogen temperature (LN2) of −196°C. In order to assess the influence of such a physical property of selected nonferrous metals on their tribological behavior in the LN2 environment, we have studied the friction and wear properties of high purity copper (Cu) and titanium (Ti) against the bearing grade steel. These two materials have been processed to produce samples of comparable hardness that have widely different thermal conductivities at room temperature and at test temperature. Wear tests were conducted at three different sliding speeds (0.89 m/s, 1.11 m/s, and 1.34 m/s) under 10 N load, and the friction and wear data were compared. Ti exhibited an order of magnitude higher wear rate (~10−3 mm3/N m) as compared with Cu in identical test conditions. While evidences of abrasive wear and adhesive wear, without any oxidative wear, were found in worn Cu surfaces, worn Ti surfaces showed evidences of significant oxidative wear and mechanical damage of tribolayers. Higher wear rate in Ti appeared to be a result of oxidative wear of Ti, which seemed to be driven by the depletion of LN2 blanket at the tribocontacts under the influence of high flash temperature (14–76°C) as compared with the boiling temperature of LN2 (−196°C). These results demonstrate that the materials with similar hardness subjected to identical LN2 wear test conditions can have significantly different wear rates because of the difference in the flash temperatures, which depend on the thermal conductivity of the test pieces. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Titre : Coffee stain ring effect and nonuniform material removal in chemical mechanical polishing Type de document : texte imprimé Auteurs : Jianguo Xin, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Chemical mechanical polishing Drops Evaporation Flow Solvent effects Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : When a drop of coffee dries on the counter-top, it leaves a dense, ringlike stain along its perimeter. Solids immersed in a drying drop will migrate toward the edge of the drop and form a solid ring. Such phenomena create ringlike stains and happen for a wide variety of surfaces, solvents, and solutes. It is referred to as the coffee stain ring effect. The phenomenon is caused by the outward microfluidic flow of the solute within the drop, which is driven by the evaporation of solvent. We show that the mechanism for the ring effect contributes to the nonuniform material removal in chemical mechanical polishing (CMP), specifically, at edges of blanket wafers causing the edge effect or at edges and corners of protrusive features on patterned wafers inducing the doming effect; metal dishing and dielectric erosion. By controlling the evaporation profile of the solvent in the slurry layer between the wafer surface and the polishing pad, such as making grooves or embedding the abrasive particles on the pad, or delivering the slurry from the bottom of the pad, one can improve the uniformity of material removal during the CMP process. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Coffee stain ring effect and nonuniform material removal in chemical mechanical polishing [texte imprimé] / Jianguo Xin, Auteur . - 2011 . - 06 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Mots-clés : Chemical mechanical polishing Drops Evaporation Flow Solvent effects Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : When a drop of coffee dries on the counter-top, it leaves a dense, ringlike stain along its perimeter. Solids immersed in a drying drop will migrate toward the edge of the drop and form a solid ring. Such phenomena create ringlike stains and happen for a wide variety of surfaces, solvents, and solutes. It is referred to as the coffee stain ring effect. The phenomenon is caused by the outward microfluidic flow of the solute within the drop, which is driven by the evaporation of solvent. We show that the mechanism for the ring effect contributes to the nonuniform material removal in chemical mechanical polishing (CMP), specifically, at edges of blanket wafers causing the edge effect or at edges and corners of protrusive features on patterned wafers inducing the doming effect; metal dishing and dielectric erosion. By controlling the evaporation profile of the solvent in the slurry layer between the wafer surface and the polishing pad, such as making grooves or embedding the abrasive particles on the pad, or delivering the slurry from the bottom of the pad, one can improve the uniformity of material removal during the CMP process. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 11 p.
