Thermal Correlation Assessment of the Resource of Interfaces with Solid Lubricating Coatings Based On Mos2 Applied by Magnetron and Other Methods, for Vacuum Conditions

2021 ◽  
pp. 72-80
Author(s):  
P.N. Khopin ◽  
V.V. Grib
Keyword(s):  
High Frequency ◽  
Friction Pair ◽  
Surface Friction ◽  
Friction Temperature ◽  
Thermal Correlation

The analysis of tribotechnical parameters of interfaces with solid lubricating coatings based on MoS2, applied by different methods, was carried out according to the results of tests in vacuum. The surface friction temperature is calculated on the basis of the performed assessment of the load-speed characteristics of these interfaces. Based on the results of tribovacuum tests, the thermocorrelation dependence of the resource of a friction pair with solid lubricating coatings MoS2, applied by vacuum (magnetron and high-frequency) and suspension methods, on the surface friction temperature of the interface was determined. On the basis of this dependence, a method for calculating the resource of the studied tribointerfaces is proposed.

Investigation of Friction Temperature in Railway Disc Brake

2012 ◽  
Vol 479-481 ◽  
pp. 202-206
Author(s):  
Wan Hua Nong ◽  
Fei Gao ◽  
Rong Fu ◽  
Xiao Ming Han
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Friction Pair ◽  
Brake Disc ◽  
Finite Element Software ◽  
Disc Surface ◽  
Friction Temperature ◽  
Steel Disc ◽  
Braking Force ◽  
Braking Process

The distribution of temperature on the rubbing surface is an important factor influencing the lifetime of a brake disc. With a copper-base sintered brake pad and a forge steel disc, up-to-brake experiments have been conducted on a full-scale test bench at a highest speed of 200 Km/h and a maximum braking force of 22.5 KN. The temperature distributions on brake disc surface have been acquired by an infrared thermal camera, and the contact pressure on the contact surface of the friction pair has been calculated by the finite element software ABAQUS. The results show that the area and thermal gradient of the hot bands increase with the increase of braking speed and braking force. The hot bands occur in priority at the radial location of r=200 mm and r=300 mm, and move radially in the braking process. The finite element modelling calculation indicates that the distribution of the contact pressure on the disc surface in radial direction is in a "U"-shape. The maximum contact pressure occur at the radial locations of r=200 mm and r=300 mm, and the minimum contact pressure occur in the vicinity of the mean radius of the disc. The conformity of contact pressure distributions with the practical temperature evolutions indicates that the non-uniform distribution of the contact pressure is the factor resulting in the appearance of hot bands on the disc surface.

PROBLEMS OF TRIBOLOGIC CHARACTERIZATION OF SHOE – WALKING SURFACE FRICTION PAIRS

Tribologia ◽  
2018 ◽  
Vol 282 (6) ◽  
pp. 125-129 ◽  
Author(s):  
Jacek PRZEPIÓRKA ◽  
Marian SZCZEREK
Keyword(s):  
Friction And Wear ◽  
Friction Pair ◽  
Surface Friction ◽  
The Other ◽  
Tribological Characteristics ◽  
Footwear Industry ◽  
Energetic Condition ◽  
Basic Parameters

Tribological characteristics of shoe sole in a friction pair with the walking surface are important parameters due to the safety of shoe exploitation and time of its durability. The footwear industry methods of analysing friction coefficient are obsolete, and, on the other hand, modern tribological equipment that allows credible results requires long data processing. The authors suggest using a previously developed formula that binds tribological characteristics with energetic condition of the walking surface. By doing so, this formula evaluates the force of friction and wear of shoe – walking surface pair. It may shorten the time needed to evaluate the basic parameters of shoe exploitation in variable conditions of their utilization and, thus, contribute to the formulation of material resolutions aiming to improve the quality of shoe usage while reducing the costs of performing required examinations.

