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Sergey I. Zhavoronok - One of the best experts on this subject based on the ideXlab platform.
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anisotropic combined Dry Friction in problems of pneumatics dynamics
Journal of Vibration Engineering, 2020Co-Authors: Alexey A. Kireenkov, Sergey I. ZhavoronokAbstract:Traditionally used shimmy models assume vanishing slip at each point of a roadwheel contact spot, at the same time the observed instable wheel motion observed at unsteady rolling stages with significant sliding could not be described by traditional theories. Thus, a principally new model of the wheel shimmy is required to be consistent with such regimes. A new model of a rolling wheel accounting for the Dry Friction under the conditions of combined kinematics (i.e. simultaneous sliding, spinning and rolling) as well as for contact pressure distributions in pneumatic tires could become a background for various engineering methods of prediction of the shimmy appearing at unsteady rolling regimes. The proposed model of a pneumatic wheel’s motion is based on the improved Dry Friction theory accounting for the Friction anisotropy; the Coulomb law is assumed for each contact spot’s point where the summary slip velocity is resulted by the simultaneous sliding and spinning, and the contact pressure could be obtained from the finite element simulation of quasistatic tire deforming. The theory of the coupled Dry Friction is improved by accounting for the anisotropy of the Friction factor represented in a form of the second-rank tensor. The general formulation for the resultant vector of Dry Friction forces, Dry Friction torque and the rolling Friction couple are obtained. The contact pressure for a typical tire is computed numerically, its polynomial interpolation is introduced, and the coefficients of the approximate model of the Dry Friction are obtained. The constructed model allows an efficient accounting for the Dry Friction effects on the rolling stability as well as the real contact pressure distribution; thus, it can be interpreted as the second approximation improving the model of the shimmy of quasi-rigid wheel.
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Anisotropic Combined Dry Friction in Problems of Pneumatics’ Dynamics
Journal of Vibration Engineering & Technologies, 2019Co-Authors: Alexey A. Kireenkov, Sergey I. ZhavoronokAbstract:BackgroundTraditionally used shimmy models assume vanishing slip at each point of a roadwheel contact spot, at the same time the observed instable wheel motion observed at unsteady rolling stages with significant sliding could not be described by traditional theories. Thus, a principally new model of the wheel shimmy is required to be consistent with such regimes.PurposeA new model of a rolling wheel accounting for the Dry Friction under the conditions of combined kinematics (i.e. simultaneous sliding, spinning and rolling) as well as for contact pressure distributions in pneumatic tires could become a background for various engineering methods of prediction of the shimmy appearing at unsteady rolling regimes.MethodsThe proposed model of a pneumatic wheel’s motion is based on the improved Dry Friction theory accounting for the Friction anisotropy; the Coulomb law is assumed for each contact spot’s point where the summary slip velocity is resulted by the simultaneous sliding and spinning, and the contact pressure could be obtained from the finite element simulation of quasistatic tire deforming.ResultsThe theory of the coupled Dry Friction is improved by accounting for the anisotropy of the Friction factor represented in a form of the second-rank tensor. The general formulation for the resultant vector of Dry Friction forces, Dry Friction torque and the rolling Friction couple are obtained. The contact pressure for a typical tire is computed numerically, its polynomial interpolation is introduced, and the coefficients of the approximate model of the Dry Friction are obtained.ConclusionThe constructed model allows an efficient accounting for the Dry Friction effects on the rolling stability as well as the real contact pressure distribution; thus, it can be interpreted as the second approximation improving the model of the shimmy of quasi-rigid wheel.
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Implementation of analytical models of the anisotropic combined Dry Friction in problems of pneumatics’ dynamics
MATEC Web of Conferences, 2018Co-Authors: Alexey A. Kireenkov, Sergey I. ZhavoronokAbstract:An implementation of the theory of multi-component Dry Friction in some engineering problems of pneumatics’ dynamics is proposed. The main attention is devoted to the construction of analytical models of the combined Dry Friction accounting for the anisotropy of the Dry Friction coefficients and the real distribution of normal and tangent contact stresses. These models are applied for more detailed investigation of unsteady rolling regimes of pneumatics which are characterized by the non-vanishing sliding and spin.
