https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Mon, 13 Jul 2026 06:05:27 GMT 2026-07-13T06:05:27Z http://hdl.handle.net/10985/8480 Numerical simulation and experimental study of thrust air bearings with multiple orifices CHARKI, Abdérafi; DIOP, Khadim; CHAMPMARTIN, Stephane; AMBARI, Abdelhak The objective of this paper is to provide a numerical simulation and an experimental study in order to assess stiffness and damping characteristics of thrust air bearings with multiple orifices. Finite element modeling is used to solve the non-linear Reynolds equation while taking into account the movement equation for the bearing. The numerical results obtained show that performance characteristics are related to bearing design type. An experimental investigation allows us to analyze the behavior of thrust air bearings with several orifices as well as that of groove or porous material bearings. Frequency response measurements have been realized in order to compare the dynamic properties of the different bearings. The frequency responses obtained demonstrate that air bearings with multiple orifices have a damping higher than the other types in certain conditions. Air bearings with multiple orifices offer many advantages from a dynamic point of view. Their performance may be characterized not only by flow conditions but also by the number or diameter of the orifices in the bearing surface. http://dx.doi.org/10.1016/j.ijmecsci.2013.03.006 Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/8480 2013-01-01T00:00:00Z CHARKI, Abdérafi DIOP, Khadim CHAMPMARTIN, Stephane AMBARI, Abdelhak The objective of this paper is to provide a numerical simulation and an experimental study in order to assess stiffness and damping characteristics of thrust air bearings with multiple orifices. Finite element modeling is used to solve the non-linear Reynolds equation while taking into account the movement equation for the bearing. The numerical results obtained show that performance characteristics are related to bearing design type. An experimental investigation allows us to analyze the behavior of thrust air bearings with several orifices as well as that of groove or porous material bearings. Frequency response measurements have been realized in order to compare the dynamic properties of the different bearings. The frequency responses obtained demonstrate that air bearings with multiple orifices have a damping higher than the other types in certain conditions. Air bearings with multiple orifices offer many advantages from a dynamic point of view. Their performance may be characterized not only by flow conditions but also by the number or diameter of the orifices in the bearing surface. http://hdl.handle.net/10985/10261 Reliability for fluid bearings design DIOP, Khadim; CHARKI, Abdérafi; CHAMPMARTIN, Stephane; AMBARI, Abdelhak This paper presents a new methodology for evaluating the failure probability of fluid bearings which are sensitive components for the design of machine rotors, mechatronic systems and high precision metrology. The static and dynamic behavior of a fluid bearing depends on several parameters, such as external load, bearing dimensions, supply pressure, quality of the machined surfaces, fluid properties, etc. In this paper, the characteristics of a simple geometry thrust bearing are calculated analytically in order demonstrate the usefulness of the proposal methodology and its pertinence to bearing design. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/10261 2013-01-01T00:00:00Z DIOP, Khadim CHARKI, Abdérafi CHAMPMARTIN, Stephane AMBARI, Abdelhak This paper presents a new methodology for evaluating the failure probability of fluid bearings which are sensitive components for the design of machine rotors, mechatronic systems and high precision metrology. The static and dynamic behavior of a fluid bearing depends on several parameters, such as external load, bearing dimensions, supply pressure, quality of the machined surfaces, fluid properties, etc. In this paper, the characteristics of a simple geometry thrust bearing are calculated analytically in order demonstrate the usefulness of the proposal methodology and its pertinence to bearing design. http://hdl.handle.net/10985/10250 Failure probability evaluation of a hydrodynamic journal bearing DIOP, Khadim; CHARKI, Abdérafi; CHAMPMARTIN, Stephane; AMBARI, Abdelhak Journal fluid bearings are widely used in industry due to their static and dynamic behavior and their very low coefficient of friction. The technical requirements to improve the new technologies design are increasingly focused on the indicators of dependability of systems and machines. Then, it is necessary to develop a methodology to study the reliability of bearings in order to improve and to evaluate their design quality. Few works are referenced in literature concerning the estimation of the reliability of journal fluid bearings. This paper deals with a methodology to study the failure probability of a hydrodynamic journal bearing. An analytical approach is proposed to calculate static characteristics in using the Reynolds equation. The commonly methods used in structural reliability such as FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and Monte Carlo are developed to estimate the failure probability. The function of performance bounding two domains (domain of safety and domain of failure) is estimated for several geometrical configurations of a hydrodynamic journal bearing (long journal bearings with the hypotheses of Sommerfeld, Gumbel and Reynolds, and a short journal bearing with the hypothesis of Gumbel). Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/10250 2015-01-01T00:00:00Z DIOP, Khadim CHARKI, Abdérafi CHAMPMARTIN, Stephane AMBARI, Abdelhak Journal fluid bearings are widely used in industry due to their static and dynamic behavior and their very low coefficient of friction. The technical requirements to improve the new technologies design are increasingly focused on the indicators of dependability of systems and machines. Then, it is necessary to develop a methodology to study the reliability of bearings in order to improve and to evaluate their design quality. Few works are referenced in literature concerning the estimation of the reliability of journal fluid bearings. This paper deals with a methodology to study the failure probability of a hydrodynamic journal bearing. An analytical approach is proposed to calculate static characteristics in using the Reynolds equation. The commonly methods used in structural reliability such as FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and Monte Carlo are developed to estimate the failure probability. The function of performance bounding two domains (domain of safety and domain of failure) is estimated for several geometrical configurations of a hydrodynamic journal bearing (long journal bearings with the hypotheses of Sommerfeld, Gumbel and Reynolds, and a short journal bearing with the hypothesis of Gumbel). http://hdl.handle.net/10985/10285 Reliability of a Hydrodynamic Journal Bearing DIOP, Khadim; CHARKI, Abdérafi; CHAMPMARTIN, Stephane; AMBARI, Abdelhak Journal fluid bearings are widely used in industry due to their static and dynamic behavior and their very low coefficient of friction. The technical requirements to improve the new technologies design are increasingly focused on the indicators of dependability of systems and machines. Then, it is necessary to develop a methodology to study the reliability of bearings in order to improve and to evaluate their design quality. Few works are referenced in literature concerning the estimation of the reliability of fluid journal bearings. This paper deals with a methodology to study the failure probability of a hydrodynamic journal bearing. An analytical approach is proposed to calculate static characteristics in using the Reynolds equation. The commonly methods used in structural reliability such as FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and Monte Carlo are developed to estimate the failure probability. The function of performance bounding two domains (domain of safety and domain of failure) is estimated for several geometrical configurations of a hydrodynamic journal bearing (long journal bearings with the hypotheses of Sommerfeld, Gümbel and Reynolds, and a short journal bearing with the hypothesis of Gümbel). Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/10285 2015-01-01T00:00:00Z DIOP, Khadim CHARKI, Abdérafi CHAMPMARTIN, Stephane AMBARI, Abdelhak Journal fluid bearings are widely used in industry due to their static and dynamic behavior and their very low coefficient of friction. The technical requirements to improve the new technologies design are increasingly focused on the indicators of dependability of systems and machines. Then, it is necessary to develop a methodology to study the reliability of bearings in order to improve and to evaluate their design quality. Few works are referenced in literature concerning the estimation of the reliability of fluid journal bearings. This paper deals with a methodology to study the failure probability of a hydrodynamic journal bearing. An analytical approach is proposed to calculate static characteristics in using the Reynolds equation. The commonly methods used in structural reliability such as FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and Monte Carlo are developed to estimate the failure probability. The function of performance bounding two domains (domain of safety and domain of failure) is estimated for several geometrical configurations of a hydrodynamic journal bearing (long journal bearings with the hypotheses of Sommerfeld, Gümbel and Reynolds, and a short journal bearing with the hypothesis of Gümbel). http://hdl.handle.net/10985/10283 Reliability of a Hydrodynamic Journal Bearing DIOP, Khadim; CHARKI, Abdérafi; CHAMPMARTIN, Stephane; AMBARI, Abdelhak Journal fluid bearings are widely used in industry due to their static and dynamic behavior and their very low coefficient of friction. The technical requirements to improve the new technologies design are increasingly focused on the indicators of dependability of systems and machines. Then, it is necessary to develop a methodology to study the reliability of bearings in order to improve and to evaluate their design quality. Few works are referenced in literature concerning the estimation of the reliability of fluid journal bearings. This paper deals with a methodology to study the failure probability of a hydrodynamic journal bearing. An analytical approach is proposed to calculate static characteristics in using the Reynolds equation. The commonly methods used in structural reliability such as FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and Monte Carlo are developed to estimate the failure probability. The function of performance bounding two domains (domain of safety and domain of failure) is estimated for several geometrical configurations of a hydrodynamic journal bearing (long journal bearings with the hypotheses of Sommerfeld, Gümbel and Reynolds, and a short journal bearing with the hypothesis of Gümbel). Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/10283 2015-01-01T00:00:00Z DIOP, Khadim CHARKI, Abdérafi CHAMPMARTIN, Stephane AMBARI, Abdelhak Journal fluid bearings are widely used in industry due to their static and dynamic behavior and their very low coefficient of friction. The technical requirements to improve the new technologies design are increasingly focused on the indicators of dependability of systems and machines. Then, it is necessary to develop a methodology to study the reliability of bearings in order to improve and to evaluate their design quality. Few works are referenced in literature concerning the estimation of the reliability of fluid journal bearings. This paper deals with a methodology to study the failure probability of a hydrodynamic journal bearing. An analytical approach is proposed to calculate static characteristics in using the Reynolds equation. The commonly methods used in structural reliability such as FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and Monte Carlo are developed to estimate the failure probability. The function of performance bounding two domains (domain of safety and domain of failure) is estimated for several geometrical configurations of a hydrodynamic journal bearing (long journal bearings with the hypotheses of Sommerfeld, Gümbel and Reynolds, and a short journal bearing with the hypothesis of Gümbel). http://hdl.handle.net/10985/8530 Reliability of a hydrostatic bearing CHARKI, Abdérafi; DIOP, Khadim; CHAMPMARTIN, Stephane; AMBARI, Abdelhak This paper presents a methodology for evaluating the failure probability of fluid bearings, which are sensitive components for the design of machine rotors, mechatronic systems, and high precision metrology. The static and dynamic behavior of a fluid bearing depends on several parameters, such as external load, bearing dimensions, supply pressure, quality of the machined surfaces, fluid properties, etc. In this paper, the characteristics of a simple geometry hydrostatic bearing are calculated analytically in order to demonstrate the usefulness of the methodology and its pertinence to bearing design. Monte Carlo simulation and first order reliability method (FORM) are used to evaluate the probability of failure. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/8530 2013-01-01T00:00:00Z CHARKI, Abdérafi DIOP, Khadim CHAMPMARTIN, Stephane AMBARI, Abdelhak This paper presents a methodology for evaluating the failure probability of fluid bearings, which are sensitive components for the design of machine rotors, mechatronic systems, and high precision metrology. The static and dynamic behavior of a fluid bearing depends on several parameters, such as external load, bearing dimensions, supply pressure, quality of the machined surfaces, fluid properties, etc. In this paper, the characteristics of a simple geometry hydrostatic bearing are calculated analytically in order to demonstrate the usefulness of the methodology and its pertinence to bearing design. Monte Carlo simulation and first order reliability method (FORM) are used to evaluate the probability of failure. http://hdl.handle.net/10985/10245 Conception D’un Palier Fluide Par Une Approche Mécano-Fiabiliste DIOP, Khadim; CHARKI, Abdérafi; CHAMPMARTIN, Stephane; AMBARI, Abdelhak Cet article présente une méthodologie pour l'évaluation de la probabilité de défaillance d'un palier de butée fluide. Ce type d’organe joue un rôle important dans la stabilité des rotors des machines, des systèmes mécatroniques et en métrologie de haute précision. Dans cet article, les caractéristiques d’une butée à géométrie simple sont calculées analytiquement afin de montrer d’une manière pratique l’intérêt de la nouvelle méthodologie proposée pour la conception d’un palier. L’approche repose sur un couplage mécano-fluido-fiabiliste. Les méthodes de simulation Monte Carlo et FORM (First Order Reliability Method) sont utilisées pour l'évaluation de la probabilité de défaillance. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/10245 2013-01-01T00:00:00Z DIOP, Khadim CHARKI, Abdérafi CHAMPMARTIN, Stephane AMBARI, Abdelhak Cet article présente une méthodologie pour l'évaluation de la probabilité de défaillance d'un palier de butée fluide. Ce type d’organe joue un rôle important dans la stabilité des rotors des machines, des systèmes mécatroniques et en métrologie de haute précision. Dans cet article, les caractéristiques d’une butée à géométrie simple sont calculées analytiquement afin de montrer d’une manière pratique l’intérêt de la nouvelle méthodologie proposée pour la conception d’un palier. L’approche repose sur un couplage mécano-fluido-fiabiliste. Les méthodes de simulation Monte Carlo et FORM (First Order Reliability Method) sont utilisées pour l'évaluation de la probabilité de défaillance.