Coupling Analysis of Frictional Heat under Control of Disc Brake Anti-Skid Brake System

2011 ◽  
Vol 199-200 ◽  
pp. 721-728
Author(s):  
Yi Bing Zhang ◽  
Ying Ying Zhang
Keyword(s):  
Thermal Stress ◽  
Friction Pair ◽  
Brake System ◽  
Frictional Heat ◽  
Brake Disc ◽  
Analysis Model ◽  
Element Analysis ◽  
Study Results ◽  
Friction Temperature ◽  
Braking Force

The nonlinearity of material properties at different temperatures and the manner of braking force applying on a brake system are two key factors to affect the coupling of temperature and thermal stress. Considering these two factors, a finite element analysis model of automobile brake disc and pad is established. By using the model, the dynamic frictional heat and thermal stress of braking friction pair could be simulated and the coupling characters of temperature and thermal stress on friction surfaces could be studied, where the braking force is constant or controlled by an anti-skid brake system(ABS). The study results shown that the friction temperature of brake disk rises in periodic and fluctuant tendency. The fluctuant increase of temperature will influence the character of braking. The increase of friction temperature between a brake disc and pad can decrease under the control of ABS, so the effect of thermo-mechanical coupling could be reduced.

scholarly journals Effect of Micro-Textured Surfaces and Sliding Speed on the Lubrication Mechanism and Friction-Wear Characteristics of CF/PEEK Rubbing against 316L Stainless Steel under Seawater Lubrication

2021 ◽  
Vol 11 (21) ◽  
pp. 9915
Author(s):  
Yingna Liang ◽  
Jianxin Gao ◽  
Dianrong Gao ◽  
Yanan Sun ◽  
Zongyi Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
316L Stainless Steel ◽  
Adhesive Wear ◽  
Friction Pair ◽  
Surface Friction ◽  
Contact Temperature ◽  
Oxidative Wear ◽  
Lubrication Mechanism ◽  
Sliding Speed ◽  
Wear Characteristics

In this work, the lubrication mechanism and friction-wear characteristics of the friction pair between carbon-fiber-reinforced polyether ether ketone (CF/PPEK) and 316L stainless steel with a micro-hemispherical pit textured surface at different sliding speeds under seawater lubrication were studied through numerical simulation and experimental investigation. The study results indicate that the seawater moves following the sliding direction of the upper specimen, forms a vortex ring flow in the hemispherical pit of the bottom specimen, uses the convergent gap to generate a hydrodynamic effect, produces the bearing capacity, and realizes fluid lubrication. The hemispherical pit diminishes the abrasive wear during the friction process by storing the wear debris, and the main wear forms of the hemispherical-pit surface friction pair are oxidative wear and adhesive wear. The friction coefficient of the hemispherical-pit surface friction pair is 0.018–0.027, the specimen contact temperature is 40.2–55.1 °C, and it is always in the hydrodynamic lubrication state in a rotation speed ranging from 1000 r/min to 1750 r/min. As the sliding speed increases, the specimen contact temperature climbs, and the oxidation reaction gradually becomes full. Oxidative wear and adhesive wear alternately play a dominant role in the friction, and the wear rate first decreases and then increases sharply.

Fault Mechanism Analysis and Characteristic Extraction for Multi-Disc Clutch

2014 ◽  
Vol 526 ◽  
pp. 155-163
Author(s):  
Man Chen ◽  
He Yan Li ◽  
Biao Ma
Keyword(s):  
High Frequency ◽  
Initial Phase ◽  
Friction Pair ◽  
Vibration Signal ◽  
Coupling Model ◽  
Dynamics Simulation ◽  
Mechanism Analysis ◽  
The Difference ◽  
Vibration Signal Analysis ◽  
The Impact

The thermo-elastic coupling model of clutch friction pair is established by the thermoelastic instability theory to acquire the basic process of friction disc warp due to hot agglomeration; according to this process, thought of reflecting initial phase clutch fault by observing the partial deformation generated by hot spots is proposed in this paper. And based on this thought, the multi-disc clutch dynamics simulation model is established to acquire the dynamic characteristics existing on the friction pair when tiny deformation happens; according to vibration characteristics of this characteristics and the feature that the interference noise of the high frequency section of the transmission system is comparatively light, and based on the analysis on the difference of frequency spectrum of the high frequency section before and after shifting gears, a new kind of initial phase multi-disc clutch fault diagnosing method based on vibration signal analysis is proposed. The test results further prove that, this method can be used to extract the impact vibration generated by tiny deformation happened on the friction pair, and is hopeful to be used in the practical engineering of initial phase multi-disc clutch fault diagnosing.

