Friction Behavior of Clutch-Facing Materials: Friction Characteristics in Low-Velocity Slippage

1972 ◽  
Author(s):  
Tsuchio Bunda ◽  
Atsunobu Fujikawa ◽  
Kazuo Yokoi
Keyword(s):  
Low Velocity ◽  
Friction Behavior ◽  
Friction Characteristics

scholarly journals Cupronickel B10 and YG6 interface friction characteristics tested on a friction device for metal cutting

2019 ◽  
Vol 11 (11) ◽  
pp. 168781401989022
Author(s):  
Chunjian Liu ◽  
Daochun Xu ◽  
Qingqing Li
Keyword(s):  
Friction Coefficient ◽  
Metal Cutting ◽  
Vibration Reduction ◽  
Interface Temperature ◽  
Friction Behavior ◽  
Conduction Model ◽  
Friction Characteristics ◽  
Interface Friction ◽  
Cupronickel B10 ◽  
Solid Liquid

Friction behavior is an important component of the metal-cutting mechanism. A simple and effective friction device that can yield the desired friction characteristics is required. In this article, a friction device with a solid–liquid–gas vibration reduction was proposed to research the interface friction characteristics. The interface friction characteristics of cupronickel B10 and YG6 were obtained through the new friction device, including the friction force, friction temperatures, and friction coefficient. The results show that an experimental solid–liquid–gas vibration reduction is feasible and effective to obtain the interface friction characteristics. The relationship between the friction-interface temperature T2 and the measured-point temperature T1 that was obtained by a heat-conduction model is linear. For cupronickel B10 and YG6, the friction coefficient gradually decreases with an increase in friction speed, and increases initially and then decreases with an increasing load. Based on the effect of friction temperature, friction speed, and load, a friction model for the interface friction characteristics of cupronickel B10 and YG6 was obtained.

scholarly journals Study on friction behavior at the interface between prosthetic socket and liner

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Jingyang Xie ◽  
Xidong Liu ◽  
Jianhua Tang ◽  
Xi Li ◽  
Wei Li
Keyword(s):  
Energy Dissipation ◽  
Coefficient Of Friction ◽  
Temperature Increase ◽  
Friction Behavior ◽  
Friction Characteristics ◽  
Frictional Behavior ◽  
Prosthetic Socket ◽  
The Coefficient Of Friction ◽  
3D Printed ◽  
Frictional Energy Dissipation

Purpose: The friction characteristics at the interface between prosthetic socket and liner have an important influence on the walking function and wearing comfort of amputees. The frictional behavior at the prosthetic socket/liner interface can provide theoretical guidance for the design and selection of prosthetic materials. So it is of great significance to study the friction behavior at prosthetic socket/liner interface. Methods: The surface roughnesses of the prosthetic socket and liner materials were measured by a laser confocal microscope. The frictional behavior at the prosthetic socket/liner interface was studied on a UMT TriboLab Tribometer by simulating the reciprocating sliding contact mode. An infrared camera was used to take thermal images and then calculated the temperature increase at the socket/liner interface. Results: The coefficient of friction of the silicon rubber fabric are significantly smaller than that of the foam liner materials. The frictional energy dissipation at the liner/acrylic socket interface is the smallest, while it is greater for 3D-printed socket materials. Meanwhile, the temperature increase has a positive correlation to the coefficient of friction and frictional energy dissipation. Conclusions: The three kinds of 3D-printed materials with high surface roughness have higher interface coefficient of friction and energy dissipation than acrylic material. The stiffness and energy consumption play an important role in the interface friction characteristics of the prosthetic liner materials. The appropriate coefficient of friction at the surface between prosthetic socket and liner is essential. A type of the reinforcement fiber has influence on the friction behavior of the 3D-printed reinforced nylon.

