Documents disponibles écrits par cet auteur

Analytical solution to the hydrodynamic lubrication of fan-shaped thrust step bearings / Shuangbiao Liu in Transactions of the ASME . Journal of tribology, Vol. 132 N° 2 (Avril 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 132 N° 2 (Avril 2010) . - 08 p. Titre : Analytical solution to the hydrodynamic lubrication of fan-shaped thrust step bearings Type de document : texte imprimé Auteurs : Shuangbiao Liu, Auteur ; W. Wayne Chen, Auteur ; Diann Y. Hua, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Hydrodynamics  Laplace  equations  Lubrication  Machine  bearings Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Step bearings are frequently used in industries for better load capacities. Analytical solutions to the Rayleigh step bearing and a rectangular slider with a finite width are available in literature, but none for a fan-shaped thrust step bearing. This study starts with a known solution to the Laplace equation in a cylindrical coordinate system, which is in the form of an infinite summation. A set of analytical solutions to pressure, load capacity, flow rate, and torque loss is derived in this paper for hydrodynamic lubrication problems encountered in the fan-shaped step bearing. These analytical solutions are compared with those for the rectangular slider and the Rayleigh step bearing to reveal relationships among them. When the inner radius becomes smaller, the load capacity increases, almost linearly in a certain region. The effects of inner radius, step height, and step location on pressure distribution and load capacity are studied in general and under a specific set of bearing geometry as an example. The presented solutions can be useful for designers to maximize bearing performance as well as for researchers to benchmark numerical lubrication models. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Analytical solution to the hydrodynamic lubrication of fan-shaped thrust step bearings [texte imprimé] / Shuangbiao Liu, Auteur ; W. Wayne Chen, Auteur ; Diann Y. Hua, Auteur . - 2011 . - 08 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 132 N° 2 (Avril 2010) . - 08 p. Mots-clés : Hydrodynamics  Laplace  equations  Lubrication  Machine  bearings Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Step bearings are frequently used in industries for better load capacities. Analytical solutions to the Rayleigh step bearing and a rectangular slider with a finite width are available in literature, but none for a fan-shaped thrust step bearing. This study starts with a known solution to the Laplace equation in a cylindrical coordinate system, which is in the form of an infinite summation. A set of analytical solutions to pressure, load capacity, flow rate, and torque loss is derived in this paper for hydrodynamic lubrication problems encountered in the fan-shaped step bearing. These analytical solutions are compared with those for the rectangular slider and the Rayleigh step bearing to reveal relationships among them. When the inner radius becomes smaller, the load capacity increases, almost linearly in a certain region. The effects of inner radius, step height, and step location on pressure distribution and load capacity are studied in general and under a specific set of bearing geometry as an example. The presented solutions can be useful for designers to maximize bearing performance as well as for researchers to benchmark numerical lubrication models. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]

Semi-analytical viscoelastic contact modeling of polymer-based materials / W. Wayne Chen in Transactions of the ASME . Journal of tribology, Vol. 133 N° 4 (Octobre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 133 N° 4 (Octobre 2011) . - 10 p. Titre : Semi-analytical viscoelastic contact modeling of polymer-based materials Type de document : texte imprimé Auteurs : W. Wayne Chen, Auteur ; Q. Jane Wang, Auteur ; Z. Huan, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Triboblogy Langues : Anglais (eng) Mots-clés : Conjugate  gradient  methods  Fast  Fourier  transforms  Indentation  Mechanical  contact  Polymers  Surface  roughness  Time-domain  analysis  Transient  analysis  Viscoelasticity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Contact of viscoelastic materials with complicated properties and surface topography require numerical solution approaches. This paper presents a 3-D semianalytical contact model for viscoelastic materials. With the hereditary integral operator and elastic-viscoelastic correspondence principle, surface displacement is expressed in terms of viscoelastic creep compliance and contact pressure distribution history in the course of a contact process. Through discretizing the contact equations in both spatial and temporal dimensions, a numerical algorithm based on the robust Conjugate Gradient method and Fast Fourier transform has been developed to solve the normal approach, contact pressure, and real contact area simultaneously. The transient contact analysis in the time domain is computationally expensive. The fast Fourier transform algorithm can help reduce the computation cost significantly. The comparisons of the new numerical results with an analytical viscoelastic contact solution for Maxwell materials and with an indentation test measurement reported in the literature has validated and demonstrated the accuracy of the proposed model. Moreover, the present model has been used to simulate the contact between a polymethyl methacrylate (PMMA) substrate and a rigid sphere driven by step, ramped, and harmonic normal loads. The validated model and numerical method can successfully compute the viscoelastic contact responses of polymer-based materials with time-dependent properties and surface roughness subjected to complicated loading profiles. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Semi-analytical viscoelastic contact modeling of polymer-based materials [texte imprimé] / W. Wayne Chen, Auteur ; Q. Jane Wang, Auteur ; Z. Huan, Auteur . - 2012 . - 10 p. Triboblogy Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 133 N° 4 (Octobre 2011) . - 10 p. Mots-clés : Conjugate  gradient  methods  Fast  Fourier  transforms  Indentation  Mechanical  contact  Polymers  Surface  roughness  Time-domain  analysis  Transient  analysis  Viscoelasticity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Contact of viscoelastic materials with complicated properties and surface topography require numerical solution approaches. This paper presents a 3-D semianalytical contact model for viscoelastic materials. With the hereditary integral operator and elastic-viscoelastic correspondence principle, surface displacement is expressed in terms of viscoelastic creep compliance and contact pressure distribution history in the course of a contact process. Through discretizing the contact equations in both spatial and temporal dimensions, a numerical algorithm based on the robust Conjugate Gradient method and Fast Fourier transform has been developed to solve the normal approach, contact pressure, and real contact area simultaneously. The transient contact analysis in the time domain is computationally expensive. The fast Fourier transform algorithm can help reduce the computation cost significantly. The comparisons of the new numerical results with an analytical viscoelastic contact solution for Maxwell materials and with an indentation test measurement reported in the literature has validated and demonstrated the accuracy of the proposed model. Moreover, the present model has been used to simulate the contact between a polymethyl methacrylate (PMMA) substrate and a rigid sphere driven by step, ramped, and harmonic normal loads. The validated model and numerical method can successfully compute the viscoelastic contact responses of polymer-based materials with time-dependent properties and surface roughness subjected to complicated loading profiles. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]