Surface Friction Guiding for Reduced High-Frequency Lateral Vibration of Moving Media

2006 ◽  
Vol 129 (3) ◽  
pp. 371-379 ◽  
Author(s):  
V. Kartik ◽  
J. A. Wickert
Keyword(s):  
High Frequency ◽  
Surface Friction ◽  
Lateral Position ◽  
Lateral Vibration ◽  
Moving Medium ◽  
Equivalent Viscous Damping ◽  
Equivalent Damping ◽  
High Frequency Response ◽  
Pressure Transport ◽  
Mode Transitions

The free and forced vibration of a moving medium is examined in an application where distributed friction guiding is used to control lateral position passively. Subambient pressure features formed in the guides intentionally modify the naturally occurring self-pressurized air bearing and increase the contact force between the medium and the guide’s surface. These features increase friction to a level beyond that achievable based on the nominal wrap pressure. The moving medium is modeled as a beam that is transported over frictional regions and subjected to prescribed boundary disturbances arising from runout of a supply or take-up roll. For axial transport at a speed that is high compared to the velocity of lateral vibration, Coulomb friction between the guides and the moving medium can be well approximated by a derived expression for equivalent viscous damping. The equation of motion is developed for the cases of a single cylindrical guide and of a multiplicity of guides having arbitrary placement. The level of equivalent damping for each mode decreases with transport speed, and critical speeds exist where each vibration mode transitions between the overdamped and underdamped regimes. Parameter studies in the contact pressure, transport speed, and guide geometry identify preferred design configurations for maximizing dissipation in particular modes and for attenuating high-frequency response.

Investigation of Wear Behaviour of Sewn Assemblies of Viscose Linings with Different Treatment

1970 ◽  
Vol 17 (2) ◽  
pp. 155-159 ◽  
Author(s):  
Dainora BAČKAUSKAITĖ ◽  
Virginija DAUKANTIENĖ
Keyword(s):  
Friction Pair ◽  
Surface Friction ◽  
Woven Fabrics ◽  
The Other ◽  
Wear Behaviour ◽  
Surface Appearance ◽  
Different Types ◽  
Textile Finishing ◽  
Friction Parameters ◽  
Fabric Surface

Different types of chemical treatment of textile are widely applied in advanced textile. Finishing of textile can provide additional functional properties for products or/and to improve the appearance of final product as well as to improve their mechanical properties. In this research the influence of the industrial treatment of viscose linings on the parameters of fabric surface friction, on fabric surface appearance as well as on the slippage resistance of yarns at a seam was investigated. Raw, dyed, dyed and softened, dyed and non-slip finished plain weaved linings were investigated. The slippage resistance of yarns at a seam in woven fabrics was evaluated according to standard EN ISO 13936-1:2004. The friction was investigated according to the standard DIN 53375 in a fabric-fabric friction pair. Surface of raw, dyed, dyed and softened viscose lining was investigated using SEM. The obtained results have shown that the friction parameters as well as the parameters of seam slippage resistance of dyed or dyed and softened fabrics were higher than the ones of raw fabric. The highest differences in those parameters were obtained for lining that was dyed and treated with non-slip finishing. That type of finishing influenced the break of lining yarns without typical to the other investigated linings slipping near a stitching line.http://dx.doi.org/10.5755/j01.ms.17.2.485

scholarly journals The Dependence of Aftereffects and Contact of Rough Surfaces Composite – Metal from Orientation Factors of Dispersed Phase of Polymer Matrix