scholarly journals Friction Behavior of a Wet Clutch Subjected to Accelerated Degradation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Agusmian Partogi Ompusunggu ◽  
Thierry Janssens ◽  
Paul Sas
Keyword(s):  
Sliding Friction ◽  
Test Procedure ◽  
Applied Pressure ◽  
Friction Behavior ◽  
Friction Characteristics ◽  
Test Setup ◽  
Accelerated Degradation ◽  
Pressure Dependency ◽  
Wet Clutch ◽  
Systematic Methodology

This study aims at experimentally investigating the sliding friction characteristics of a wet clutch during its lifetime. More precisely, the objective is to understand how the Stribeck and the frictional lag (i.e, sliding hysteresis) parameters evolve as the clutch degradation progresses. For this purpose, a novel test procedure has been proposed and a set of experiments has been carried out on a fully assembled (commercial) clutch using a modified SAE#2 test setup. Furthermore, a systematic methodology for the Stribeck and the frictional lag parameters identification is developed. Regardless of the applied pressure, it appears that the first three identified Stribeck parameters tend to decrease with the progression of the degradation, while the last parameter tends to increase. In regard to the frictional lag parameter, the trend shows pressure dependency.

scholarly journals Effects of hydraulic oil and lubricant additives on dynamic friction properties under various reciprocating sliding conditions

Friction ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 471-480
Author(s):  
Shinji Kato ◽  
Shinya Sasaki
Keyword(s):  
Shock Absorber ◽  
Dynamic Friction ◽  
Additive Concentration ◽  
Reciprocating Motion ◽  
Friction Behavior ◽  
Friction Characteristics ◽  
Reciprocating Sliding ◽  
Hydraulic Oil ◽  
Additive Formulation ◽  
Zinc Dithiophosphate

Abstract The friction characteristics of a shock absorber are very complex because the reciprocating motion is not always identical. In this study a device was developed and used to analyze the dynamic friction characteristics under various reciprocating sliding conditions to determine the sliding materials and hydraulic oils that improve the shock absorber performance. This study describes the influence of hydraulic oil additive on the fine reciprocating friction characteristics of steel and copper alloy. Hydraulic oils were prepared by blending a paraffinic mineral oil with zinc dithiophosphate (ZnDTP) and polyhydric alcohol ester as additives. The results show that the dynamic frictional characteristics vary mainly depending on the additive concentration. A specific additive formulation induces a unique amplitude-dependent friction behavior. In addition, the influence of different additives on the lubrication mechanism is investigated based on the instrumental analysis of the friction surface.

A Study on the Friction Characteristics of Automotive Composite Brake Pads Using Taguchi Method

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1845-1850 ◽  
Author(s):  
Yun Hae Kim ◽  
Jung Ju Lee ◽  
H. Nisitani
Keyword(s):  
Taguchi Method ◽  
Raw Materials ◽  
Low Cost ◽  
Orthogonal Matrix ◽  
Friction Behavior ◽  
Friction Materials ◽  
Friction Characteristics ◽  
Brake Pads ◽  
Proper Method ◽  
Automotive Brake

It has many variables and factors to design the friction materials for automotive brake pads. The purpose of this study is to develop the proper method to design at low-cost and to find friction characteristics of each raw materials. For the purpose of examining the effect of each major raw materials, we used the Taguchi L 9(34) orthogonal matrix and 1/5 scale dynamo machine for evaluation of the friction characteristics of composite brake pads. Using Taguchi method, it is easy to investigate the influence of each component in complicated composites friction materials. After analyzing the testing results by the Taguchi method, the effect of factors and levels influenced friction behavior was studied.