Titre : Condition monitoring of molybdenum disulphide coated thrust ball bearings using time-frequency signal analysis Type de document : texte imprimé Auteurs : Ali Kahirdeh, Auteur ; M. M. Khonsari, Auteur Année de publication : 2011 Article en page(s) : 11 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Ball bearings Condition monitoring Friction Lubricants Molybdenum compounds Time-frequency analysis Wear Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A method for detection of wear in thrust ball bearings coated with molybdenum disulphide (MoS2) is presented. It employs an energy feature obtained from time-frequency representation of the vibration signal. Extensive experimental studies are conducted to verify the efficacy of the proposed method for fault diagnosis of MoS2 coating. These experiments are conducted under both oscillatory and unidirectional motions. The results of vibrations are corroborated with the friction coefficient from the onset of the motion until failure develops. Through monitoring of the energy in time-frequency domain as well as the coefficient of friction, three stages of coating life are identified. They are healthy period, developing damage, and failure. It is shown that the energy feature can detect whenever wear and damage appear and solid lubricant loses its lubrication capabilities. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Condition monitoring of molybdenum disulphide coated thrust ball bearings using time-frequency signal analysis [texte imprimé] / Ali Kahirdeh, Auteur ; M. M. Khonsari, Auteur . - 2011 . - 11 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 11 p.
Mots-clés : Ball bearings Condition monitoring Friction Lubricants Molybdenum compounds Time-frequency analysis Wear Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A method for detection of wear in thrust ball bearings coated with molybdenum disulphide (MoS2) is presented. It employs an energy feature obtained from time-frequency representation of the vibration signal. Extensive experimental studies are conducted to verify the efficacy of the proposed method for fault diagnosis of MoS2 coating. These experiments are conducted under both oscillatory and unidirectional motions. The results of vibrations are corroborated with the friction coefficient from the onset of the motion until failure develops. Through monitoring of the energy in time-frequency domain as well as the coefficient of friction, three stages of coating life are identified. They are healthy period, developing damage, and failure. It is shown that the energy feature can detect whenever wear and damage appear and solid lubricant loses its lubrication capabilities. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 11 p.
Titre : A comparative thermal analysis of slot-entry and hole-entry hybrid journal bearings lubricated with non-newtonian lubricant Type de document : texte imprimé Auteurs : H. C. Garg, Auteur ; Vijay Kumar, Auteur ; H. B. Sharda, Auteur Année de publication : 2011 Article en page(s) : 11 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Finite element analysis Iterative methods Lubricants Machine bearings Non-Newtonian flow Orifices (mechanical) Thermal analysis Viscosity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The effect of viscosity variation due to temperature rise and non-Newtonian behavior of the lubricant on the performance of hole-entry and slot-entry hybrid journal bearings system is the focus of this investigation. The performance characteristics of nonrecessed hybrid journal bearings operating with different flow controlling devices, i.e., constant flow valve, capillary, orifice, and slot restrictors, have been compared. Finite element method has been used to solve the Reynolds equation governing the flow of lubricant in the bearing clearance space along with the restrictor flow equation, energy equation and conduction equation using suitable iterative technique. The non-Newtonian lubricant has been assumed to follow the cubic shear stress law. The results indicate that variation in viscosity due to rise in temperature and non-Newtonian behavior of the lubricant affects the performance of nonrecessed hybrid journal bearing system quite significantly. The results further indicate that bearing performance can be improved by selecting a particular bearing configuration in conjunction with a suitable compensating device. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] A comparative thermal analysis of slot-entry and hole-entry hybrid journal bearings lubricated with non-newtonian lubricant [texte imprimé] / H. C. Garg, Auteur ; Vijay Kumar, Auteur ; H. B. Sharda, Auteur . - 2011 . - 11 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 11 p.
Mots-clés : Finite element analysis Iterative methods Lubricants Machine bearings Non-Newtonian flow Orifices (mechanical) Thermal analysis Viscosity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The effect of viscosity variation due to temperature rise and non-Newtonian behavior of the lubricant on the performance of hole-entry and slot-entry hybrid journal bearings system is the focus of this investigation. The performance characteristics of nonrecessed hybrid journal bearings operating with different flow controlling devices, i.e., constant flow valve, capillary, orifice, and slot restrictors, have been compared. Finite element method has been used to solve the Reynolds equation governing the flow of lubricant in the bearing clearance space along with the restrictor flow equation, energy equation and conduction equation using suitable iterative technique. The non-Newtonian lubricant has been assumed to follow the cubic shear stress law. The results indicate that variation in viscosity due to rise in temperature and non-Newtonian behavior of the lubricant affects the performance of nonrecessed hybrid journal bearing system quite significantly. The results further indicate that bearing performance can be improved by selecting a particular bearing configuration in conjunction with a suitable compensating device. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 12 p.
