scholarly journals Estimating the Impact of Texture Depth on the Roughness of Cement Concrete Airfield Pavements

2019 ◽  
Vol 49 (2) ◽  
pp. 341-362 ◽  
Author(s):  
Mariusz Wesołowski ◽  
Krzysztof Blacha
Keyword(s):  
Coefficient Of Friction ◽  
Contact Surface ◽  
Field Tests ◽  
Surface Friction ◽  
Skid Resistance ◽  
Cement Concrete ◽  
Friction Characteristics ◽  
The Coefficient Of Friction ◽  
The Impact

Abstract Appropriate skid resistance properties of airfield pavements are extremely important in terms of the safety of air operations. Their evaluation is not limited to the measurements of the coefficient of friction, which determines the roughness of a pavement, but also involves measuring the depth of the pavement texture (micro- and macrotexture), which is a component of the tire-pavement contact surface friction characteristics. It should be stressed that the current aviation documents do not contain a strict interconnection between the texture depth parameter and airfield pavement coefficient of friction criteria. Based on the result population gathered in the course of the field tests, the authors plan to determine the impact of texture on the roughness of airfield pavements.

scholarly journals Evaluation of airfield pavement micro and macrotexture in the light of skid resistance (friction coefficient) measurements

2019 ◽  
Vol 262 ◽  
pp. 05017 ◽  
Author(s):  
Mariusz Wesołowski ◽  
Krzysztof Blacha
Keyword(s):  
Friction Coefficient ◽  
Contact Surface ◽  
Asphalt Concrete ◽  
Field Tests ◽  
Skid Resistance ◽  
Cement Concrete ◽  
Concrete Technology ◽  
Significant Component ◽  
Applied Study ◽  
The Subject

Appropriate skid resistance properties of airfield pavements are extremely important in terms of the safety of air operations. When discussing skid resistance properties of airfield pavements, we should not limit the subject only to the friction coefficient, which determines the state of its roughness. Attention should be paid to the fact that a significant component of friction characteristics of a tyre/pavement contact surface is the pavement texture (microtexture and macrotexture). The authors of the article presented the currently applied study methods in the scope of evaluating the texture of road and airfield pavements. The paper also presents sample results of field tests, which were conducted on new airfield pavements (executed in the cement concrete and asphalt concrete technology), as well as their short analysis in relation to evaluating the skid resistance properties (friction coefficient). Particular attention was paid to the current requirements in this scope, imposed on airfield pavements and the assessment criteria of the obtained results. Moreover, the paper also presents a direction of further works conducted by the authors with a broader team, in the scope of developing the study method for the assessment of airfield pavement texture.

Paper 16: Friction in Wet Clutches

1967 ◽  
Vol 182 (14) ◽  
pp. 132-138 ◽  
Author(s):  
E. M. Evans ◽  
J. Whittle
Keyword(s):  
Coefficient Of Friction ◽  
Power Transmission ◽  
Sliding Speed ◽  
Friction Materials ◽  
Friction Characteristics ◽  
Sliding Surfaces ◽  
Base Oils ◽  
Wet Friction ◽  
Friction Clutch ◽  
The Coefficient Of Friction

This paper is intended to demonstrate that designers of wet clutches for power transmission can obtain the optimum friction characteristics for specific applications by considering the interaction between friction materials and lubricants. A friction clutch plate rig is described and the friction results obtained are presented. It is shown that a wide variation of coefficients of friction and frictional characteristics in wet friction clutches can be obtained by changing the oils and friction materials. In particular the coefficient of friction is dependent upon (1) the oil, (2) the materials of the sliding surfaces, (3) sliding speed, and (4) temperature. It is also shown that the coefficient of friction is affected by ( a) refining treatment given to the oil, ( b) different base oils, and ( c) additives.

Study of the micro/nano-texture design to improve the friction properties of DLC thin films

2021 ◽  
pp. 2140027
Author(s):  
Young Woo Kwon ◽  
Mun Ki Bae ◽  
Ri-Ichi Murakami ◽  
Tae Hwan Jang ◽  
Tae Gyu Kim
Keyword(s):  
Thin Film ◽  
Coefficient Of Friction ◽  
Surface Friction ◽  
Low Friction ◽  
Frictional Wear ◽  
The Coefficient Of Friction ◽  
Surface Contact Area ◽  
Photolithography Process ◽  
Texture Design ◽  
Pattern Width

In this study, a DLC pattern was fabricated through a photolithography process that constitutes a part of the semiconductor process, to investigate the frictional wear characteristics. The photolithography was used to produce negative patterns with a pattern width of 10 [Formula: see text]m or 20 [Formula: see text]m and a pattern depth of 500 nm on the DLC surface. The change in the coefficient of friction of the surface was investigated through a ball-on-disk tribology test on the fabricated micro/nano-sized DLC pattern. The DLC pattern fabricated by the photolithography process showed a superior coefficient of friction to that of the general DLC sample. These results show that the decrease in the surface friction coefficient of the patterned DLC thin film is due to the reduction in the surface contact area owing to the modification of the micro/nano-texture of the surface as well as the low friction characteristics of the DLC.