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coupled Dry Friction models in problems of aviation pneumatics dynamics
International Journal of Mechanical Sciences, 2017Co-Authors: Alexey A. Kireenkov, Sergey I. ZhavoronokAbstract:Abstract The Dry Friction model accounting the combined kinematics is constructed using the differential Coulomb's law formulation for a small contact spot element. Integrating over the contact area results the exact dynamically coupled model that can be approximated by the one containing linear and quadratic forms of sliding and spinning velocities. The example of the real tire is studied using the finite element solution for the quasi-static contact pressure distribution; its analytic approximation allows one to compute the Dry Friction model coefficients. The effect of the contact pressure distribution on the Friction spin is shown.
Alexey A. Kireenkov - One of the best experts on this subject based on the ideXlab platform.
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anisotropic combined Dry Friction in problems of pneumatics dynamics
Journal of Vibration Engineering, 2020Co-Authors: Alexey A. Kireenkov, Sergey I. ZhavoronokAbstract:Traditionally used shimmy models assume vanishing slip at each point of a roadwheel contact spot, at the same time the observed instable wheel motion observed at unsteady rolling stages with significant sliding could not be described by traditional theories. Thus, a principally new model of the wheel shimmy is required to be consistent with such regimes. A new model of a rolling wheel accounting for the Dry Friction under the conditions of combined kinematics (i.e. simultaneous sliding, spinning and rolling) as well as for contact pressure distributions in pneumatic tires could become a background for various engineering methods of prediction of the shimmy appearing at unsteady rolling regimes. The proposed model of a pneumatic wheel’s motion is based on the improved Dry Friction theory accounting for the Friction anisotropy; the Coulomb law is assumed for each contact spot’s point where the summary slip velocity is resulted by the simultaneous sliding and spinning, and the contact pressure could be obtained from the finite element simulation of quasistatic tire deforming. The theory of the coupled Dry Friction is improved by accounting for the anisotropy of the Friction factor represented in a form of the second-rank tensor. The general formulation for the resultant vector of Dry Friction forces, Dry Friction torque and the rolling Friction couple are obtained. The contact pressure for a typical tire is computed numerically, its polynomial interpolation is introduced, and the coefficients of the approximate model of the Dry Friction are obtained. The constructed model allows an efficient accounting for the Dry Friction effects on the rolling stability as well as the real contact pressure distribution; thus, it can be interpreted as the second approximation improving the model of the shimmy of quasi-rigid wheel.
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Anisotropic Combined Dry Friction in Problems of Pneumatics’ Dynamics
Journal of Vibration Engineering & Technologies, 2019Co-Authors: Alexey A. Kireenkov, Sergey I. ZhavoronokAbstract:BackgroundTraditionally used shimmy models assume vanishing slip at each point of a roadwheel contact spot, at the same time the observed instable wheel motion observed at unsteady rolling stages with significant sliding could not be described by traditional theories. Thus, a principally new model of the wheel shimmy is required to be consistent with such regimes.PurposeA new model of a rolling wheel accounting for the Dry Friction under the conditions of combined kinematics (i.e. simultaneous sliding, spinning and rolling) as well as for contact pressure distributions in pneumatic tires could become a background for various engineering methods of prediction of the shimmy appearing at unsteady rolling regimes.MethodsThe proposed model of a pneumatic wheel’s motion is based on the improved Dry Friction theory accounting for the Friction anisotropy; the Coulomb law is assumed for each contact spot’s point where the summary slip velocity is resulted by the simultaneous sliding and spinning, and the contact pressure could be obtained from the finite element simulation of quasistatic tire deforming.ResultsThe theory of the coupled Dry Friction is improved by accounting for the anisotropy of the Friction factor represented in a form of the second-rank tensor. The general formulation for the resultant vector of Dry Friction forces, Dry Friction torque and the rolling Friction couple are obtained. The contact pressure for a typical tire is computed numerically, its polynomial interpolation is introduced, and the coefficients of the approximate model of the Dry Friction are obtained.ConclusionThe constructed model allows an efficient accounting for the Dry Friction effects on the rolling stability as well as the real contact pressure distribution; thus, it can be interpreted as the second approximation improving the model of the shimmy of quasi-rigid wheel.
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Implementation of analytical models of the anisotropic combined Dry Friction in problems of pneumatics’ dynamics
MATEC Web of Conferences, 2018Co-Authors: Alexey A. Kireenkov, Sergey I. ZhavoronokAbstract:An implementation of the theory of multi-component Dry Friction in some engineering problems of pneumatics’ dynamics is proposed. The main attention is devoted to the construction of analytical models of the combined Dry Friction accounting for the anisotropy of the Dry Friction coefficients and the real distribution of normal and tangent contact stresses. These models are applied for more detailed investigation of unsteady rolling regimes of pneumatics which are characterized by the non-vanishing sliding and spin.
