Disturbance at a Frictional Interface Caused by a Plane Elastic Pulse

1982 ◽  
Vol 49 (2) ◽  
pp. 361-365 ◽  
Author(s):  
Maria Comninou ◽  
J. R. Barber ◽  
John Dundurs
Keyword(s):  
Closed Form ◽  
Coefficient Of Friction ◽  
Graphical Representation ◽  
Critical Value ◽  
Elastic Solids ◽  
Supersonic Speed ◽  
The Coefficient Of Friction ◽  
Frictional Interface

We consider a plane pulse striking the frictional interface between two elastic solids which are held together by compressive applied tractions and sheared. The pulse causes a disturbance involving separation or slip between the bodies, which propagates along the interface at supersonic speed. The extent of these zones is determined using a convenient graphical representation and the interface tractions are given in closed form. It is found that the results change qualitatively when the coefficient of friction exceeds a critical value.

Hydrodynamic Lubrication of a Porous Slider

1973 ◽  
Vol 15 (3) ◽  
pp. 232-234 ◽  
Author(s):  
J. Prakash ◽  
S. K. Vij
Keyword(s):  
Drag Coefficient ◽  
Closed Form ◽  
Coefficient Of Friction ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Centre Of Pressure ◽  
Slider Bearing ◽  
Frictional Drag ◽  
Pressure Load ◽  
The Coefficient Of Friction

A plane porous slider bearing is analysed and closed form expressions for pressure, load, frictional drag, coefficient of friction and centre of pressure are obtained. The effect of porosity is to decrease the load capacity and friction. However, the coefficient of friction is increased.

Surface Instabilities in Linear Orthotropic Half-Spaces With a Frictional Interface

2011 ◽  
Vol 78 (4) ◽  
Author(s):  
M. A. Agwa ◽  
A. Pinto da Costa
Keyword(s):  
Boundary Conditions ◽  
Plane Strain ◽  
Coefficient Of Friction ◽  
Isotropic Case ◽  
Flutter Instability ◽  
The Coefficient Of Friction ◽  
Frictional Interface ◽  
Rigid Plane ◽  
Plane Oscillations ◽  
Plane Strain Case

This paper studies the friction induced vibrations that may develop in the neighborhood of steady sliding states of elastic orthotropic half-spaces compressed against a rigid plane moving tangentially with a prescribed speed. These vibrations may lead to flutter instability associated to a surfacelike oscillation. The system of dynamic differential equations and boundary conditions that governs the small plane oscillations of the half-space about the steady sliding state is established. The general form of the surface solutions to the plane strain case is given. The way how the coefficient of friction varies with changes in some of the system’s parameters is investigated. It is shown that for certain combinations of material data, low coefficients of friction are found for surface flutter instability (lower than in the isotropic case).

Friction between the teat and teatcup liner during milking

1973 ◽  
Vol 40 (2) ◽  
pp. 191-206 ◽  
Author(s):  
G. A. Mein ◽  
C. C. Thiel ◽  
D. R. Westgarth ◽  
Rosemary J. Fulford
Keyword(s):  
Coefficient Of Friction ◽  
Flow Rate ◽  
Frictional Force ◽  
Large Area ◽  
Elastic Solids ◽  
Milk Flow ◽  
The Coefficient Of Friction ◽  
Frictional Behaviour ◽  
Sinus Pressure

SummaryFour studies are described of the role of friction in maintaining the teatcup stable on the teat. Measurements of the coefficient of friction between teats and pieces of liners, in which most values for the coefficient fell between 0·5 and 1·0, indicated that friction between skin and rubber-like materials was consistent with the general frictional behaviour of elastic solids. Studies during milking showed that the sudden restriction of milk flow that normally occurs near the end of milking is accompanied by a marked fall in the frictional force between the teat and barrel of the open liner. During the period of peak milk flow-rate, the major source of friction maintaining the teatcup stable on the teat is the large area of contact between the teat and liner barrel. The frictional force is derived from the pressure difference across the teat wall which presses the teat against the comparatively rigid liner. Frictional force between the teat and barrel increases after the start of milking because the coefficient of friction rises as one surface gradually moulds to the other. In addition, the total frictional force increases because of the increasing area of contact whenever the teat moves deeper into the liner, until the end of the peak flow-rate period. When this period ends, friction between the teat and open barrel is reduced suddenly because the teat sinus pressure falls. After this stage, the main source of friction appears to be derived from the force between the teat and mouthpiece lip.

Reflection, Refraction, and Absorption of Elastic Waves at a Frictional Interface: P and SV Motion

1981 ◽  
Vol 48 (1) ◽  
pp. 155-160 ◽  
Author(s):  
R. K. Miller ◽  
H. T. Tran
Keyword(s):  
Closed Form ◽  
Approximate Method ◽  
Elastic Waves ◽  
Coulomb Friction ◽  
Broad Class ◽  
Angle Of Incidence ◽  
Elastic Solids ◽  
Time Harmonic ◽  
Frictional Interface ◽  
Refracted Waves

An approximate method of analysis is presented for determining the reflection, refraction, and absorption of obliquely incident planar time-harmonic P or SV waves at a frictional interface between dissimilar elastic solids. The solids are pressed together with sufficient pressure to prevent separation, and the angle of incidence is subcritical. General expressions for the amplitudes and phases of all reflected and refracted waves are developed in closed form for a broad class of models for bonding friction. Specific results are presented for the case of identical elastic solids bonded by Coulomb friction, as an example of application of the general approach.

