scholarly journals Experimental Estimation of Wear Resistance of Polyamide Composites, Reinforced By Carbon and Glass Fibres Used in Metal-Polymer Gearings

2020 ◽  
Vol 14 (4) ◽  
pp. 206-210
Author(s):  
Myron Chernets ◽  
Myroslav Kindrachuk ◽  
Anatolii Kornienko ◽  
Alina Yurchuk
Keyword(s):  
Mathematical Model ◽  
Wear Resistance ◽  
Sliding Friction ◽  
Characteristic Functions ◽  
Model Parameters ◽  
Linear Wear ◽  
Wear Model ◽  
Friction Forces ◽  
Material Wear ◽  
Metal Polymer

Abstract The method of model triboexperimental studies to determine the basic mathematical model parameters of materials wear resistance at sliding friction is considered. The quantitative relative experimental characteristics of wear resistance of glass fibre and carbon fibre reinforced polyamide used in metal-polymer gear couple have been determined. Wear resistance functions of these functional polymeric composites have been established as the basic ones in the tribokinetic mathematical model of material wear for sliding friction conditions. Also, according to the conducted researches, wear resistance diagrams were constructed. They may be used as graphical indicators of wear resistance in the required range of specific friction forces. The dependences that connect the characteristic functions of wear resistance of these materials (obtained by the developed mathematical tribokinetic wear model) with linear wear and gearing service life are presented.

scholarly journals A NUMERICAL EXPERIMENT ON MATHEMATICAL MODEL OF FORECASTING THE RESULTS OF KNOWLEDGE TESTING

2011 ◽  
Vol 17 (1) ◽  
pp. 42-61 ◽  
Author(s):  
Natalja Kosareva ◽  
Aleksandras Krylovas
Keyword(s):  
Mathematical Model ◽  
Characteristic Function ◽  
Goodness Of Fit ◽  
Characteristic Functions ◽  
Model Parameters ◽  
Information Function ◽  
Test Information ◽  
Parametric Functions ◽  
Office Rooms ◽  
Test Information Function

In this paper the new approach to the forecasting the results of knowledge testing, proposed earlier by authors, is extended with four classes of parametric functions, the best fitting one from which is selected to approximate item characteristic function. Mathematical model is visualized by two numerical experiments. The first experiment was performed with the purpose to show the procedure of selecting the most appropriate item characteristic function and adjusting the parameters of the model. Goodness-of-fit statistic for detecting misfit of the selected model is calculated. In the second experiment a test of 10 items is constructed for the population with latent ability having normal distribution. Probability distribution of total test result and test information function are calculated when item characteristic functions are selected from four classes of parametric functions. In the next step it is shown how test information function value could be increased by adjusting parameters of item characteristic functions to the observed population. This model could be used not only for knowledge testing but also when solving diagnostic tasks in various fields of human activities. Other advantage of this method is the reduction of resources of testing process by more precise adjustment of the model parameters and decreasing the standard error of measurement of the estimated examinee ability. In the presented example the methodology is applied for solving the problem of microclimate evaluation in office rooms.

STUDY OF WEAR RESISTANCE OF REINFORCED POLYAMIDE COMPOSITES FOR METAL-POLYMER GEAR DRIVES

Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 19-23
Author(s):  
Myron CHERNETS ◽  
Serge SHIL'KO ◽  
Mikhail PASHECHKO
Keyword(s):  
Wear Resistance ◽  
Sliding Friction ◽  
Gear Wheel ◽  
Gear Ratio ◽  
Carbon Fibres ◽  
Gear Drive ◽  
Glass Fibres ◽  
Gear Drives ◽  
Contact Pressures ◽  
Metal Polymer

An experimental study of the wear resistance of two dispersion-filled composite materials based on polyamide used in metal-polymer gear drives with a 30% volume content of short glass or carbon fibres was performed according to the technique proposed by the authors. As a result of tribotests in the “pin-disk” scheme, the mass wear of these composites was determined under dry friction conditions for steel 45 at room temperature in the range of contact pressures of 10–40 MPa, as well as the kinetics of the coefficient of sliding friction and the contact temperature of the tribosystem elements. It was established that polyamide strengthened by carbon fibres has almost four times higher wear resistance in comparison with a polyamide filled with glass fibres. The wear resistance characteristics that are the basic parameters of the tribokinetic wear model are calculated, using the durability of the straight spur metal-polymer gear drive on the basis of the original calculation method. It was established that gear drive durability with a pinion or a wheel reinforced with carbon fibres is more than eight times the durability of gear drive with gear wheels from polyamide filled with glass fibres. The gear drive durability with the steel pinion and the composite gear wheel increases in proportion to the gear ratio as compared to the gear drive with the composite pinion and the steel wheel. The change in the maximum contact pressures in the mesh interval was calculated.