Titre : A mass-conserving complementarity formulation to study lubricant films in the presence of cavitation Type de document : texte imprimé Auteurs : Matteo Giacopini, Auteur ; Mark T. Fowell, Auteur ; Daniele Dini, Auteur Année de publication : 2011 Article en page(s) : 12 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Cavitation Complementarity Film flow Lubricants Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A new mass-conserving formulation of the Reynolds equation is developed using the concept of complementarity. This new method overcomes the drawbacks previously associated with the use of such complementarity formulations for the solution of cavitation problems in which reformation of the liquid film occurs. Validation against a number of analytical and semi-analytical formulations, for a variety of problems including textured bearings and squeeze film dampers, is performed. The current formulation is shown to be in very good agreement with existing analytical and numerical mass-conserving solutions. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] A mass-conserving complementarity formulation to study lubricant films in the presence of cavitation [texte imprimé] / Matteo Giacopini, Auteur ; Mark T. Fowell, Auteur ; Daniele Dini, Auteur . - 2011 . - 12 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 12 p.
Mots-clés : Cavitation Complementarity Film flow Lubricants Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A new mass-conserving formulation of the Reynolds equation is developed using the concept of complementarity. This new method overcomes the drawbacks previously associated with the use of such complementarity formulations for the solution of cavitation problems in which reformation of the liquid film occurs. Validation against a number of analytical and semi-analytical formulations, for a variety of problems including textured bearings and squeeze film dampers, is performed. The current formulation is shown to be in very good agreement with existing analytical and numerical mass-conserving solutions. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Titre : A baseline theory for the design of oil-lubricated centrally pivoted plane-pad thrust bearings Type de document : texte imprimé Auteurs : L. Chang, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Friction Lubrication Machine bearings Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A baseline theory is developed in this paper for the design of oil-lubricated centrally pivoted plane-pad thrust bearings. By focusing on the hydrodynamics generated by the viscosity-temperature effects of the lubricating oil, a mathematical model is derived with a single dimensionless parameter Wth. The nominal value of Wth is 0.1 for typical pad bearings in current industrial practice. The theory suggests two important design calculations for centrally pivoted plane-pad bearings: (1) The minimum oil film thickness in the bearing is about 0.65 of the film thickness determined using the classical isothermal lubrication theory with the pad pivoted at the maximum-load optimum location. Thus, by setting the film thickness to 1.54 times the design requirement, one may carry out design selections and calculations using the classical theory. (2) The friction in the bearing is about 1.7 times the value determined using the classical theory at the maximum-load optimum condition and with the film thickness equal to the design requirement. Thus, one may also use the classical theory to meaningfully calculate the friction and power loss in the centrally pivoted plane-pad bearing systems. The theory is developed based on fundamental lubrication science, order of magnitude analyses of the assumptions, and supporting evidence from numerical literature case studies. It would be a conservative baseline theory for the bearing design as other complicated and/or incidental mechanisms would help provide a design factor of safety. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] A baseline theory for the design of oil-lubricated centrally pivoted plane-pad thrust bearings [texte imprimé] / L. Chang, Auteur . - 2011 . - 06 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Mots-clés : Friction Lubrication Machine bearings Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : A baseline theory is developed in this paper for the design of oil-lubricated centrally pivoted plane-pad thrust bearings. By focusing on the hydrodynamics generated by the viscosity-temperature effects of the lubricating oil, a mathematical model is derived with a single dimensionless parameter Wth. The nominal value of Wth is 0.1 for typical pad bearings in current industrial practice. The theory suggests two important design calculations for centrally pivoted plane-pad bearings: (1) The minimum oil film thickness in the bearing is about 0.65 of the film thickness determined using the classical isothermal lubrication theory with the pad pivoted at the maximum-load optimum location. Thus, by setting the film thickness to 1.54 times the design requirement, one may carry out design selections and calculations using the classical theory. (2) The friction in the bearing is about 1.7 times the value determined using the classical theory at the maximum-load optimum condition and with the film thickness equal to the design requirement. Thus, one may also use the classical theory to meaningfully calculate the friction and power loss in the centrally pivoted plane-pad bearing systems. The theory is developed based on fundamental lubrication science, order of magnitude analyses of the assumptions, and supporting evidence from numerical literature case studies. It would be a conservative baseline theory for the bearing design as other complicated and/or incidental mechanisms would help provide a design factor of safety. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 12 p.