Experimental Investigation of aluminum doping crumb rubber/epoxy composite in reciprocating motion

2015 ◽  
Vol 3 ◽  
pp. 1
Author(s):  
Goutam Chandra Karar ◽  
Nipu Modak
Keyword(s):  
Experimental Investigation ◽  
Coefficient Of Friction ◽  
Epoxy Composite ◽  
Normal Load ◽  
Crumb Rubber ◽  
The Other ◽  
Reciprocating Motion ◽  
Molding Process ◽  
Friction Tester ◽  
The Coefficient Of Friction

The experimental investigation of reciprocating motion between the aluminum doped crumb rubber /epoxy composite and the steel ball has been carried out under Reciprocating Friction Tester, TR-282 to study the wear and coefficient of frictions using different normal loads (0.4Kg, 0.7Kgand1Kg), differentfrequencies (10Hz, 25Hz and 40Hz).The wear is a function of normal load, reciprocating frequency, reciprocating duration and the composition of the material. The percentage of aluminum presents in the composite changesbut the other components remain the same.The four types of composites are fabricated by compression molding process having 0%, 10%, 20% and 30% Al. The effect of different parameters such as normal load, reciprocating frequency and percentage of aluminum has been studied. It is observed that the wear and coefficient of friction is influenced by the parameters. The tendency of wear goes on decreasing with the increase of normal load and it is minimum for a composite having 10%aluminum at a normal load of 0.7Kg and then goes on increasing at higher loads for all types of composite due to the adhesive nature of the composite. The coefficient of friction goes on decreasing with increasing normal loads due to the formation of thin film as an effect of heat generation with normal load.

scholarly journals Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4217
Author(s):  
Üsame Ali Usca ◽  
Mahir Uzun ◽  
Mustafa Kuntoğlu ◽  
Serhat Şap ◽  
Khaled Giasin ◽  
...  
Keyword(s):  
Weight Loss ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Practical Significance ◽  
Tribological Characteristics ◽  
M 10 ◽  
Wide Range ◽  
The Coefficient Of Friction ◽  
Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

scholarly journals Influence of Beam Power on Young’s Modulus and Friction Coefficient of Ti–Ta Alloys Formed by Electron-Beam Surface Alloying

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1246
Author(s):  
Stefan Valkov ◽  
Dimitar Dechev ◽  
Nikolay Ivanov ◽  
Ruslan Bezdushnyi ◽  
Maria Ormanova ◽  
...  
Keyword(s):  
Electron Beam ◽  
Young’S Modulus ◽  
Coefficient Of Friction ◽  
Young's Modulus ◽  
Beam Power ◽  
Surface Alloying ◽  
Surface Alloys ◽  
X Ray ◽  
The Coefficient Of Friction ◽  
Beam Surface

In this study, we present the results of Young’s modulus and coefficient of friction (COF) of Ti–Ta surface alloys formed by electron-beam surface alloying by a scanning electron beam. Ta films were deposited on the top of Ti substrates, and the specimens were then electron-beam surface alloyed, where the beam power was varied from 750 to 1750 W. The structure of the samples was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Young’s modulus was studied by a nanoindentation test. The coefficient of friction was studied by a micromechanical wear experiment. It was found that at 750 W, the Ta film remained undissolved on the top of the Ti, and no alloyed zone was observed. By an increase in the beam power to 1250 and 1750 W, a distinguished alloyed zone is formed, where it is much thicker in the case of 1750 W. The structure of the obtained surface alloys is in the form of double-phase α’and β. In both surface alloys formed by a beam power of 1250 and 1750 W, respectively, Young’s modulus decreases about two times due to different reasons: in the case of alloying by 1250 W, the observed drop is attributed to the larger amount of the β phase, while at 1750 W is it due to the weaker binding forces between the atoms. The results obtained for the COF show that the formation of the Ti–Ta surface alloy on the top of Ti substrate leads to a decrease in the coefficient of friction, where the effect is more pronounced in the case of the formation of Ti–Ta surface alloys by a beam power of 1250 W.

Reducing the Coefficient of Friction for Fast-Absorbing Gut Suture

2009 ◽  
Vol 35 (12) ◽  
pp. 2004 ◽  
Author(s):  
Jonathan Lee Bingham ◽  
Mariah R. Brown ◽  
Julian Ramsey Mellette
Keyword(s):  
Coefficient Of Friction ◽  
The Coefficient Of Friction

First Paper: Effect of Under-Lip Temperature on the Lubrication of Rotary Shaft Garter Spring Seals

1966 ◽  
Vol 181 (1) ◽  
pp. 185-190 ◽  
Author(s):  
D. J. Lines ◽  
J. M. Lawrie ◽  
J. P. O'Donoghue
Keyword(s):  
Coefficient Of Friction ◽  
Operating Temperature ◽  
Lubrication Theory ◽  
Fluid Film ◽  
Hydrodynamic Parameter ◽  
Accurate Knowledge ◽  
The Coefficient Of Friction ◽  
Surface Thermocouple ◽  
Sealing Mechanism ◽  
Film Lubrication

Although rotary shaft garter spring seals are widely used throughout industry, very little is known about the sealing mechanism of the lip-shaft interface. It is now generally accepted that some sort of fluid film separates the lip and the shaft. Previous workers have also postulated a relationship between the coefficient of friction and a non-dimensional hydrodynamic parameter, as in standard lubrication theory. This present paper clarifies this relationship, and shows that seals can also operate over the mixed friction, as well as the full film lubrication region. The results were obtained by accurate knowledge of the operating temperature under the sealing lip. Two types of surface thermocouple were developed to do this and these are described in full.

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