Electrogalvanized Low Carbon Steel Adhesion Tendency in Friction Processes Under Mixed Lubrication Regime

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
V. Miguel ◽  
J. Coello ◽  
M. C. Manjabacas ◽  
A. Calatayud ◽  
C. Ferrer ◽  
...  
Keyword(s):  
Mineral Oil ◽  
Important Variable ◽  
Mixed Lubrication ◽  
Mathematical Function ◽  
Low Carbon ◽  
Sliding Velocity ◽  
Low Velocity ◽  
Friction Behavior ◽  
Lubrication Regime ◽  
Off Time

Although some authors work at times with large flat dies and evaluate friction under more realistic conditions than usual, pressure is not totally controlled. In any case, cohesive friction does not appear to have been well studied in literature, but pressure and sliding velocity may provide useful information about preventing the cohesive phenomenon in sheet stamping processes. In this work, the coefficient of friction (COF) for DC-05 electrogalvanized steel is experimentally evaluated under lubrication regime by flat face dies. These tests are also considered to reproduce friction conditions in the die-sheet-blankholder system at some stages of the deep drawing process. High pressure condition in a flat friction system can also be considered for studying the friction behavior in the die radius. This work investigates the influence of contact pressure and sliding velocity of the sheet on the COF value. Adhesion tendency during sliding is also evaluated. Sheets were lubricated with a prelube type mineral oil and different lubricant film thicknesses are present on the sheet as a result of the draining off time effect, an aspect that will be evaluated later. Although sliding velocity has almost no influence on the COF value, pressure has an influence that may be expressed by a potential mathematical function. The COF value tends to be constant for high enough pressure values. This behavior may be explained, in part, from the viewpoint of zinc acting as a typical soft metallic lubricant. Sliding velocity is the most important variable from the adhesion phenomenon point of view, which appears more frequently for low velocity values. The draining off time, which some research works consider fixes the initial lubrication conditions in friction tests, has no significant effect when a mineral oil, typically used as a prelube, is selected as a lubricant. The authors found that pressure is the most important variable for the COF value. Velocity is the determining factor for the adhesion phenomenon in friction processes under mixed lubrication.

scholarly journals A molecular dynamics study of the oxidation mechanism, nanostructure evolution, and friction characteristics of ultrathin amorphous carbon films in vacuum and oxygen atmosphere

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shengxi Wang ◽  
Kyriakos Komvopoulos
Keyword(s):  
Amorphous Carbon ◽  
Oxidation Behavior ◽  
Structural Changes ◽  
Oxidation Mechanism ◽  
Md Simulations ◽  
Oxygen Atmosphere ◽  
Experimental Investigations ◽  
Friction Behavior ◽  
Friction Characteristics ◽  
Insight Into

AbstractAmorphous carbon (a-C) films are characterized by extraordinary chemical inertness and unique thermophysical properties that are critical to applications requiring oxidation-resistant, low-friction, and durable overcoats. However, the increasing demands for ultrathin (a few nanometers thick) a-C films in various emerging technologies, such as computer storage devices, microelectronics, microdynamic systems, and photonics, make experimental evaluation of the structural stability and tribomechanical properties at the atomic level cumbersome and expensive. Consequently, the central objective of this study was to develop comprehensive MD models that can provide insight into the oxidation behavior and friction characteristics of ultrathin a-C films exhibiting layered through-thickness structure. MD simulations were performed for a-C films characterized by relatively low and high sp3 contents subjected to energetic oxygen atom bombardment or undergoing normal and sliding contact against each other in vacuum and oxygen atmosphere. The effect of energetic oxygen atoms on the oxidation behavior of a-C films, the dependence of contact deformation and surface attractive forces (adhesion) on surface interference, and the evolution of friction and structural changes (rehybridization) in the former a-C films during sliding are interpreted in the context of simulations performed in vacuum and oxidizing environments. The present study provides insight into the oxidation mechanism and friction behavior of ultrathin a-C films and introduces a computational framework for performing oxidation/tribo-oxidation MD simulations that can guide experimental investigations.

Motions of neutral hydrogen at high latitudes

1967 ◽  
Vol 31 ◽  
pp. 265-278 ◽  
Author(s):  
A. Blaauw ◽  
I. Fejes ◽  
C. R. Tolbert ◽  
A. N. M. Hulsbosch ◽  
E. Raimond
Keyword(s):  
Surface Density ◽  
Velocity Dispersion ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
High Latitudes ◽  
Low Velocity

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

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