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Experimental study of adhesive static friction in a spherical elastic-plastic contact / A. Ovcharenko in Transactions of the ASME . Journal of tribology, Vol. 130 n°2 (Mars/Avril 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 130 n°2 (Mars/Avril 2008) . - 6 p. Titre : Experimental study of adhesive static friction in a spherical elastic-plastic contact Type de document : texte imprimé Auteurs : A. Ovcharenko, Auteur ; G. Halperin, Auteur ; I. Etsion, Auteur Année de publication : 2008 Article en page(s) : 6 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Deformable  sphereAdhesive  static  friction Résumé : The elastic-plastic contact between a deformable sphere and a rigid flat during presliding is studied experimentally. Measurements of friction force and contact area are done in real time along with an accurate identification of the instant of sliding inception. The static friction force and relative tangential displacement are investigated over a wide range of normal preloads for several sphere materials and diameters. Different behavior of the static friction is observed in the elastic and in the elastic-plastic regimes of sphere deformation. It is found that at low normal loads, the static friction coefficient depends on the normal load in breach of the classical laws of friction. The presliding displacement is found to be less than 5% of the contact diameter, and the interface mean shear stress at sliding inception is found to be slightly below the shear strength of the sphere material. Good correlation is found between the present experimental results and a recent theoretical model in the elastic-plastic regime of deformation. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleID=1468006 [article] Experimental study of adhesive static friction in a spherical elastic-plastic contact [texte imprimé] / A. Ovcharenko, Auteur ; G. Halperin, Auteur ; I. Etsion, Auteur . - 2008 . - 6 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 130 n°2 (Mars/Avril 2008) . - 6 p. Mots-clés : Deformable  sphereAdhesive  static  friction Résumé : The elastic-plastic contact between a deformable sphere and a rigid flat during presliding is studied experimentally. Measurements of friction force and contact area are done in real time along with an accurate identification of the instant of sliding inception. The static friction force and relative tangential displacement are investigated over a wide range of normal preloads for several sphere materials and diameters. Different behavior of the static friction is observed in the elastic and in the elastic-plastic regimes of sphere deformation. It is found that at low normal loads, the static friction coefficient depends on the normal load in breach of the classical laws of friction. The presliding displacement is found to be less than 5% of the contact diameter, and the interface mean shear stress at sliding inception is found to be slightly below the shear strength of the sphere material. Good correlation is found between the present experimental results and a recent theoretical model in the elastic-plastic regime of deformation. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleID=1468006

Transient thermomechanical contact of an impacting sphere on a moving flat / A. Ovcharenko in Transactions of the ASME . Journal of tribology, Vol. 133 N° 3 (Juillet 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 133 N° 3 (Juillet 2011) . - 09 p. Titre : Transient thermomechanical contact of an impacting sphere on a moving flat Type de document : texte imprimé Auteurs : A. Ovcharenko, Auteur ; M. Yang, Auteur ; K. Chun, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Discs  (structures)  Elastic  deformation  Friction  Hardening  Mechanical  contact  Plastic  deformation  Thermomechanical  treatment  Velocity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Contact between a slider and a magnetic recording disk is modeled as transient contact of a sphere on a moving flat. The sphere is assumed to be rigid, and the flat is treated as an elastic-plastic body with isotropic hardening. Heat generation is related to friction at the contact interface. Dimensionless solutions are obtained for maximum temperature rise, maximum contact force, maximum contact area, and maximum penetration as a function of dimensionless vertical initial velocity of the sphere. It is observed that transient thermomechanical contact with elastic-plastic deformation deviates from “classical theories” for dynamic elastic and quasi-static elastic-plastic contacts as the dimensionless vertical initial velocity of the sphere increases. The results are applied to optimize the slider-disk interface in a hard disk drive with respect to slider-disk contacts. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Transient thermomechanical contact of an impacting sphere on a moving flat [texte imprimé] / A. Ovcharenko, Auteur ; M. Yang, Auteur ; K. Chun, Auteur . - 2012 . - 09 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 133 N° 3 (Juillet 2011) . - 09 p. Mots-clés : Discs  (structures)  Elastic  deformation  Friction  Hardening  Mechanical  contact  Plastic  deformation  Thermomechanical  treatment  Velocity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Contact between a slider and a magnetic recording disk is modeled as transient contact of a sphere on a moving flat. The sphere is assumed to be rigid, and the flat is treated as an elastic-plastic body with isotropic hardening. Heat generation is related to friction at the contact interface. Dimensionless solutions are obtained for maximum temperature rise, maximum contact force, maximum contact area, and maximum penetration as a function of dimensionless vertical initial velocity of the sphere. It is observed that transient thermomechanical contact with elastic-plastic deformation deviates from “classical theories” for dynamic elastic and quasi-static elastic-plastic contacts as the dimensionless vertical initial velocity of the sphere increases. The results are applied to optimize the slider-disk interface in a hard disk drive with respect to slider-disk contacts. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]