Трение и износ, 1999, Vol.20, No.3
/ Издания академии / Научные журналы
Трение и износ, 1999, Vol.20, No.3
Том 20, номер 3; май-июнь, 1999
СОДЕРЖАНИЕ
СТАТЬИ
Goryacheva I.G.
Determination of contact characteristics with the account of the parameters of surface macro- and microgeometries. pp. 239--248
Summary: A method is proposed how to determine the nominal and actual pressures in the contact region during interactions between macrobodies with the account of their surface microrelief. The method is based on plotting the additional displacement function using model ideas about the surface microrelief and the analysis of the discrete contact problem for the elastic semispace with the account of the mutual effect of contact spots. An example shows how to determine the additional displacement function and contact characteristics for some specific cases by determining the macroshapes of interacting bodies and the parameters of their surface microgeometries (the shapes of roughnesses and their three-dimensional arrangement).
Bufeev V.A.
Phenomenon of tangential friction and conditions of its observation. Part II. pp. 249--256
Summary: A feasibility is discussed of investigating tangential triboeffects among entirely different friction couples and conditions of their manifestation during friction between entirely different materials which may may make the effects stronger and easily observable. It is demonstrated that the magnitude of a tangential triboeffect can be comparable with the traditional normal Coulomb friction.
Evtushenko A.A., Ivanik E.G.
Formulas for calculating mean temperatures and wear of friction surfaces in braking. pp. 257--264
Summary: Analytical expressions have been derived to evaluate the temperature and wear of the working members of friction brakes. The friction coefficient in the process of braking is assumed constant, while the wear resistance coefficient is the linear function of contact temperature. Regularities of distribution of the temperature and wear have been studied as a function of the input parameter characterizing load variations from zero to the nominal.
Kadomtsev I.G.
Elastoplastic axisymmetric collisions of massive bodies. pp. 265--269
Summary: A quasistatic approach has been used to analyze the elastoplastic collisions of massive bodies. An earlier constructed model of local crumpling of axisymmetric elastoplastic bodies takes into consideration the flow of material from the contact zone, the extent of plastic deformation is taken into account since the moment of friction and the mean pressure in the contact zone reach the Brinell value. The proposed theory yields good correlation of the basic parameters of collisions with the reported experimental results.
Balakin V.A., Sergienko V.P.
Calculation of heat generated in passenger car brakes. pp. 270--281
Summary: Formulas are demonstrated for calculating intensive friction-induced heat generation, heat fluxes and mean temperature fields in disk and drum brakes. The results support sound prospects for introducing "ventilated" brakes.
Dzhanakhmedov A.Kh., Vagidov M.A., Ejvazova Z.E., Dzhanakhmedov E.A.
Tribological fundamentals of generalized calculations of braking devices and friction gears with flexible coupling. pp. 282--287
Summary: A theoretical calculation of braking devices and friction gears with flexible coupling has been performed and generalized in order to take into account the proper weight of the coupling and the effects of randomly directed concentrated force factors pressing the flexible member against various points of the circular rim. A differential equation is derived describing the formulated problem. Aformula has been obtained allowing to determine the force of elongation in any cross section of the flexible coupling, the Euler formula being a particular case. Another formula has been derived to calculate the braking torque achieved by the studied friction couple. The obtained calculated dependencies have been validated with the software and the results are summarized in the attached plots.
Nazarov A.D.
Theoretical principles and experimental analytical method of determination of the effect of the total unbalanced weight of crank parts upon the life of engines. pp. 288--299
Summary: Theoretical principles and a method have been developed together with the formulas for calculating the effect of the total unbalanced weight of the crank parts upon the life of engines. It is demonstrated that it is sufficient to know the constants for each engine design and model and the coefficients determined using the experimental data in order to understand the regularities with which the life of engines changes as a function of the total unbalanced weight. An experimental analytical method is advanced to determine the life of engines as the function of the total unbalanced weight of crank parts by performing accelerated stand and operation tests. It has been established that the experimental analytical values and experimental results are practically identical. It is demonstrated that it is sufficient to determine the total unbalanced weight experimentally in three specific points in order to evaluate its effect upon the variations of the relative life of engines and to reveal the regularities. For each engine design and model these points correspond to definite total unbalanced weight parameters of the crank parts. The experimental and analytical method reduces expenses for studies of the above regularities 2.4--3.3 times.
Tarasov V.V.
Simulation of anisotropic friction. pp. 300--305
Summary: A mechanical model is proposed which simulates basic regularities of the anisotropic friction process facititating its studies.
Zharov I.A., Komarovskii I.A., and Zakharov S.M.
Regularities of wear in rolling with transverse slippage. pp. 306--312
Summary: A number of regularities has been revealed in rolling friction with transverse slippage. It is demonstrated that the wear rate in each point of the contact spot is directly proportional to the product of pressure and the squared relative slippage in the point. It is corroborated that the wear mechanism has the nature of multicycle fatigue. It has been established that the effect of the hardness of a rubbing surface is strongly determined by the type of wear.
Voronin N.A.
Topocomposites -- a new class of structural material for triboengineering applications. Part I. (Methodological problems of development and designing). pp. 313--320
Summary: The term of a new class of materials for triboengineering applications is proposed to designate topocomposites. The methods of their fabrication and the materials needed are briefly reviewed,
Shevelya V.V., Kalda G.S.
Fretting effect upon resistance of metals to fatigue. Part II. Combination tests. pp. 321--324
Summary: The combined tests on fatigue durability in conditions of fretting-corrosion of armco-iron, steels 45 and 30ХГСА, duralumin Дl6Т are carried out. The influence of duration of contact interaction and contact pressure on residual endurance of metal was investigated.
Chaus A.S.
The effect of modification and alloying upon the wear resistance of cast high-speed steels. pp. 325--332
Summary: The effect of modification and alloying upon the structure and properties of cast high-speed steels, such as P6M5K3 has been studied. A relationship has been established between the structural parameters, phase composition, mechanical behavior, wear rate and its pattern. It is demonstrated that the wear of steels with high triboengineering characteristics is governed by the abrasive mechanism and the wear of steels with poor characteristics is governed by the mechanisms of abrasion and adhesion. The structural factor dominates in abrasion, meanwhile the steel chemical composition governs in adhesion.
Kharlamov V.V., Zolotukhina L.V., Frishberg I.V., Kishkoparov N.V.
Mass transfer in sliding tribocouples lubricated with ultradispersed Cu--Sn alloy powder. pp. 333--338
Summary: The effect of intensification of the mass transfer in the sliding tribocouple lubricated with the ultradispersed Cu--Sn powder is analyzed. It has been established that a small dose of the powder added to the base oil reduces the wear rate 3 to 3.5 times and allows to double the scratching load.
Gorokhovskii G.A., Vasilevskii E.T., Timchenko P.N.
Tribochemical causes of spontaneous loosening of nuts on threaded joints. pp. 339--347
Summary:
Threaded joints are treated as heterogeneous, synergetic metal organic systems having working surfaces coated with fine films of organic compounds. Such systems fully lack all thermodynamic equilibrium. The product of mechanical cracking of the organic films causes spontaneous loosening of the nuts. A mechanochemical method is proposed to stabilize friction at rest in order to make threaded joints more reliable.
ЛЮДИ НАУКИ
Marat A. Bronovets (60 years since Birthday). pp. 348--349
ADVERTISEMENT p. 350
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Created with assistance of Dr. Ignatii I. Korsak
Copyright © 1999 The National Academy of Sciences of Belarus
Copyright © 1999 The V.A.Biely Institute of Mechanics of Metal-Polymer Systems