Titre : A study of worn hybrid journal bearing system with different recess shapes under turbulent regime Type de document : texte imprimé Auteurs : E. Rajasekhar Nicodemus, Auteur ; Sharma, Satish C., Auteur Année de publication : 2011 Article en page(s) : 12 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Abrasion Elastic constants Finite element analysis Lubrication Machine bearings Turbulence Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The objective of the present paper is to study analytically the influence of wear on the performance of a capillary-compensated, four-pocket, hybrid journal bearing system operating in a turbulent regime by considering various geometric shapes of recess. The present study deals with bearings having four different geometric shapes of recess, i.e., square, circular, elliptical, and triangular recessed bearings. The wear on the bearing surface is modeled using Dufrane's abrasive wear model. The Reynolds equation based on Constantinescu's turbulent lubrication theory has been solved using finite element method along with a restrictor flow equation as a constraint together with appropriate boundary conditions. The numerically simulated results have been presented for a wide range of nondimensional external loads, wear depth parameters, and Reynolds numbers. The numerically simulated results suggest that the combined influence of wear, turbulence, and geometric shape of recess significantly affects the bearing performance. It has been observed that a triangular recessed bearing provides a greater value of minimum fluid film thickness when operating in a turbulent regime. It is also noticed that direct fluid film stiffness coefficients get reduced significantly when bearings operate in a turbulent regime compared with a laminar regime. Further, it is observed that from the viewpoint of fluid film stiffness, a square recessed bearing is found to be most suitable when operating in a turbulent regime. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] A study of worn hybrid journal bearing system with different recess shapes under turbulent regime [texte imprimé] / E. Rajasekhar Nicodemus, Auteur ; Sharma, Satish C., Auteur . - 2011 . - 12 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 12 p.
Mots-clés : Abrasion Elastic constants Finite element analysis Lubrication Machine bearings Turbulence Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The objective of the present paper is to study analytically the influence of wear on the performance of a capillary-compensated, four-pocket, hybrid journal bearing system operating in a turbulent regime by considering various geometric shapes of recess. The present study deals with bearings having four different geometric shapes of recess, i.e., square, circular, elliptical, and triangular recessed bearings. The wear on the bearing surface is modeled using Dufrane's abrasive wear model. The Reynolds equation based on Constantinescu's turbulent lubrication theory has been solved using finite element method along with a restrictor flow equation as a constraint together with appropriate boundary conditions. The numerically simulated results have been presented for a wide range of nondimensional external loads, wear depth parameters, and Reynolds numbers. The numerically simulated results suggest that the combined influence of wear, turbulence, and geometric shape of recess significantly affects the bearing performance. It has been observed that a triangular recessed bearing provides a greater value of minimum fluid film thickness when operating in a turbulent regime. It is also noticed that direct fluid film stiffness coefficients get reduced significantly when bearings operate in a turbulent regime compared with a laminar regime. Further, it is observed that from the viewpoint of fluid film stiffness, a square recessed bearing is found to be most suitable when operating in a turbulent regime. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 16 p.