scholarly journals Prediction the wear of sliding bearings

2018 ◽  
Vol 7 (2.23) ◽  
pp. 4 ◽  
Author(s):  
Dykha Aleksandr ◽  
Marchenko Dmitry
Keyword(s):  
Wear Resistance ◽  
Experimental Method ◽  
Wear Test ◽  
Design Stage ◽  
Linear Wear ◽  
Sliding Velocity ◽  
Operational Parameters ◽  
Wear Model ◽  
Sliding Bearings ◽  
Sliding Bearing

The problem of developing a calculation-experimental method for calculating wear of a sliding bearing based on a two-factor wear model (contact pressure - sliding velocity) with identification of wear resistance parameters was considered. On the basis of the proposed wear model, the wear-contact problem for a cylindrical sliding bearing was solved. The equation of equilibrium for medium pressures and the approximating function of linear wear from the arc of contact between the shaft and the bushing were used as the determining equations. To identify parameters of wear resistance in the wear model, a calculation-experimental method for determining calculated dependences of wear resistance parameters was developed on the basis of the wear test by the «cone – three balls» scheme. The results of wear tests of bronze conical specimens with a variable wear spot and two values of sliding velocity were taken as a base. The obtained results were recommended for predicting wear of sliding bearings at the design stage and optimizing their design and operational parameters.  

KAISER ALUMINUM ALLOY 4026

Alloy Digest ◽  
2003 ◽  
Vol 52 (10) ◽  
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Physical Properties ◽  
Tensile Properties ◽  
Sliding Friction ◽  
High Strength ◽  
Heat Treating ◽  
Kaiser Aluminum ◽  
Friction Resistance

Abstract Kaiser Aluminum alloy 4026 has high strength and good wear resistance, as well as galling resistance. It was developed for sliding friction resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on heat treating. Filing Code: AL-385. Producer or source: Tennalum, A Division of Kaiser Aluminum.

Multiple Reflow Influence over the FeCoCrAlTiCuNiMo Coating Obtained by Plasma Metallization on its Wear Resistance under Dry Friction

2021 ◽  
Vol 410 ◽  
pp. 475-481
Author(s):  
Anvar M. Kadyrmetov ◽  
Dmitri A. Popov ◽  
Yevgeny V. Snyatkov
Keyword(s):  
Wear Resistance ◽  
Dry Friction ◽  
Sliding Friction ◽  
Plasma Jet ◽  
Dry Sliding ◽  
Research Results ◽  
Open Atmosphere ◽  
Multicomponent Coating ◽  
Dry Sliding Friction

The article presents the research results of the plasma jet multiple reflow effect over the multicomponent coating FeCoCrAlTiCuNiMo, obtained by plasma metallization in an open atmosphere, on its wear resistance under dry sliding friction. The research results indirectly confirm the influence of the coating entropy over the wear resistance increasing along of the reflow number growth.

scholarly journals The identification of a device based on a Peltier element by the least squares method

2020 ◽  
pp. 17-27
Author(s):  
Vladimir Grinkevich ◽  
Keyword(s):  
Mathematical Model ◽  
Least Squares ◽  
Least Squares Method ◽  
Control Object ◽  
Object Identification ◽  
Model Parameters ◽  
Peltier Element ◽  
Transport Delay ◽  
Non Linear ◽  
The Mathematical Model

The evaluation of the mathematical model parameters of a non-linear object with a transport delay is considered in this paper. A temperature controlled stage based on a Peltier element is an identification object in the paper. Several input signal implementations are applied to the input of the identification object. The least squares method is applied for the calculation of the non-linear differential equitation parameters which describe the identification object. The least squares method is used due to its simplicity and the possibility of identification non-linear objects. The parameters values obtained in the process of identification are provided. The plots of temperature changes in the temperature control system with a controller designed based on the mathematical model of the control object obtained as a result of identification are shown. It is found that the mathematical model obtained in the process of identification may be applied to design controllers for non-linear systems, in particular for a temperature stage based on a Peltier element, and for self-tuning controllers. However, the least square method proposed in the paper cannot estimate the transport delay time. Therefore it is required to evaluate the time delay by temperature transient processes. Dynamic object identification is applied when it is required to obtain a mathematical model structure and evaluate the parameters by an input and output control object signal. Also, identification is applied for auto tuning of controllers. A mathematical model of a control object is required to design the controller which is used to provide the required accuracy and stability of control systems. Peltier elements are applied to design low-power and small- size temperature stage . Hot benches based on a Peltier element can provide the desired temperature above and below ambient temperature.

scholarly journals Selection of the chemical composition of steels and their thermal hardening mode using a computer program

