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Investigation of contact stiffness and contact damping for magnetic storage head-disk interfaces / Xi Shi 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) . - 9 p. Titre : Investigation of contact stiffness and contact damping for magnetic storage head-disk interfaces Type de document : texte imprimé Auteurs : Xi Shi, Auteur ; Andreas A. Polycarpou, Auteur Année de publication : 2008 Article en page(s) : 9 p. Note générale : Tribology Langues : Anglais (eng) Résumé : As the areal density of magnetic disk storage continues to increase and head-disk spacing decreases, contact between the recording slider and the rotating media becomes imminent. In order to predict contact forces, fly-height modulations, and off-track motions, dynamic models are typically used. A critical element of these models is the contact stiffness and damping arising from the interfacial interaction between the slider and the disk. In this paper, we review different models for predicting contact stiffness based on roughness and layered media and then we report experimental data of both contact stiffness and contact damping of typical head-disk interfaces. It is found that the contact stiffness models (based on roughness alone) overpredict the contact stiffness of actual head-disk interfaces by as much as an order of magnitude. Also, it is found that the contact damping ratio is typically few percent and its behavior is substrate dependent. In addition, the effects of a molecularly thin lubricant and humidity on contact stiffness and damping were experimentally investigated and no significant effects were found. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468038 [article] Investigation of contact stiffness and contact damping for magnetic storage head-disk interfaces [texte imprimé] / Xi Shi, Auteur ; Andreas A. Polycarpou, Auteur . - 2008 . - 9 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 130 n°2 (Mars/Avril 2008) . - 9 p. Résumé : As the areal density of magnetic disk storage continues to increase and head-disk spacing decreases, contact between the recording slider and the rotating media becomes imminent. In order to predict contact forces, fly-height modulations, and off-track motions, dynamic models are typically used. A critical element of these models is the contact stiffness and damping arising from the interfacial interaction between the slider and the disk. In this paper, we review different models for predicting contact stiffness based on roughness and layered media and then we report experimental data of both contact stiffness and contact damping of typical head-disk interfaces. It is found that the contact stiffness models (based on roughness alone) overpredict the contact stiffness of actual head-disk interfaces by as much as an order of magnitude. Also, it is found that the contact damping ratio is typically few percent and its behavior is substrate dependent. In addition, the effects of a molecularly thin lubricant and humidity on contact stiffness and damping were experimentally investigated and no significant effects were found. En ligne : http://tribology.asmedigitalcollection.asme.org/article.aspx?articleid=1468038

Investigation of inclined planar rough surfaces contact from static to sliding / Ting Ni in Transactions of the ASME . Journal of tribology, Vol. 132 N° 4 (Octobre 2010) 

Public ISBD [article]  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 [...]