Documents disponibles écrits par cet auteur

A new approach for rolling contact fatigue numerical study / Arthur Francisco 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) . - 12 p. Titre : A new approach for rolling contact fatigue numerical study : application to a brittle epoxy resin Type de document : texte imprimé Auteurs : Arthur Francisco, Auteur ; Houssein Abbouchi, Auteur ; Bernard Villechaise, Auteur Année de publication : 2012 Article en page(s) : 12 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Brittleness  Design  of  experiments  Discs  (structures)  Fatigue  cracks  Finite  element  analysis  Mechanical  contact  Polymers  Resins  Rolling  friction  Stick-slip Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The background of the present study is the rolling contact fatigue (RCF) in a brittle polymer disk. The disk has been tested on a two disk machine, under controlled normal and tangential loads, with no global slip. After several million cycles and under different operating conditions, it has been observed that (1) the tangential load highly influences the RCF phenomenon, (2) a network of regularly spaced cracks appears, and (3) in the driving position, the RCF phenomenon develops faster. To explain these observations, a numerical model based on the finite element method (FEM) has been built: the cracks have been quite simply modeled, stick-slip has been chosen as the friction model, and the disk-on-disk contact has been replaced by a disk-on-plane contact. To study the influence of some of the operating conditions, the design of experiments (DOE) techniques has been used. The statistical postprocessing associated to DOE has confirmed the experimental observations with a good reliability. In addition, with some mechanical considerations, scenarios of what experimentally happens are proposed. The association FEM/DOE is an original and efficient way to explain phenomena in the field of RCF: the accuracy of the FEM coupled with DOE statistical treatments make it possible to have a good predictability despite some uncontrolled parameters. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] A new approach for rolling contact fatigue numerical study : application to a brittle epoxy resin [texte imprimé] / Arthur Francisco, Auteur ; Houssein Abbouchi, Auteur ; Bernard Villechaise, Auteur . - 2012 . - 12 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 133 N° 3 (Juillet 2011) . - 12 p. Mots-clés : Brittleness  Design  of  experiments  Discs  (structures)  Fatigue  cracks  Finite  element  analysis  Mechanical  contact  Polymers  Resins  Rolling  friction  Stick-slip Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : The background of the present study is the rolling contact fatigue (RCF) in a brittle polymer disk. The disk has been tested on a two disk machine, under controlled normal and tangential loads, with no global slip. After several million cycles and under different operating conditions, it has been observed that (1) the tangential load highly influences the RCF phenomenon, (2) a network of regularly spaced cracks appears, and (3) in the driving position, the RCF phenomenon develops faster. To explain these observations, a numerical model based on the finite element method (FEM) has been built: the cracks have been quite simply modeled, stick-slip has been chosen as the friction model, and the disk-on-disk contact has been replaced by a disk-on-plane contact. To study the influence of some of the operating conditions, the design of experiments (DOE) techniques has been used. The statistical postprocessing associated to DOE has confirmed the experimental observations with a good reliability. In addition, with some mechanical considerations, scenarios of what experimentally happens are proposed. The association FEM/DOE is an original and efficient way to explain phenomena in the field of RCF: the accuracy of the FEM coupled with DOE statistical treatments make it possible to have a good predictability despite some uncontrolled parameters. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]

Study of a brittle transparent disk under dry RCF conditions / Arthur Francisco in Transactions of the ASME . Journal of tribology, Vol. 132 N° 3 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 132 N° 3 (Juillet 2010) . - 08 p. Titre : Study of a brittle transparent disk under dry RCF conditions Type de document : texte imprimé Auteurs : Arthur Francisco, Auteur ; Houssein Abbouchi, Auteur ; Bernard Villechaise, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Tribology Langues : Anglais (eng) Mots-clés : Brittleness  Discs  (structures)  Fatigue  Mechanical  contact  Rolling  friction  Tensile  strength Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Despite the numerous experimental works on rolling contact fatigue, dealing with two-disk contacts, some phenomena still remain badly understood. Most of the test benches, used for that purpose, impose the rotational speeds to the disks: global slipping occurs and the tangential force is measured. Even if this configuration is found in some mechanical contacts, it does not reflect situations, where only microslipping occurs with high tangential loads. For these reasons, an original bench has been designed: a specimen disk rotates a braked stainless steel disk under a normal load N. The tangential load T, due to the braked disk, is set below the global slipping value; the specimen disks are transparent for the cracks observation and brittle to avoid any plasticity complication. A typical run consists in carrying out a succession of steps of increasing the number of cycles. Each step ends with several measurements on the cracks: their counting and their width and depth measurements. The results are divided in two categories: general observations and quantitative results. The most evident observation concerns the crack shape since it propagates along an ellipse on the contact path. Furthermore, the direction of propagation inside the disk is perpendicular to the surface. Lastly, a regular primary network of well-defined cracks is observed with cracks less marked. Concerning the effects of varying loads, the higher the T, the faster the cracks initiate and propagate because of a higher tensile stress state. However, these effects can be partly overridden by N beneath the contact path. As the disk material is brittle, the crack behavior is quite similar to the one observed on metallic specimens. Even if the results are obtained in an epoxy resin, a reasonable transposition is possible. The disk transparency makes it possible to quantify the cracks growth and to propose original 3D photographs of the cracks. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...] [article] Study of a brittle transparent disk under dry RCF conditions [texte imprimé] / Arthur Francisco, Auteur ; Houssein Abbouchi, Auteur ; Bernard Villechaise, Auteur . - 2011 . - 08 p. Tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 132 N° 3 (Juillet 2010) . - 08 p. Mots-clés : Brittleness  Discs  (structures)  Fatigue  Mechanical  contact  Rolling  friction  Tensile  strength Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Despite the numerous experimental works on rolling contact fatigue, dealing with two-disk contacts, some phenomena still remain badly understood. Most of the test benches, used for that purpose, impose the rotational speeds to the disks: global slipping occurs and the tangential force is measured. Even if this configuration is found in some mechanical contacts, it does not reflect situations, where only microslipping occurs with high tangential loads. For these reasons, an original bench has been designed: a specimen disk rotates a braked stainless steel disk under a normal load N. The tangential load T, due to the braked disk, is set below the global slipping value; the specimen disks are transparent for the cracks observation and brittle to avoid any plasticity complication. A typical run consists in carrying out a succession of steps of increasing the number of cycles. Each step ends with several measurements on the cracks: their counting and their width and depth measurements. The results are divided in two categories: general observations and quantitative results. The most evident observation concerns the crack shape since it propagates along an ellipse on the contact path. Furthermore, the direction of propagation inside the disk is perpendicular to the surface. Lastly, a regular primary network of well-defined cracks is observed with cracks less marked. Concerning the effects of varying loads, the higher the T, the faster the cracks initiate and propagate because of a higher tensile stress state. However, these effects can be partly overridden by N beneath the contact path. As the disk material is brittle, the crack behavior is quite similar to the one observed on metallic specimens. Even if the results are obtained in an epoxy resin, a reasonable transposition is possible. The disk transparency makes it possible to quantify the cracks growth and to propose original 3D photographs of the cracks. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE900013 [...]