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  • 1. Alemani, Mattia
    et al.
    Nosko, Oleksii
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Metinoz, Ibrahim
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A study on emission of airborne wear particles from car brake friction pairs2015In: SAE International Journal of Materials & Manufacturing, ISSN 1946-3979, E-ISSN 1946-3987, Vol. 9, no 1, p. 147-157, article id 2015-01-2665Article in journal (Refereed)
    Abstract [en]

    The emission of airborne wear particles from friction material / cast iron pairs used in car brakes was investigated, paying special attention to the influence of temperature. Five low-metallic materials and one non-asbestos organic material were tested using a pin-on-disc machine. The machine was placed in a sealed chamber to allow airborne particle collection. The concentration and size distribution of 0.0056 to 10 μm particles were obtained by a fast mobility particle sizer and an optical particle sizer. The temperature was measured by a thermocouple installed in the disc. The experiments show that as the temperature increases from 100 to 300 °C the emission of ultrafine particles intensifies while that of coarse particles decreases. There is a critical temperature at which the ultrafine particle emission rate rises stepwise by 4 to 6 orders of magnitude. For the friction pairs investigated, the critical temperature was found to be between 165 and 190 °C. Below the critical temperature, fine particles outnumber coarse and ultrafine particles, although coarse particles make up the bulk of the particulate matter mass. The friction pairs differ in the ultrafine particle emission rate by 1 to 2 orders of magnitude. Above the critical temperature, ultrafine particles constitute almost 100% of the total particle number and their relative mass contribution can exceed 50%. Analysis of the particle size distributions revealed peaks at 0.19-0.29, 0.9 and 1.7 μm. Above the critical temperature, one more peak appears in the ultrafine particle range at 0.011-0.034 μm.

  • 2. Belyakov, Nikolay
    et al.
    Nosko, Oleksii
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Analytical solution of non-stationary heat conduction problem for two sliding layers with time-dependent friction conditions2016In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 98, p. 624-630Article in journal (Refereed)
    Abstract [en]

    In this article we conduct an overview of various types of thermal contact conditions at the sliding interface. We formulate a problem of non-stationary heat conduction in two sliding layers with generalized thermal contact conditions allowing for dependence of the heat-generation coefficient and contact heat transfer coefficient on time. We then derive an analytical solution of the problem by constructing a special coordinate integral transform. In contrast to the commonly used transforms, e.g. Laplace or Fourier transforms, the one proposed is applicable to a product of two functions dependent on time. The solution is validated by a series of test problems with parameters corresponding to those of real tribosystems. Analysis shows an essential influence of both time-dependent heat-generation coefficient and contact heat transfer coefficient on the partition of the friction heat between the layers. The solution can be used for simulating temperature fields in sliding components with account of this influence.

  • 3. Belyakov, N.S.
    et al.
    Nosko, A.P.
    Heat frictional contact of semi-bounded solids2008In: Motorization and Power Industry in Agriculture, ISSN 1730-8658, Vol. 10A, p. 83-91Article in journal (Refereed)
  • 4. Belyakov, N.S.
    et al.
    Nosko, A.P.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.). Bauman Moscow State Technical University, , Russian.
    Mathematical simulation of thermal friction processes under conditions of nonideal contact2009In: High Temperature, ISSN 0018-151X, E-ISSN 1608-3156, Vol. 47, no 1, p. 123-130Article in journal (Refereed)
    Abstract [en]

    Analytical solutions are obtained for problems on unsteady-state thermal conductivity under conditions of nonideal frictional contact of two solid isotropic half-bounded bodies for cases such as a system of two half-spaces, a system of two unbounded cylindrical bodies, and a system of two half-spaces in the presence of volume source of heat release.

  • 5. Belyakov, N.S.
    et al.
    Nosko, A.P.
    Nonperfect thermal contact of friction bodies2010Book (Refereed)
  • 6. Belyakov, N.S.
    et al.
    Nosko, A.P.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.). Bauman Moscow State Technical University, Russian.
    Thermoelastic Problem of Friction of Plane-Parallel Layers with Allowance for Nonstationarity of Thermal Processes2010In: Journal of Friction and Wear, ISSN 1068-3666, Vol. 31, no 5, p. 317-325Article in journal (Refereed)
    Abstract [en]

    An unbound quasistatic thermoelasticity problem of the friction of plane-parallel layers with allowance made for their wear is considered. The exact solution of the problem for the transient thermal contact of layers is obtained. The criteria of the thermal-force stability of a tribosystem for various thermal models are studied.

