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Dual time stepping algorithms with the high order harmonic balance method for contact interfaces with fretting-wear / Loïc Salles in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 3 (Mars 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 3 (Mars 2012) . - 07 p. Titre : Dual time stepping algorithms with the high order harmonic balance method for contact interfaces with fretting-wear Type de document : texte imprimé Auteurs : Loïc Salles, Auteur ; Laurent Blanc, Auteur ; Fabrice Thouverez, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Computational  fluid  dynamics  Damping  Frequency-domain  analysis  Friction  Turbomachinery  Vibrations  Wear Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Contact interfaces with dry friction are frequently used in turbomachinery. Dry friction damping produced by the sliding surfaces of these interfaces reduces the amplitude of bladed-disk vibration. The relative displacements at these interfaces lead to fretting-wear which reduces the average life expectancy of the structure. Frequency response functions are calculated numerically by using the multi-harmonic balance method (mHBM). The dynamic Lagrangian frequency-time method is used to calculate contact forces in the frequency domain. A new strategy for solving nonlinear systems based on dual time stepping is applied. This method is faster than using Newton solvers. It was used successfully for solving Nonlinear CFD equations in the frequency domain. This new approach allows identifying the steady state of worn systems by integrating wear rate equations a on dual time scale. The dual time equations are integrated by an implicit scheme. Of the different orders tested, the first order scheme provided the best results. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000003 [...] [article] Dual time stepping algorithms with the high order harmonic balance method for contact interfaces with fretting-wear [texte imprimé] / Loïc Salles, Auteur ; Laurent Blanc, Auteur ; Fabrice Thouverez, Auteur . - 2012 . - 07 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 3 (Mars 2012) . - 07 p. Mots-clés : Computational  fluid  dynamics  Damping  Frequency-domain  analysis  Friction  Turbomachinery  Vibrations  Wear Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Contact interfaces with dry friction are frequently used in turbomachinery. Dry friction damping produced by the sliding surfaces of these interfaces reduces the amplitude of bladed-disk vibration. The relative displacements at these interfaces lead to fretting-wear which reduces the average life expectancy of the structure. Frequency response functions are calculated numerically by using the multi-harmonic balance method (mHBM). The dynamic Lagrangian frequency-time method is used to calculate contact forces in the frequency domain. A new strategy for solving nonlinear systems based on dual time stepping is applied. This method is faster than using Newton solvers. It was used successfully for solving Nonlinear CFD equations in the frequency domain. This new approach allows identifying the steady state of worn systems by integrating wear rate equations a on dual time scale. The dual time equations are integrated by an implicit scheme. Of the different orders tested, the first order scheme provided the best results. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000003 [...]

Dynamic analysis of fretting-wear in friction contact interfaces / Loïc Salles in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 1 (Janvier 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 1 (Janvier 2010) . - 09 p. Titre : Dynamic analysis of fretting-wear in friction contact interfaces Type de document : texte imprimé Auteurs : Loïc Salles, Auteur ; Laurent Blanc, Auteur ; Fabrice Thouverez, Auteur Année de publication : 2010 Article en page(s) : 09 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Friction  Mechanical  contact  Turbomachinery  Wear Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Fretting wear is a very important phenomenon occurring in bladed disks. It causes the blades to be replaced in turbomachines during their life-cycle. Methods exist to predict fretting-wear in quasistatic analysis. However, they do not predict all the phenomena observed in blade attachments on real turbomachines. That is why this study assumes that dynamics plays a role in fretting-wear. This paper is devoted to the realistic modeling and calculation of fretting-wear and dynamical response of structures in unilateral contact with friction. Vibration and wear phenomena present very different scales both in time and space. Therefore the difficulty is in finding methods that enable one to solve the nonlinear problem with a good compromise between the approximations made about the dynamical aspects and those linked with fretting-wear issues. Here, phenomenological examples are studied. They involve a small number of degrees of freedom with a view to understanding the complex coupling between vibration and fretting-wear. This way, they will show the relative importance of parameters. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000001 [...] [article] Dynamic analysis of fretting-wear in friction contact interfaces [texte imprimé] / Loïc Salles, Auteur ; Laurent Blanc, Auteur ; Fabrice Thouverez, Auteur . - 2010 . - 09 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 1 (Janvier 2010) . - 09 p. Mots-clés : Friction  Mechanical  contact  Turbomachinery  Wear Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Fretting wear is a very important phenomenon occurring in bladed disks. It causes the blades to be replaced in turbomachines during their life-cycle. Methods exist to predict fretting-wear in quasistatic analysis. However, they do not predict all the phenomena observed in blade attachments on real turbomachines. That is why this study assumes that dynamics plays a role in fretting-wear. This paper is devoted to the realistic modeling and calculation of fretting-wear and dynamical response of structures in unilateral contact with friction. Vibration and wear phenomena present very different scales both in time and space. Therefore the difficulty is in finding methods that enable one to solve the nonlinear problem with a good compromise between the approximations made about the dynamical aspects and those linked with fretting-wear issues. Here, phenomenological examples are studied. They involve a small number of degrees of freedom with a view to understanding the complex coupling between vibration and fretting-wear. This way, they will show the relative importance of parameters. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000001 [...]