Titre : Theoretical modeling for microgrooved journal bearings under mixed lubrication Type de document : texte imprimé Auteurs : Katsuhiro Ashihara, Auteur ; Hiromu Hashimoto, Auteur Année de publication : 2011 Article en page(s) : 16 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Elastic deformation Friction Lubrication Machine bearings Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In designing of engine bearings for automobiles, we need to establish a mixed lubrication model that considers the solid-to-solid contact between journal surfaces and bearing surfaces with microgroove. However, as far as we know, there is no literature treating such problems. This paper describes theoretical modeling for microgrooved bearings under the mixed lubrication conditions with experimental verifications and prediction of performance in the actual engine bearings. In this modeling, a sectional shape of the microgrooved bearing was approximated to be a circular sectional shape. Contact pressure between the journal surfaces and the bearing surfaces with microgroove was calculated using the Hertzian contact model and the effects of elastic deformation of bearing surface due to hydrodynamic and contact pressures were considered. A numerical calculation model was developed to predict bearing performance under the mixed lubrication condition in microgrooved journal bearings. Oil film thickness distributions, hydrodynamic and contact pressure distributions, and real contact area between the journal surfaces and the bearing surfaces with microgroove were obtained simultaneously by the theoretical model. Moreover, friction coefficients under mixed lubrication conditions were determined by the theoretical model and the calculated results were compared with experimental results using test rig. The calculated results successfully agreed with the experimental results and the applicability of the model was verified. Moreover, the model was applied to predict the performance of engine bearings. In the numerical results, real contact area occurred relative widely under low-speed conditions when engine was started but friction loss was not excessive because of low shearing velocity. On the other hand, under high-speed engine conditions, the friction loss was large in spite of narrow real contact area because of high shearing velocity. Under both low-speed and high-speed conditions, the real contacts will occur severely at the edge of the bearing in the axial direction and at the bearing angles from 50 deg to 110 deg in circumferential direction. In addition, an appropriate design of the microgrooved bearing was examined under mixed lubrication conditions. In the design of the microgrooves, a cooling effect and an enough amount of oil flow to the contact area are needed. As the results from parametric studies using present theoretical model, an influence of the depth of the microgroove was the largest on the cooling effect and the enough amount of oil flow. In the case of typical operation condition, it was found that 1.0 µm of the groove depth was the most appropriate. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Theoretical modeling for microgrooved journal bearings under mixed lubrication [texte imprimé] / Katsuhiro Ashihara, Auteur ; Hiromu Hashimoto, Auteur . - 2011 . - 16 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 16 p.
Mots-clés : Elastic deformation Friction Lubrication Machine bearings Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In designing of engine bearings for automobiles, we need to establish a mixed lubrication model that considers the solid-to-solid contact between journal surfaces and bearing surfaces with microgroove. However, as far as we know, there is no literature treating such problems. This paper describes theoretical modeling for microgrooved bearings under the mixed lubrication conditions with experimental verifications and prediction of performance in the actual engine bearings. In this modeling, a sectional shape of the microgrooved bearing was approximated to be a circular sectional shape. Contact pressure between the journal surfaces and the bearing surfaces with microgroove was calculated using the Hertzian contact model and the effects of elastic deformation of bearing surface due to hydrodynamic and contact pressures were considered. A numerical calculation model was developed to predict bearing performance under the mixed lubrication condition in microgrooved journal bearings. Oil film thickness distributions, hydrodynamic and contact pressure distributions, and real contact area between the journal surfaces and the bearing surfaces with microgroove were obtained simultaneously by the theoretical model. Moreover, friction coefficients under mixed lubrication conditions were determined by the theoretical model and the calculated results were compared with experimental results using test rig. The calculated results successfully agreed with the experimental results and the applicability of the model was verified. Moreover, the model was applied to predict the performance of engine bearings. In the numerical results, real contact area occurred relative widely under low-speed conditions when engine was started but friction loss was not excessive because of low shearing velocity. On the other hand, under high-speed engine conditions, the friction loss was large in spite of narrow real contact area because of high shearing velocity. Under both low-speed and high-speed conditions, the real contacts will occur severely at the edge of the bearing in the axial direction and at the bearing angles from 50 deg to 110 deg in circumferential direction. In addition, an appropriate design of the microgrooved bearing was examined under mixed lubrication conditions. In the design of the microgrooves, a cooling effect and an enough amount of oil flow to the contact area are needed. As the results from parametric studies using present theoretical model, an influence of the depth of the microgroove was the largest on the cooling effect and the enough amount of oil flow. In the case of typical operation condition, it was found that 1.0 µm of the groove depth was the most appropriate. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Titre : Pure squeeze motion in a magneto-elastohydrodynamic lubricated spherical conjunction Type de document : texte imprimé Auteurs : Li-Ming Chu, Auteur ; Jaw-Ren Lin, Auteur ; Wang-Long Li, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Lubrication Magnetic fields Magnetohydrodynamics Viscosity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The pure squeeze magneto-elastohydrodynamic lubrication (MEHL) motion of circular contacts with an electrically conducting fluid in the presence of a transverse magnetic field is explored under constant load condition. The differences between classical elastohydrodynamic lubrication and MEHL are discussed. The results reveal that the effect of an externally applied magnetic field is equivalent to enhancing effective lubricant viscosity. Therefore, as the Hartmann number increases, the enhancing effect becomes more obvious. Furthermore, the transient pressure profiles, film shapes, normal squeeze velocities, and effective viscosity during the pure squeeze process under various operating conditions are discussed. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Pure squeeze motion in a magneto-elastohydrodynamic lubricated spherical conjunction [texte imprimé] / Li-Ming Chu, Auteur ; Jaw-Ren Lin, Auteur ; Wang-Long Li, Auteur . - 2011 . - 06 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Mots-clés : Lubrication Magnetic fields Magnetohydrodynamics Viscosity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The pure squeeze magneto-elastohydrodynamic lubrication (MEHL) motion of circular contacts with an electrically conducting fluid in the presence of a transverse magnetic field is explored under constant load condition. The differences between classical elastohydrodynamic lubrication and MEHL are discussed. The results reveal that the effect of an externally applied magnetic field is equivalent to enhancing effective lubricant viscosity. Therefore, as the Hartmann number increases, the enhancing effect becomes more obvious. Furthermore, the transient pressure profiles, film shapes, normal squeeze velocities, and effective viscosity during the pure squeeze process under various operating conditions are discussed. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Titre : Research on the effect of whole cylinder block on EHL performance of main bearings considering crankshaft deformation for internal combustion engine Type de document : texte imprimé Auteurs : Jun Sun, Auteur ; Xiaoxia Cai, Auteur ; Liping Liu, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Elastic deformation Elastodynamics Heat engines Hydrodynamics Lubrication Machine bearings Shafts Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In this paper, the analyses of elastohydrodynamic lubrication (EHL) of crankshaft bearings considering the deformation of the whole cylinder block and crankshaft under load were carried out for the crankshaft bearing system of a four-stroke four-cylinder internal combustion engine. The lubrication of crankshaft bearing was analyzed by dynamic method. The deformation of bearing surface under pressure of oil film was calculated by compliance matrix method. The results show that when the crankshaft deformation under load is considered, compared with the results of not considering the deformation of cylinder block, the maximum film pressure decreases, the minimum film thickness increases, and the end leakage flow-rate and frictional coefficient of journal surface change little in an engine working cycle when considering the deformation of cylinder block. The models of the whole cylinder block and the single main bearing housing were used, respectively, to calculate the deformation of main bearing surface in the analyses. The results show that the calculation accuracy of the elastohydrodynamic lubrication analyses of crankshaft main bearings can be met basically by applying the simple model based on the single main bearing housing to calculate the elastic deformation of main bearing surface. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Research on the effect of whole cylinder block on EHL performance of main bearings considering crankshaft deformation for internal combustion engine [texte imprimé] / Jun Sun, Auteur ; Xiaoxia Cai, Auteur ; Liping Liu, Auteur . - 2011 . - 06 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Mots-clés : Elastic deformation Elastodynamics Heat engines Hydrodynamics Lubrication Machine bearings Shafts Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : In this paper, the analyses of elastohydrodynamic lubrication (EHL) of crankshaft bearings considering the deformation of the whole cylinder block and crankshaft under load were carried out for the crankshaft bearing system of a four-stroke four-cylinder internal combustion engine. The lubrication of crankshaft bearing was analyzed by dynamic method. The deformation of bearing surface under pressure of oil film was calculated by compliance matrix method. The results show that when the crankshaft deformation under load is considered, compared with the results of not considering the deformation of cylinder block, the maximum film pressure decreases, the minimum film thickness increases, and the end leakage flow-rate and frictional coefficient of journal surface change little in an engine working cycle when considering the deformation of cylinder block. The models of the whole cylinder block and the single main bearing housing were used, respectively, to calculate the deformation of main bearing surface in the analyses. The results show that the calculation accuracy of the elastohydrodynamic lubrication analyses of crankshaft main bearings can be met basically by applying the simple model based on the single main bearing housing to calculate the elastic deformation of main bearing surface. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 05 p.