  • 7. Belyakov, N.S.
    et al.
    Nosko, A.P.
    Математическое моделирование неидеального теплового контакта тел трения2008In: 6th Minsk International Heat and Mass Transfer Forum, 2008Conference paper (Refereed)
  • 8. Nosko, A.L.
    et al.
    Belyakov, N.S.
    Nosko, A.P.
    Bauman Moscow State Technical University, Russian Federation .
    Application of the generalized boundary condition to solving thermal friction problems2009In: Journal of Friction and Wear, ISSN 1068-3666, Vol. 30, no 6, p. 455-462Article in journal (Refereed)
    Abstract [en]

    A new generalized boundary condition is advanced to describe the nonideal thermal contact in the tribosystem body-counterbody with high heat conductivity. The solutions of one-dimensional problems of nonstationary heat conductivity in half-bounded and bounded bodies with a generalized boundary condition are presented. The applicability of this condition to simulation of the contact temperature is exemplified by the polymer-metal tribosystem.

  • 9. Nosko, A.L.
    et al.
    Mozalev, V.V.
    Nosko, A.P.
    Saitama University, Japan .
    Suvorov, A.V.
    Lebedeva, V.N.
    Calculation of temperature of carbon disks of aircraft brakes with account of heat exchange with the environment2012In: Journal of Friction and Wear, ISSN 1068-3666, Vol. 33, no 4, p. 233-238Article in journal (Refereed)
    Abstract [en]

    The temperature of the tribosurface of aircraft-brake carbon disk during braking is studied. Formula is advanced to calculate the temperature based on the geometrically one-dimensional unsteady heat model taking into account the convective heat exchange of the lateral surfaces of the disk with the air environment. Friction experiments with lab specimens made from the carbon material Termfar-ADF demonstrate the temperature variations. The experimental results are compared with the calculated results.

  • 10. Nosko, A.L.
    et al.
    Nosko, A.P.
    Bauman State Technical University, Russia.
    Modeling of thermoelastic frictional contact2007In: Journal of Friction and Wear, ISSN 1068-3666, Vol. 28, no 4, p. 338-341Article in journal (Refereed)
    Abstract [en]

    A model of thermoelastic frictional interaction based on nonideal thermal contact under friction of a corrugated elastic solid on an absolutely flat rigid solid is developed. The proposed model may be used for the estimation of the capability and durability of tribological conjunctions of the type frictional polymer material-metal.