Thermomechanical analysis of elastoplastic bodies in a sliding spherical contact and the effects of sliding speed, heat partition, and thermal softening / W. Wayne Chen in Transactions of the ASME . Journal of tribology, Vol. 130 N° 4 (Octobre 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 130 N° 4 (Octobre 2008) . - 10 p. Titre : Thermomechanical analysis of elastoplastic bodies in a sliding spherical contact and the effects of sliding speed, heat partition, and thermal softening Type de document : texte imprimé Auteurs : W. Wayne Chen, Auteur ; Q. Jane Wang, Auteur Article en page(s) : 10 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Friction  Heat  Temperature  Stress  Interior  walls  Pressure  Elastic  half  space  Heating  Heat  flux  Deformation Résumé : A thermomechanical analysis of elasto-plastic bodies is a necessary step toward the understanding of tribological behaviors of machine components subjected to both mechanical loading and frictional heating. A three-dimensional thermoelastoplastic contact model for counterformal bodies has been developed, which takes into account steady state heat flux, temperature-dependent strain hardening behavior, and interaction of mechanical and thermal loads. The fast Fourier transform and conjugate gradient method are the underlying numerical algorithms used in this model. Sliding of a half-space over a stationary sphere is simulated with this model. The friction-induced heat is partitioned into two bodies based on surface temperature distributions. In the simulation, the sphere is considered to be fully thermoelastoplastic, while the half-space is treated to be thermoelastic. Simulation results include surface pressure, temperature rise, and subsurface stress and plastic strain fields. The paper also studies the influences of sliding speed and thermal softening on contact behaviors for sliding speed ranging three orders of magnitude. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleID=1468101 [article] Thermomechanical analysis of elastoplastic bodies in a sliding spherical contact and the effects of sliding speed, heat partition, and thermal softening [texte imprimé] / W. Wayne Chen, Auteur ; Q. Jane Wang, Auteur . - 10 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 130 N° 4 (Octobre 2008) . - 10 p. Mots-clés : Friction  Heat  Temperature  Stress  Interior  walls  Pressure  Elastic  half  space  Heating  Heat  flux  Deformation Résumé : A thermomechanical analysis of elasto-plastic bodies is a necessary step toward the understanding of tribological behaviors of machine components subjected to both mechanical loading and frictional heating. A three-dimensional thermoelastoplastic contact model for counterformal bodies has been developed, which takes into account steady state heat flux, temperature-dependent strain hardening behavior, and interaction of mechanical and thermal loads. The fast Fourier transform and conjugate gradient method are the underlying numerical algorithms used in this model. Sliding of a half-space over a stationary sphere is simulated with this model. The friction-induced heat is partitioned into two bodies based on surface temperature distributions. In the simulation, the sphere is considered to be fully thermoelastoplastic, while the half-space is treated to be thermoelastic. Simulation results include surface pressure, temperature rise, and subsurface stress and plastic strain fields. The paper also studies the influences of sliding speed and thermal softening on contact behaviors for sliding speed ranging three orders of magnitude. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleID=1468101