Titre : Microstructure and wear properties of laser clad (Ti,Mo)C multiple carbide reinforced Fe-based composite coating Type de document : texte imprimé Auteurs : Xinhong Wang, Auteur ; Min Zhang, Auteur ; Shiyao Qu, Auteur Année de publication : 2011 Article en page(s) : 05 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Cladding techniques Claddings Cracks Crystallisation Dissolving Iron Laser materials processing Molybdenum compounds Nucleation Particle reinforced composites Particle size Titanium compounds Wear resistance Wear resistant coatings Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : (Ti,Mo)C multiple carbide reinforced Fe-based composite coating was produced by laser melting a precursor mixture graphite, ferrotitanium (Fe–Ti), and ferromolybdenum (Fe–Mo) powders. The results showed that flowerlike and cubic type (Ti,Mo)C multiple carbides were formed during laser cladding process. The selective area diffraction pattern analysis indicated that (Ti,Mo)C crystallizes with cubic structure, which indicates that (Ti,Mo)C carbides were multiple carbides with Mo dissolved in the TiC structure. The formation of (Ti,Mo)C particles was achieved via a nucleation-growth mechanism during the laser cladding process. Increasing the amount of Fe–Mo in the reactants led to a decrease of carbide size and an increase of volume fraction of carbides. The coating possessed good cracking resistance when the amount of Fe–Mo was controlled within a range of 15 wt %. The Fe-based surface coating reinforced by (Ti,Mo)C multiple carbides gave an excellent wear resistance. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Microstructure and wear properties of laser clad (Ti,Mo)C multiple carbide reinforced Fe-based composite coating [texte imprimé] / Xinhong Wang, Auteur ; Min Zhang, Auteur ; Shiyao Qu, Auteur . - 2011 . - 05 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 05 p.
Mots-clés : Cladding techniques Claddings Cracks Crystallisation Dissolving Iron Laser materials processing Molybdenum compounds Nucleation Particle reinforced composites Particle size Titanium compounds Wear resistance Wear resistant coatings Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : (Ti,Mo)C multiple carbide reinforced Fe-based composite coating was produced by laser melting a precursor mixture graphite, ferrotitanium (Fe–Ti), and ferromolybdenum (Fe–Mo) powders. The results showed that flowerlike and cubic type (Ti,Mo)C multiple carbides were formed during laser cladding process. The selective area diffraction pattern analysis indicated that (Ti,Mo)C crystallizes with cubic structure, which indicates that (Ti,Mo)C carbides were multiple carbides with Mo dissolved in the TiC structure. The formation of (Ti,Mo)C particles was achieved via a nucleation-growth mechanism during the laser cladding process. Increasing the amount of Fe–Mo in the reactants led to a decrease of carbide size and an increase of volume fraction of carbides. The coating possessed good cracking resistance when the amount of Fe–Mo was controlled within a range of 15 wt %. The Fe-based surface coating reinforced by (Ti,Mo)C multiple carbides gave an excellent wear resistance. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 05 p.
Titre : Repeatability estimation in galling resistance testing Type de document : texte imprimé Auteurs : Scott R. Hummel, Auteur ; Jeffrey Helm, Auteur Année de publication : 2011 Article en page(s) : 05 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Adhesion Plastic deformation Probability Stainless steel Welding Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Galling is a severe form of mechanical surface damage, commonly observed in metals, that is accompanied by adhesive transfer, extensive plastic deformation, and/or cold-welding of the mating surfaces. It can lead to seizure or rapid failure of machine components. Stainless steels are particularly prone to galling. A new galling test and analysis method that reflects the statistical nature of galling is described. The new ASTM method (G196), which embodies a probabilistic approach to galling, is superior to an older ASTM test method (G98), which produces only a single threshold stress for a given combination of materials. A computer-modeled experiment involving a 300 series stainless steel is used to illustrate how the enhanced analysis can be applied to determine the repeatability of galling test results. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Repeatability estimation in galling resistance testing [texte imprimé] / Scott R. Hummel, Auteur ; Jeffrey Helm, Auteur . - 2011 . - 05 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 05 p.