  • 11. Nosko, A.L.
    et al.
    Nosko, A.P.
    Solution of contact heating problem with account for heat transfer between the friction members2006In: Journal of Friction and Wear, ISSN 1068-3666, Vol. 27, no 3, p. 35-40Article in journal (Refereed)
  • 12. Nosko, A.L.
    et al.
    Nosko, A.P.
    Исследование охлаждения тормозных устройств ПТМ2005In: Herald of the Bauman Moscow State Technical University. Mechanical Engineering, ISSN 0236-3941, no 3, p. 88-99Article in journal (Refereed)
  • 13. Nosko, A.L.
    et al.
    Nosko, A.P.
    Исследование термоупругого контактного взаимодействия в трибосопряжениях2007In: Herald of the Bauman Moscow State Technical University. Mechanical Engineering, ISSN 0236-3941, no 2, p. 71-81Article in journal (Refereed)
  • 14. Nosko, A.L.
    et al.
    Nosko, A.P.
    Математическое моделирование трибологических систем (применительно к тормозным устройствам ПТМ)2006In: Herald of the Bauman Moscow State Technical University. Mechanical Engineering, ISSN 0236-3941, no 1, p. 83-98Article in journal (Refereed)
  • 15. Nosko, A.L.
    et al.
    Nosko, A.P.
    Расчет нагрева тормозных устройств ПТМ2007In: Construction and Road Building Machinery, ISSN 0039-2391, no 3, p. 38-43Article in journal (Refereed)
  • 16. Nosko, A.L.
    et al.
    Nosko, A.P.
    Решение фрикционной тепловой задачи с учетом термической проводимости контакта2006In: Problems of Tribology, ISSN 2079-1372, no 4, p. 75-77Article in journal (Refereed)
  • 17. Nosko, A.L.
    et al.
    Nosko, A.P.
    Тепловые процессы в узлах трения машин2005In: Proceedings of Higher Educational Institutions. Мachine Building, ISSN 0536-1044, no 11, p. 3-9Article in journal (Refereed)
  • 18. Nosko, A.L.
    et al.
    Nosko, A.P.
    Технико-экономические расчеты при выборе колодочных тормозных устройств ПТМ2007In: Russian Journal of Heavy Machinery, ISSN 0131-1336, no 10, p. 35-39Article in journal (Refereed)
  • 19. Nosko, A.L.
    et al.
    Nosko, A.P.
    Численное моделирование трибологических систем (применительно к тормозным устройствам ПТМ)2005In: Proceedings of Higher Educational Institutions. Мachine Building, ISSN 0536-1044, no 12, p. 8-17Article in journal (Refereed)
  • 20. Nosko, A.L.
    et al.
    Nosko, O.
    Вплив фрікційно-спрацьовувальних показників на функціональні можливості гальм ПТМ2005In: Mashynoznavstvo, ISSN 1729-4959, no 4, p. 22-25Article in journal (Refereed)
  • 21.
    Nosko, A.P.
    Bauman State Technological University,Russian Federation .
    Selection of a contact geometry model when simulating thermal friction processes2009In: Journal of Friction and Wear, ISSN 1068-3666, Vol. 30, no 2, p. 127-136Article in journal (Refereed)
    Abstract [en]

    In this paper an analysis of the uniformity of temperature distribution on the surface of a semi-infinite friction body, mutual heat interference of discrete contact areas, and the accuracy of the concentrated model of thermal and mechanical contact of rubbing solids in response to the degree of contact discreteness is conducted. The conducted research yields a criterion of selection for the contact geometry model. A classification of heat friction problems that allows the selection of an appropriate model of contact geometry for simulation of heat friction processes is proposed.

  • 22. Nosko, A.P.
    Метод расчета температур в области контакта элементов пар трения тормозных устройств ПТМ2010Doctoral thesis, monograph (Other academic)
  • 23.
    Nosko, Oleksii
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Analytical Study of Sliding Instability due to Velocity- and Temperature-Dependent Friction2016In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 61, no 2, p. 1-10Article in journal (Refereed)
    Abstract [en]

    The instability of sliding causes deterioration of performance characteristics of tribosystems and is undesired. To predict its occurrence, the motion of a body of a one-degree-of-freedom system with friction is investigated about the steady sliding equilibrium position. The motion equation is formulated with the friction coefficient dependent on the sliding velocity and contact temperature changing due to transient heat conduction in the body. An analytical expression for the body motion is derived using the Laplace integral transform. It is shown that the sliding instability can manifest in the form of deviation of the body from the equilibrium position or in the form of oscillation. The instability conditions containing the friction–velocity and friction–temperature slope coefficients are obtained. Positive friction–temperature slope results in the deviation of the body from the equilibrium position. At negative friction–temperature slope, both types of the sliding instability can occur. The proposed instability conditions agree well with existing theoretical concepts and can be useful when designing tribosystems.

  • 24. Nosko, Oleksii
    Calculation of temperatures under dry friction of bodies: Discreteness and thermal imperfectness of friction contact2011Book (Refereed)
  • 25. Nosko, Oleksii
    Effect of temperature on dynamic characteristics of a pad sliding on a disc2013Doctoral thesis, monograph (Other academic)
  • 26.
    Nosko, Oleksii
    Saitama University, Japan .
    Partition of friction heat between sliding semispaces due to adhesion: deformational heat generation2013In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 64, p. 1189-1195Article in journal (Refereed)
    Abstract [en]

    Analytical expressions of heat-partition coefficient and contact temperatures for two sliding semispaces with account for adhesion-deformational heat generation and contact heat exchange have been obtained. The rate of deformational heat generation is assumed to decay exponentially with increase of distance from the interface. It has been shown that heat-generation configuration and the intensity of contact heat exchange have impact on heat partition only within a transient interval. The features of perfect thermal contact have been analyzed. Perfect thermal contact implies variation of heat partition in time. Heat partition and contact temperature for a semispace, sliding over a semispace with a constant temperature, have been studied. Adhesion-deformational heat generation results in a change of the direction of surface heat flow.

