Трение и износ, 1996, Vol.17, No.3

Трение и износ, 1996, Vol.17, No.3

ТРЕНИЕ И ИЗНОС
Международный научный журнал
Published by INFOTRIBO Ltd., Gomel, Belarus

Том 17, номер 3; май-июнь, 1996

СОДЕРЖАНИЕ

СТАТЬИ

Airapetov Ye. L., Panovko M. Ya.
Influence of single irregularities on spatial elastohydrodynamic contact. pp. 279--286
Summary: A method of numerical analysis of heavy-loaded spatial elastohydrodynamic contact is presented. This method is based upon the Newton--Raphson algorithm for solving nonlinear equations describing the contact, the finite difference approximation, and the complementarity conditions to locate the free boundary. A numerical simulation of sliding EHD point contact having a stationary surface irregularity (bump or dent) was carried out under isothermal conditions. A significant influence of the surface irregularities on pressure and film thickness in a contact as well as on subsurface octahedral shear stresses was shown.

Barykin N. P., Galimov A. K.
Mathematical simulation of multi-layer lubricating coating flow in metal forming. pp. 287--291
Summary: Mathematical model is developed of multi-layer composite lubricant flow with account for viscous and plastic properties of the substrate in metal forming. The model allows for determining conditions for stable hydrodynamic lubrication, as well as estimating lubricant rheological properties. It can be also used in algorithms of optimizing manufacturing control over the deformable article service life.

Bogdanov R. I., Varnavin S. V., Nagornykh S. N.
Nonlinear behavior of friction coefficient of metals. pp. 292--297
Summary: One differentiable classification of phase velocity vector fields on the optimal planes is used to predict some features of nonlinear friction behavior for metals.

Voitov V. A., Isakov D. I.
Modelling of boundary lubrication in tribosystems. I. Technique of physical modelling. pp. 298--306
Summary: The technique of physical modelling of friction under conditions of boundary lubrication is presented. This methodology permits to define the tribological characteristics of real friction systems applying the test results of tribosystem model, on the base not only dimensional change but also working conditions, kinematic schemes, materials of friction units, and lubrication.

Voyachek A. I.
Estimation of coefficients of normal and tangential compliance of a layer composed of two materials contacting over a random surface. pp. 307--311
Summary: An estimation of normal and tangential compliance has been made for a layer composed of two unlike homogeneous and isotropic materials in mutual contact over a random surface throughout the entire layer. Computations have shown the effect of surface roughness parameters on the magnitudes of the coefficients.

Grylitskii D. V., Krasnyuk P. P.
Stationary thermoelastic contact of two cylinders with frictional heat generation. pp. 312--319
Summary: The axi-symmetrical problem for two circular unlimited cylinders with frictional heat generation on the common axis is investigated. By Fourier integral transform the integral for the contact pressure is obtained. It is shown that the pressure distribution depends on the distribution of the external load. Effect of the input parameters on the contact pressure is studied.

Kuzmin N. N., Feldshtein I. V.
Some approaches to tribosystem simulation. pp. 320--325
Summary: Various approaches to tribosystem simulation are discussed. The restrictions inherent to specific techniques are highlighted, including physical limitation on forecast time for any dynamic model due to the chaotic nature of friction. The physics of nonlinear nonequilibrium systems has been applied to assess the dynamic behavior of tribosystems, space dimension of their embedding, the correlation dimension, and the first Lyapunov exponent for various loading parameters. An example of reconstruction of the attractor of a tribosystem is demonstrated in an artificial phase space.

Ryzhov Ye. V., Khokhlov V. M.
Prediction of surface roughness in elastic contact. pp. 326--330
Summary: New method and formulas for roughness prediction at elastic contact of machine parts have been developed. Application of the formulas is presented. It was found out that maximum elastic deformation of roughness is equal to R_p value. Maximum deformation in a contact of rough surfaces cannot exceed double R_p value.

Soldatenkov I. A.
Theoretical prediction of wear for Winkler-type viscoelastic coating. pp. 331--339
Summary: Contact between a moving indenter and viscoelastic coating is considered. Substrate compliance and coating wear are taken into account and they are shown to produce an essential influence on the contact.

Chernets M. V.
Durability of cylindrical sliding tribosystems with boundaries close to circular. pp. 340--344
Summary: A method of approximate solution for cylindrical sliding system, which elements have a small out-of-roundness has been presented. A model of sliding, contact pressure calculation method and lobing description have been considered. In a general solution lobing, kinematics of elements, different strength and frictional properties of materials have been taken into account. Numerical solution has been also presented for sliding bearing.

Godlevskii V. A., Volkov A. V., Latyshev V. N., Maurin L. N.
Model of lubricating action of surfactant solution in cutting. pp. 345--351
Summary: The process of the surfactant's physical adsorption on the contact areas in the system tool -- worked material during machining is one of the several stages of multiphasic lubrication process realized in the interface capillary system. The high temperature in cutting zone leads to evaporation of liquid lubricants during the first moment of their contact with metal. The mathematical model describing simultaneously diffusion and adsorption of active components of gaseous environment inside the single capillary is proposed. The parameters of the model connected with surface-active additives efficiency were determine.