Mots-clés : Adhesion Plastic deformation Probability Stainless steel Welding Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Galling is a severe form of mechanical surface damage, commonly observed in metals, that is accompanied by adhesive transfer, extensive plastic deformation, and/or cold-welding of the mating surfaces. It can lead to seizure or rapid failure of machine components. Stainless steels are particularly prone to galling. A new galling test and analysis method that reflects the statistical nature of galling is described. The new ASTM method (G196), which embodies a probabilistic approach to galling, is superior to an older ASTM test method (G98), which produces only a single threshold stress for a given combination of materials. A computer-modeled experiment involving a 300 series stainless steel is used to illustrate how the enhanced analysis can be applied to determine the repeatability of galling test results. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Titre : Experimental studies using response surface methodology for condition monitoring of ball bearings Type de document : texte imprimé Auteurs : M. S. Patil, Auteur ; Jose Mathew, Auteur ; P. K. Rajendrakumar, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Condition monitoring Machine bearings Response surface methodology Vibrations Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The presence of defect in the bearing (outer race, inner race, or ball) results in increased vibrations. Time domain indices such as rms, crest factor, and kurtosis are some of the important parameters used to monitor the condition of the bearing. Radial load and operating speed also have an important role in bearing vibrations. The interaction between the defect size, load, and speed helps to study their effect on vibrations more effectively. Response surface methodology (RSM) is a combination of statistical and mathematical techniques to represent the relationship between the inputs and the outputs of a physical system. But so far, the literature related to its application in bearing damage identification is scarce. The proposed study uses RSM to study the influence of defect size, load, and speed on the bearing vibrations. Kurtosis is used as response factor. Experiments are planned using Box Behnken design procedure. Experiments are performed using 6305 ball bearings and the results have been presented. MINITAB statistical software is used for analysis. It is seen from the analysis of the experimental results that the defect size, interaction effect of defect size and load, and interaction effect of defect size and speed are significant. Response surface method using Box Behnken design and analysis of variance has proved to be a successful technique to assess the significant factors related to bearing vibrations. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Experimental studies using response surface methodology for condition monitoring of ball bearings [texte imprimé] / M. S. Patil, Auteur ; Jose Mathew, Auteur ; P. K. Rajendrakumar, Auteur . - 2011 . - 06 p.
Tribology
Langues : Anglais (eng)
in Transactions of the ASME . Journal of tribology > Vol. 132 N° 4 (Octobre 2010) . - 06 p.
Mots-clés : Condition monitoring Machine bearings Response surface methodology Vibrations Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The presence of defect in the bearing (outer race, inner race, or ball) results in increased vibrations. Time domain indices such as rms, crest factor, and kurtosis are some of the important parameters used to monitor the condition of the bearing. Radial load and operating speed also have an important role in bearing vibrations. The interaction between the defect size, load, and speed helps to study their effect on vibrations more effectively. Response surface methodology (RSM) is a combination of statistical and mathematical techniques to represent the relationship between the inputs and the outputs of a physical system. But so far, the literature related to its application in bearing damage identification is scarce. The proposed study uses RSM to study the influence of defect size, load, and speed on the bearing vibrations. Kurtosis is used as response factor. Experiments are planned using Box Behnken design procedure. Experiments are performed using 6305 ball bearings and the results have been presented. MINITAB statistical software is used for analysis. It is seen from the analysis of the experimental results that the defect size, interaction effect of defect size and load, and interaction effect of defect size and speed are significant. Response surface method using Box Behnken design and analysis of variance has proved to be a successful technique to assess the significant factors related to bearing vibrations. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]
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