  • 27.
    Nosko, Oleksii
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Alemani, Mattia
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Temperature effect on emission of airborne wear particles from car brakes2015In: Europe's Braking Conference and Exhibition 2015, 2015, Vol. EB2015-TEF-014Conference paper (Refereed)
  • 28.
    Nosko, Oleksii
    et al.
    Saitama University, Japan .
    Nagamine, T.
    Mori, H.
    Sato, Y.
    Theoretical study of thermofrictional oscillations due to negative friction-temperature characteristic2013In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 61, p. 235-243Article in journal (Refereed)
    Abstract [en]

    Analytical study on oscillations of a body on a moving counterbody has been done by assuming imperfect frictional thermal contact and friction that decreases with contact temperature. It has been shown that stick-slip oscillation occurs due to decrease of friction coefficient when the body moves in the opposite direction to the counterbody. Dynamical characteristics, such as conditions for stable sliding and limit cycles, have been studied. Normal force between the bodies has significant effect on sliding stability.

  • 29.
    Nosko, Oleksii
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Nagamine, T.
    Nosko, A. L.
    Romashko, A. M.
    Mori, H.
    Sato, Yuichi
    Measurement of temperature at sliding polymer surface by grindable thermocouples2015In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 88, p. 100-106Article in journal (Refereed)
    Abstract [en]

    This paper is devoted to experimental study of capabilities and limitations of grindable thermocouples as applied to polymer materials sliding on metal. Chromel-alumel and chromel-copel grindable thermocouples have been developed and tested for wide ranges of contact pressure and sliding velocity. The background temperature of the sliding surface can be determined as the lower envelope of the signal from the grindable thermocouple. Steady and unsteady regimes of sliding have been investigated. For steady sliding, the accuracy of the temperature determination increases with measurement duration. In the case of unsteady sliding, accurate temperature determination requires multiple tests under the same conditions. The thickness of the thermocouple junction has been analyzed for correct comparison of experimental and calculated temperatures.

  • 30.
    Nosko, Oleksii
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Nagamine, Takuo
    Mori, Hiroki
    Sato, Yuichi
    Friction-induced oscillations of a non-asbestos organic pin sliding on a steel disc2015In: Acta Mechanica et Automatica, ISSN 1898-4088, Vol. 9, no 2, p. 84-88Article in journal (Refereed)
    Abstract [en]

    Friction-induced oscillations result in deterioration of performance of disc brakes and are generally undesired. We conduct experimental study of friction-induced oscillations in a non-asbestos organic material/steel pair used in disc brakes of motor vehicles. The tests are done by use of a pin-on-disc machine in which the pin sample is supported on a deformable beam. The adjustable friction parameters are the disc velocity, contact pressure and temperature. The tests show that the friction coefficient decreases with the sliding velocity and increases with the temperature. The friction-induced tangential oscillation of the pin sample occurs with a frequency equal to the first natural frequency of the beam. The effects of the disc velocity and temperature on the oscillation characteristics are investigated. The oscillation amplitude increases with the disc velocity on the interval of velocities below 2 m/s. Temperature changes of several tens of degrees Celsius lead to the oscillation occurrence/decay. The obtained results can be useful for prognostication of friction-induced oscillations in disc brakes with non-asbestos organic pads.