Zharov I. A.
Movement of abrasive particle between surfaces. pp. 352--356
Summary: Based on cylinder and sphere models the velocity of an abrasive particle relative to the surfaces and its tying-up moment are determined. It is found that if the particle moves without rotation then the velocities are approximately equal and vary stepwise at embedding.

Kallas P. K.
Energy of abrasive wear of metals. pp. 357--364
Summary: The specific and relative energies of abrasive wear are considered as functions of metal hardness. It is demonstrated the relative wear of technically pure metals and annealed steels little depends on their hardness and is the least at friction against fixed abrasives. A single experiment with these materials allows to determine the range of variations of the specific energy of materials wear under given test conditions. Hardening and heat treatment of metals reduce the relative energy of wear. The specific energy for the mechanical abrasion varies within 1--5000 J/mm³.

Markova L. V., Semenyuk M. S.
Main trends in developing methods and built-in devices for wear diagnosis of tribosystems. pp. 365--370
Summary: The paper reviews the methods and devices for wear diagnosis of the tribosystems by wear debris analysis. The classification of on-line and in-line devices is carried out. Magnetic accumulation of debris is shown to be widely used for condition monitoring. The possible designs of devices installation in lubrication system of machine are presented.

Krasnov A. P., Makina L. B., Panov S. Yu., Mit V. A.
Peculiarities of friction surface formation of aliphatic polymers. pp. 371--373
Summary: The structure of the surface layers of UHMWPE and PA-6 at friction is investigated. It is found that under the conditions studied, the process of the friction surface self-organization includes active mass transfer from the surface to the underlying layers in addition to orientation of the polymer chains in direction of friction. As the result, the surface layers of nanometer thickness of the aliphatic polymers are formed by the particles with lower surface energy.

Lozovoi Yu. A., Zaimovskaya T. A., Kuz'mina G. N., Parenago O. P.
Aftereffect of tribological additives under high loads and the method for its determination. pp. 374--381
Summary: Aftereffect as a phenomenon of prolongated action of tribological additives to oils being the result of chemical modification of friction surfaces was considered. A novel approach to this effect identification and quantitative determination with four-ball tribometer was developed. The method was used to study the common additives reducing friction and wear. For these additives measurements of aftereffect under various conditions of tribological tests were carried out. It was shown that the aftereffect increases with both higher loads and higher concentration of additives in oil.

Okhlopkova A. A., Vinogradov A. V.
Wear resistance and strain-strength performance of polytetrafluoroethylene containing ultradispersed oxides and nitrides of metals. pp. 382--385
Summary: Tribological behavior and strain-strength performance of polytetrafluoroethylene filled with oxides and nitrides of transition metals, such as aluminum, silicon, titanium, and chromium, have been investigated. It is demonstrated that the behavior of the composites strongly depends upon the modifications of the supermolecular structure of the polymeric matrix. The oxides of the metals favor the appearance of two levels in the supermolecular structure differing by the size of spherulites. This structural anisotropy explains the variations of wear resistance and strength of the PTFE-based composites.

Struk V. A., Bogdanovich P. N., Ovchninikov E. V., Gubanov V. A., Boiko Yu. S.
Effect of structure of fluorine-containing oligomers on friction at low velocities. pp. 386--390
Summary: Tribological behavior of metal--metal and metal--polymer pairs with treating fluorine-containing oligomers have been investigated. Antifriction properties are related to structure of fluorine-containing oligomers.

ОБЗОРЫ

Rodnenkov V. G.
Studies in tribological behavior of liquid crystals. Part II. Tribology of oils modified by liquid crystals. pp. 391--401
Summary: The paper reviews the studies of the tribological behavior of oils modified by liquid crystals, specifically the solubility of liquid crystals in mineral and synthetic oils and the rheological properties of the latter. It is demonstrated that liquid crystals, irrespective of their type improve the antifrictional behavior of oils. A relationship has been established indicating that the molecular structure of oils with these additives governs their lubricating action. The concentration of a liquid crystal additive in an oil determines the moment of a coefficient of friction decrease and roughness decrease.

Shilko S. V.
Experimental and calculation-experimental methods for evaluation of contact stresses. Part 2. pp. 402--411
Summary: A review of hybrid (theoretical--experimental) methods for contact pressure determination, based on stress state analysis (reconstruction) and measuring integral contact characteristics or mathematical identification of sensor parameters for making more precise measuring results is given. Two original methods representing both methodologies are discussed.

КОРОТКИЕ СООБЩЕНИЯ

Prushak V. Ya., Sviridov N. V., Konoplyanik A. I., Melixetyan N. G.
Calculation of high-temperature wear of brake materials. pp. 412--416
Summary: Model is presented of failure of braking pads. Calculational algorithm is proposed and dependence of worn layer thickness on time is given.

ЛЮДИ НАУКИ

Анатолий Иванович Свириденок (К 60-летию со дня рождения). С. 417--418
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КАЛЕНДАРЬ КОНФЕРЕНЦИЙ. pp. 419--420.

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Designed and maintained by Dr. Nikolai N. Kostyukovich. Last updated: October 10, 1998
Created with assistance of Dr. Ignatii I. Korsak
Copyright © 1996-1998 The National Academy of Sciences of Belarus