A method of calculating the components of the coefficient of friction of iron-calcium fluoride materials from experimental data

1974 ◽  
Vol 13 (1) ◽  
pp. 70-72
Author(s):  
K. S. Lyapin ◽  
V. N. Miroshnikov ◽  
N. M. Mikhin ◽  
Yu. F. Shevchuk
Keyword(s):  
Experimental Data ◽  
Coefficient Of Friction ◽  
Calcium Fluoride ◽  
The Coefficient Of Friction

Stress in a flat section band clamp

2003 ◽  
Vol 217 (7) ◽  
pp. 821-830 ◽  
Author(s):  
K Shoghi ◽  
H V Rao ◽  
S M Barrans
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Coefficient Of Friction ◽  
Experimental Work ◽  
Rigid Cylinder ◽  
Initial Stage ◽  
The Coefficient Of Friction ◽  
Flat Section ◽  
Band Material

This paper analyses the stress in a flat section band clamp and validates by experimental data the predictions based on the developed theory. In the experimental work flat section band clamps were positioned around the rigid cylinder and strain and corresponding displacement were measured; the clamp nut was tightened to gradually increasing torque until failure occurred. The error in stress and corresponding displacement predicted by the theory and that obtained by testing was found to be 1–2 per cent for the initial stage where the band is slack on the rigid cylinder, 3–5 per cent where the band makes contact with the cylinder and 5–7 per cent for post-yielding of the band material. This error could mainly be attributed to an uncertainty in the properties for the material and the accuracy of instrumentation. The coefficient of friction between the relevant components and the elastic modulus of the band material are the important properties, which influence the performance of the clamp. In the current experimental work failure occurred in the T-bolt.

scholarly journals Variation of Coefficient of Friction and Friction Head Losses Along a Pipe with Multiple Outlets

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 844 ◽  
Author(s):  
Wissam H. Alawee ◽  
Yousef A. Almolhem ◽  
Badronnisa Yusuf ◽  
Thamer A. Mohammad ◽  
Hayder A. Dhahad
Keyword(s):  
Experimental Data ◽  
Coefficient Of Friction ◽  
Field Studies ◽  
Pipe Length ◽  
G Factor ◽  
Factors Affecting ◽  
Head Losses ◽  
Main Pipe ◽  
Supply Tank ◽  
The Coefficient Of Friction

The flow in a pipe having multiple outlets is considered as an advanced problem in hydraulic engineering; many discrepancies were found in the literature, in addition to the lack of experimental and field studies. The main goal of this study is to simulate the flow in a pipe with multiple outlets in order to examine the existing methodologies for estimation of the friction head losses, and to propose a methodology that is based on experimental data. The main physical model in this study consisted of a water supply tank, a pipe with multiple outlets having a piezometer at each outlet. Different pipe diameters were used in this study, the pipe diameters were 25.4 mm (1 in), 38.1 mm (1.5 in), 50.8 (2 in) and 76.2 mm (3 in). The inlet heads used were 1.7 m and 2.2 m. The data collected from different flow conditions were used to assess the variation in the coefficient of friction and friction head losses along the pipe length. It can be concluded that the spacing between any two successive outlets (S) and area ratio (AR = Area of outlet/Area of the main pipe) are the main factors affecting the friction head losses along the pipe. The ratio of total friction head losses along a pipe with outlets having the same properties (length (L), discharge (Q), diameter (d) and material) to a pipe without outlets and having the same properties is called the G factor. The G factor calculated using selected formulae was overestimated in comparison to the calculated G factor obtained from experimental data. For large values of S/d (spacing between outlets/diameter of main pipe), the difference between coefficient of friction in first segment (f1) and last segment (fn) of the multiple outlet pipe was noted to be minimal.

A Deep Drawing Test for Determining the Punch Coefficient of Friction

1981 ◽  
Vol 103 (2) ◽  
pp. 197-202 ◽  
Author(s):  
S. Rajagopal
Keyword(s):  
Experimental Data ◽  
Coefficient Of Friction ◽  
Deep Drawing ◽  
Stress System ◽  
Drawing Test ◽  
The Coefficient Of Friction ◽  
Cylindrical Region ◽  
Deep Drawing Test ◽  
Lubrication Conditions

A deep drawing test is described for measuring the coefficient of friction between the cylindrical surfaces of the punch and the cup wall. The test is based on an analysis of the stress system in the cylindrical region of contact. Experimental data are presented for steel and aluminum blanks deep-drawn into cups under different lubrication conditions, and the advantages and limitations of the method are discussed.

scholarly journals Scaling theory of rubber sliding friction

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reinhard Hentschke ◽  
Jan Plagge
Keyword(s):  
Experimental Data ◽  
Dimensional Analysis ◽  
Coefficient Of Friction ◽  
Solid Surface ◽  
Viscoelastic Properties ◽  
Sliding Friction ◽  
Simple Expression ◽  
The Other ◽  
Coefficient Of Sliding Friction ◽  
The Coefficient Of Friction

AbstractCurrent theoretical descriptions of rubber or elastomer friction are complex—usually due to extensive mathematical detail describing the topography of the solid surface. In addition, the viscoelastic properties of the elastomer material itself, in particular if the rubber is highly filled, further increase the complexity. On the other hand, experimental coefficients of sliding friction plotted versus sliding speed, temperature or other parameters do not contain much structure, which suggests that a less detailed approach is possible. Here we investigate the coefficient of sliding friction on dry surfaces via scaling and dimensional analysis. We propose that adhesion promotes viscoelastic dissipation by increasing the deformation amplitude at relevant length scales. Finally, a comparatively simple expression for the coefficient of friction is obtained, which allows an intuitive understanding of the underlying physics and fits experimental data for various speeds, temperatures, and pressures.

scholarly journals Scaling Theory of Rubber Sliding Friction

2021 ◽  
Author(s):  
Reinhard Hentschke ◽  
Jan Plagge
Keyword(s):  
Experimental Data ◽  
Dimensional Analysis ◽  
Coefficient Of Friction ◽  
Solid Surface ◽  
Viscoelastic Properties ◽  
Sliding Friction ◽  
Simple Expression ◽  
The Other ◽  
Coefficient Of Sliding Friction ◽  
The Coefficient Of Friction

Abstract Current theoretical descriptions of rubber or elastomer friction are complex-usually due to extensive mathematical detail describing the topography of the solid surface. In addition, the viscoelastic properties of the elastomer material itself, in particular if the rubber is highly filled, further increase the complexity. On the other hand, experimental coefficients of sliding friction plotted versus sliding speed, temperature or other parameters do not contain much structure, which suggests that a less detailed approach is possible. Here we investigate the coefficient of sliding friction on dry surfaces via scaling and dimensional analysis. We propose that adhesion promotes viscoelastic dissipation by increasing deformation amplitude at relevant length scales. Finally, a comparatively simple expression for the coefficient of friction is obtained, which allows an intuitive understanding of the underlying physics and fits experimental data for various speeds, temperatures and pressures.

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
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