2016 ◽  
Vol 17 (2) ◽  
pp. 294-305
Author(s):  
H.O. Sirenko ◽  
L.M. Soltys
Keyword(s):  
Fiber Orientation ◽  
Friction Surface ◽  
Carbon Materials ◽  
Friction Pair ◽  
Surface Friction ◽  
Sliding Direction ◽  
Orientation Effects ◽  
Carbon Plastics ◽  
Fibrous Carbon ◽  
Surface Changes

Results of researches of influence orientation effects on the friction properties of carbon-plastics and wear mechanism of unidirectional carbon-plastics have been brought in a work. The optimal structure of carbon-plastics and fiber orientation layers in it relative to the surface friction and sliding direction have been provided. The influence of schemes reinforcing by fibrous carbon materials of polymer composites and schemes contacting of samples composites with the surface of metal counterface on the intensity of wear of friction pair and on the changing of microroughness parameters of metal surface have been researched. It has been shown that the topography of metal counterface surface changes in friction carbon plastics with oriented fibers, but the allocation of heights and curvatures of microroughness peaks of friction surface far removed from the Gaussian allocation and close to Rayleigh allocation.

Surface Friction Guiding for Reduced High Frequency Lateral Vibration of Moving Media

2006 ◽  
Author(s):  
V. Kartik ◽  
J. A. Wickert
Keyword(s):  
High Frequency ◽  
Ambient Pressure ◽  
Surface Friction ◽  
Lateral Position ◽  
Vibration Velocity ◽  
Moving Medium ◽  
Equivalent Viscous Damping ◽  
Equivalent Damping ◽  
High Frequency Response ◽  
Mode Transitions

The free and forced vibration of a moving medium is examined in an application where distributed friction guiding is used to control lateral position passively. Sub-ambient pressure features formed in the guides intentionally modify the naturally occurring self-pressurized air bearing and increase the contact force between the medium and the guide's surface. These features increase friction to a level beyond that achievable based on the nominal wrap pressure. The moving medium is modeled as a beam that is transported over frictional regions and that is subjected to prescribed boundary disturbances arising from runout of a cartridge or pack. For axial transport at a speed that is high compared to the vibration velocity, Coulomb friction between the guides and the moving medium can be well-approximated by a derived expression for equivalent viscous damping. The equation of motion is developed for the cases of a single cylindrical guide, and of a multiplicity of guides having arbitrary placement. The level of equivalent damping for each mode decreases with transport speed, and critical speeds exist where each vibration mode transitions between the overdamped and underdamped regimes. Parameter studies in the contact pressure, transport speed, and guide geometry identify preferred design configurations for maximizing dissipation in particular modes and for attenuating high frequency response.

Experimental Research of Tire Elastomer-Surface Tribological Properties

2014 ◽  
Author(s):  
Andrei A. Kupreyanov ◽  
Mikhail V. Morozov ◽  
Boris N. Belousov ◽  
Tatiana I. Ksenevich ◽  
Vladimir V. Vantsevich
Keyword(s):  
Tribological Properties ◽  
Friction Pair ◽  
Thermodynamic Characteristics ◽  
Surface Friction ◽  
Normal Pressure ◽  
Test Results ◽  
Test Rig ◽  
Friction Process ◽  
Factor Ii ◽  
Experimental Findings

This paper presents a new experimental test rig and experimental findings on tire elastomer-surface friction characteristics that are necessary for modeling tire thermodynamic characteristics and then tire characteristics, including the μ-curve in the driving and braking modes of operation. Unlike common approaches, the paper offers experimental procedures and test results on both steady and non-steady friction process by introducing (i) velocity factor, (ii) normal pressure distribution, and (iii) a temperature factor in the elastomer-surface contact. The group of (i), (ii), and (iii)-listed factors, taken together, represents the key elements by means of which tribological properties of the tire-road interaction, i.e., an elastomer-surface friction pair, impact the μ-curve.

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