2021 ◽  
pp. 59-65
Author(s):  
D. M. Berdiev ◽  
M. A. Uмаrоvа ◽  
A. A. Yusupov
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Computer Program ◽  
Sliding Friction ◽  
Thermal Hardening ◽  
Abrasive Particles ◽  
Density Of Dislocations ◽  
Heat Treated ◽  
Final Tempering ◽  
Selection Of

The relationships between the parameters of the structure of heat‑treated steels and their abrasive wear resistance are established. At all temperatures of the final tempering of hardened steel, there is a direct relationship between its structure parameters (the number of elements in a solid solution, the density of dislocations, the size of cementite particles and the intercementite distance) and wear resistance when sliding friction against loose abrasive particles. A computer program has been developed to select the chemical composition of the steel grade and methods of thermal hardening in order to ensure the required wear resistance.

scholarly journals Hydrogen wear resistance under the metal-polymer friction pairs operation

2018 ◽  
Vol 91 (3) ◽  
pp. 88-92
Author(s):  
Olexandr Burya ◽  
Valentina Dubkova ◽  
Igor Pachkovski ◽  
Timothy Rybak ◽  
Iryna Rula
Keyword(s):  
Wear Resistance ◽  
Polymer Friction ◽  
Metal Polymer

scholarly journals A MATHEMATICAL MODEL OF NONSTATIONARY MOTION OF A VISCOELASTIC FLUID IN ROLLER BEARINGS

2019 ◽  
Vol 81 (4) ◽  
pp. 501-512
Author(s):  
I.A. Zhurba Eremeeva ◽  
D. Scerrato ◽  
C. Cardillo ◽  
A. Tran
Keyword(s):  
Mathematical Model ◽  
Viscoelastic Fluid ◽  
Viscoelastic Properties ◽  
Fluid Model ◽  
Maxwell Fluid ◽  
Initial Boundary ◽  
Deborah Number ◽  
Nonstationary Motion ◽  
Friction Forces ◽  
Roller Bearings

Nowadays, the emergence of new lubricants requires an enhancement of the rheological models and methods used for solution of corresponding initial boundary-value problems. In particular, models that take into account viscoelastic properties are of great interest. In the present paper we consider the mathematical model of nonstationary motion of a viscoelastic fluid in roller bearings. We used the Maxwell fluid model for the modeling of fluid properties. The viscoelastic properties are exhibited by many lubricants that use polymer additives. In addition, viscoelastic properties can be essential at high fluid speeds. Also, viscoelastic properties can be significant in the case of thin gaps. Maxwell's model is one of the most common models of viscoelastic materials. It combines the relative simplicity of constitutive equations with the ability to describe a stress relaxation. In addition, viscoelastic fluids also allow us to describe some effects that are missing in the case of viscous fluid. An example it is worth to mention the Weissenberg effect and a number of others. In particular, such effects can be used to increase the efficiency of the film carrier in the sliding bearings. Here we introduced characteristic assumptions on the form of the flow, allowing to significantly simplify the solution of the problem. We consider so-called self-similar solutions, which allows us to get a solution in an analytical form. As a result these assumptions, the formulae for pressure and friction forces are derived. Their dependency on time and Deborah number is analyzed. The limiting values of the flow characteristics were obtained. The latter can be used for steady state of the flow regime. Differences from the case of Newtonian fluid are discussed. It is shown that viscoelastic properties are most evident at the initial stage of flow, when the effects of non-stationarity are most important.

Improvement of Wear Resistance of UHMWPE by Adding Solid Lubricating Fillers

2016 ◽  
Vol 712 ◽  
pp. 155-160 ◽  
Author(s):  
Sergey V. Panin ◽  
Lyudmila А. Kornienko ◽  
Vladislav O. Alexenko ◽  
Larisa R. Ivanova
Keyword(s):  
Wear Resistance ◽  
Dry Friction ◽  
Sliding Friction ◽  
Weight Fraction ◽  
Dry Sliding ◽  
Polyethylene Matrix ◽  
Permolecular Structure ◽  
Uhmwpe Composites ◽  
Ultra High Molecular Weight ◽  
Tribotechnical Characteristics

For estimating effectiveness of adding solid fillers for composites with ultra-high molecular weight polyethylene matrix tribotechnical characteristics of UHMWPE mixture with graphite, molybdenum disulfide and polytetrafluoroethylene were investigated under dry friction, boundary lubrication and abrasion. The optimum filler weight fraction was determined in terms of increasing wear resistance. Permolecular structure and surface topography of wear tracks for UHMWPE composites with different weight fraction of the fillers was studied. The mechanisms of wear of polymeric composites “UHMWPE-graphite”, “UHMWPE-PTFE” and “UHMWPE-MoS2” under dry sliding friction and abrasive wear are discussed.

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