  • 31.
    Nosko, Oleksii
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Effective density of airborne wear particles from car brake materials2017In: Journal of Aerosol Science, ISSN 0021-8502, E-ISSN 1879-1964, Vol. 107, p. 94-106Article in journal (Refereed)
    Abstract [en]

    People living in urban environments are subject to high health risks due to various anthropogenicsources of airborne particulate matter, including wear of transport vehicle brakes. Studies ofairborne particles often require an estimate of the effective particle density, a property thatallows correct matching of mass and size characteristics measured by different aerosolinstruments. In this study we investigated the effective density of airborne wear particles emittedfrom car brake materials. The particles were generated by a pin-on-disc machine located in asealed chamber. Two methods were used to determine the effective density. The first method isbased on measurements of PM10 and particle size distribution. The second method involvesmeasurements and subsequent fitting of the mobility size distribution and aerodynamic sizedistribution. Results from the two methods showed good agreement. It was found that theeffective density is 0.75±0.2 g/cm3. The particle emission, size distribution and effectivedensity are sensitive to temperature variations. An intensive emission of ultrafine particles isinitiated at the disc temperature of 185±16 °C. The effective density decreases with thetemperature in the interval 110–360 °C. There is a large difference between the effective densityand the density of the particle material, which suggests that the particles are porous.

  • 32.
    Nosko, Oleksii
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Quantification of ultrafine airborne particulate matter generated by the wear of car brake materials2017In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 374-375, p. 92-96Article in journal (Refereed)
    Abstract [en]

    The wear of car brakes is one of the main sources of airborne particulate matter in urban environments. Ultrafine wear particles are of special environmental interest since they can easily penetrate the human body through inhalation and cause various diseases. In the present study, the contribution of ultrafine particles to airborne particulate matter emitted from car brake materials was investigated under different friction conditions. Particles were generated using a pin-on-disc machine located in a sealed chamber and analysed in terms of number, volume and mass concentrations. It was found that temperature has a strong influence on the size distribution of the emitted particles. At temperatures below 200 °C, the ultrafine particles make no measurable contribution to the mass concentration of airborne particles with diameters smaller than 10 µm (PM10). However, at temperatures above 200 °C, the mass fraction of the ultrafine particles in PM10 reaches tens of percent. In general, this fraction increases with the temperature and decreases with the sliding duration. The mass contribution of ultrafine wear particles to PM10 is substantial, and it should not be neglected in environmental and tribological studies.

  • 33.
    Nosko, Oleksii
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Vanhanen, Joonas
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Emission of 1.3–10 nm airborne particles from brake materials2017In: Aerosol Science and Technology, ISSN 0278-6826, E-ISSN 1521-7388, Vol. 51, no 1, p. 91-96Article in journal (Refereed)
    Abstract [en]

    Operation of transport vehicle brakes makes a significant contribution to airborne particulate matter in urban areas, which is subject of numerous studies due to the environmental concerns. We investigated the presence and number fractions of 1.3–10 nm airborne particles emitted from a low-metallic car brake material (LM), a non-asbestos organic car brake material (NAO) and a train brake cast iron against a cast iron. Particles were generated by a pin-on-disc machine in a sealed chamber and analyzed using a nano condensation nucleus counter, a CPC, and an FMPS. It was found that 1.3–4.4 nm particles are emitted during the friction. For the pairs with the LM and NAO, 1.3–4.4 nm particles predominate in number at temperatures above 160°C. The emission of the 1.3–4.4 nm particles precedes the emission of above 4.4 nm particles. For the cast iron pair, the number of 1.3–4.4 nm particles is smaller than the number of 4.4–10 nm particles. The findings suggest that brake materials produce a significant number of 1.3–4.4 nm airborne particles, and these particles should not be neglected in environmental and tribological studies.

  • 34.
    Olofsson, Ulf
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Tu, Minghui
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Nosko, Oleksii
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Lyu, Yezhe
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Dizdar, Senad
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.). Höganäs AB, R&D, 263 83 Höganäs, Sweden.
    A pin-on-disc study of airborne wear particle emissions from studded tyre on concrete road contacts2018In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 410-411, p. 165-172Article in journal (Refereed)
    Abstract [en]

    Studded tyres wear surfaces of winter roads, generating inhalable airborne particles. In this study, four concrete road materials and two stud geometries were investigated in terms of wear, road material hardness and airborne particle concentration. The sliding contact between studded tyres and road materials was studied using a pin-on-disc machine in a clean chamber. The results show that the normal load and the stud size have a large influence on the wear and particle emission. It was found that the wear and particle concentration are inversely proportional to the hardness of the aggregate in the road material and proportional to the sliding distance. The particle size distribution has peaks at 0.2 µm, 1 µm and 2 µm. 

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