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coupled Dry Friction models in problems of aviation pneumatics dynamics
International Journal of Mechanical Sciences, 2017Co-Authors: Alexey A. Kireenkov, Sergey I. ZhavoronokAbstract:Abstract The Dry Friction model accounting the combined kinematics is constructed using the differential Coulomb's law formulation for a small contact spot element. Integrating over the contact area results the exact dynamically coupled model that can be approximated by the one containing linear and quadratic forms of sliding and spinning velocities. The example of the real tire is studied using the finite element solution for the quasi-static contact pressure distribution; its analytic approximation allows one to compute the Dry Friction model coefficients. The effect of the contact pressure distribution on the Friction spin is shown.
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Theoretical and Experimental Modelling of the Combined Dry Friction Effects
IFAC Proceedings Volumes, 2012Co-Authors: Alexey A. KireenkovAbstract:Abstract It is presented phenomenological models of the sliding and spinning Dry Friction for the circle contact spots. These Dry Friction models permits to take into account both the dynamics coupling of the components defining force state and the more realistic representations about Dry Friction characteristics and the normal contact stresses distributions in the case of combined kinematics. Introduced models are based on the replacing of the exact integral models by the appropriate Pade expansions or Zhuravlev approximations. These Dry Friction models enable to describe adequately the relationship between force and kinematical characteristics over the entire range of angular and linear velocities. The approximate models preserve all analytical properties of the exact integrals models as functions of the kinematics parameters. Their coefficients are numbers that can be identified from experiments. Consequently, the models based on Pade or Zhuravlev approximations may be considered as phenomenological models of combined Dry Friction.
Francesco Sorge - One of the best experts on this subject based on the ideXlab platform.
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Rotor whirl damping by Dry Friction suspension systems
Meccanica, 2008Co-Authors: Francesco SorgeAbstract:An efficient and automatic attenuation technique for the whirling motion of rotating machinery can be achieved by supporting the journal boxes elastically and providing them with suitable rubbing surfaces subject to Dry Friction normal to the shaft axis. The critical flexural speeds are easily cut off and the whirl amplitude is minimized throughout the frequency range. Confining the usual operative angular speed of the rotor in the range of adhesive contact between the Dry Friction surfaces, there is no significant increase of power dissipation or heat production as a whole due to this type of suspension system, whose task is just to suppress the resonant peaks when passing the critical speeds. Moreover, the wear of the rubbing surfaces can be easily compensated by use of suitable spring loading systems for the Friction contact. The Dry Friction damping is also compared with an equivalent viscous damping, where the equivalence has to be understood in terms of work dissipated per single revolution of the rotor. As for other conventional cases, the shaft hysteresis is found to exert a destabilizing effect above the first critical speed, which however can be compensated by the other dissipation sources. The system stability is here studied perturbing the periodic motion and applying the Floquet theory.
J. B. Sokoloff - One of the best experts on this subject based on the ideXlab platform.
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Surface roughness and Dry Friction.
Physical Review E, 2012Co-Authors: J. B. SokoloffAbstract:Persson's multiscale contact mechanics theory combined with a multiscale Brillouin-Prandtl-Tomlinson model is used to show that on the basis of these models "Dry Friction" [i.e., kinetic Friction that remains at exceedingly small velocities (but still above the creep range) close to its value at higher velocities] should almost always occur for self-affine surfaces when the dominant interaction between two surfaces in contact is due to interatomic hard core repulsion, except for extremely smooth surfaces (i.e., surfaces with a Hurst index very close to 1).
Adnan Akay - One of the best experts on this subject based on the ideXlab platform.
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Relation of Dry-Friction to surface roughness
Journal of Tribology, 1997Co-Authors: M. T. Bengisu, Adnan AkayAbstract:A formulation of Friction force in the interface of a Friction pair is developed considering the mechanical components arising from the elastic and plastic deformations of the asperities and the chemical components represented by the adhesive forces between local contact regions. The results relate the normal load and Dry-Friction force to the relative normal and tangential velocities of a Friction pair as a function of asperity deformations and adhesive forces. It is shown that the important parameter in the relationship between normal load and the Dry-Friction force is the projection of the contact area in normal and tangential directions to the mean planes of contacting surfaces rather than the contact area itself. The two forms of Dry-Friction force derived from the statements of energy balance at the interface allow alternate approaches to modelling of the Friction between interacting rough surfaces.