FLOOR SLIPPERINESS MEASUREMENT UNDER SPILLAGE CONDITION

2015 ◽  
Vol 77 (27) ◽  
Author(s):  
Norazrin Azwani Ahmad ◽  
Masine Md. Tap ◽  
Ardiyanshah Syahrom ◽  
Jafri Mohd Rohani ◽  
Mohamed Fitri Johari
Keyword(s):  
Coefficient Of Friction ◽  
Friction Loss ◽  
Skid Resistance ◽  
Surface Conditions ◽  
The Coefficient Of Friction ◽  
Dry Conditions

To understand the risk of slipping accidents in the industry, it is imperative to measure the coefficient of friction (COF) between footwear and floor. In this study, COF values were measured for four types of floor with five surface conditions that represent dry conditions and four liquid spillage conditions. A portable skid-resistance tester was used to measure the COF with three footwear materials attached on the slider. The results show that the interaction between floor type, footwear material, and surface conditions was significant (p< 0.0001). Variation of COF value was found due to different footwear materials and floors involved during the interaction. The friction loss results also conclude that the COF became reduced significantly in all footwear-floor conditions (in the range of 17% to 78%) in the presence of spillage on the floor. 

scholarly journals Effect of Iron Oxide Nanoparticles on the Properties of Water-Based Drilling Fluids

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6718
Author(s):  
Muhammad Awais Ashfaq Alvi ◽  
Mesfin Belayneh ◽  
Sulalit Bandyopadhyay ◽  
Mona Wetrhus Minde
Keyword(s):  
Iron Oxide ◽  
Coefficient Of Friction ◽  
Drilling Fluid ◽  
Precipitation Method ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
The Coefficient Of Friction ◽  
Filtrate Loss ◽  
Co Precipitation ◽  
The Impact

In recent years, several studies have indicated the impact of nanoparticles (NPs) on various properties (such as viscosity and fluid loss) of conventional drilling fluids. Our previous study with commercial iron oxide NPs indicated the potential of using NPs to improve the properties of a laboratory bentonite-based drilling fluid without barite. In the present work, iron oxide NPs have been synthesized using the co-precipitation method. The effect of these hydrophilic NPs has been evaluated in bentonite and KCl-based drilling fluids. Rheological properties at different temperatures, viscoelastic properties, lubricity, and filtrate loss were measured to study the effect of NPs on the base fluid. Also, elemental analysis of the filtrate and microscale analysis of the filter cake was performed. Results for bentonite-based fluid showed that 0.019 wt% (0.1 g) of NPs reduced the coefficient of friction by 47%, and 0.0095 wt% (0.05 g) of NPs reduced the fluid loss by 20%. Moreover, for KCl-based fluids, 0.019 wt% (0.1 g) of additive reduced the coefficient of friction by 45%, while higher concentration of 0.038 wt% (0.2 g) of NPs shows 14% reduction in the filtrate loss. Microscale analysis shows that presence of NPs in the cake structure produces a more compact and less porous structure. This study indicates that very small concentration of NPs can provide better performance for the drilling fluids. Additionally, results from this work indicate the ability of NPs to fine-tune the properties of drilling fluids.

Study on the Friction and Wear Characteristics of Tungsten Carbide and Zirconium With Phosphor-Containing Liquid

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Myeong-Woo Ha ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee ◽  
Jong-Myung Choi ◽  
Jun-Wook An
Keyword(s):  
Tungsten Carbide ◽  
Coefficient Of Friction ◽  
Contact Surface ◽  
Friction And Wear ◽  
Yttrium Aluminum Garnet ◽  
Experimental Results ◽  
Wear Characteristics ◽  
Hard Materials ◽  
The Coefficient Of Friction ◽  
Friction And Wear Characteristics

The dispenser ejects the ceramic filler and phosphor-containing liquid for making various products. When the particle-containing liquid is ejected under high-velocity conditions, however, the ejection reliability decreases because of the wear of the contact surface between the rod and nozzle even though these components are made of hard materials. It is therefore necessary to characterize the friction and wear properties of the hard materials, tungsten carbide (WC) and zirconium (Zr), with the high-viscosity liquid-containing nitride or yttrium aluminum garnet (YAG) particles under reciprocating conditions. Particle contents of 15 wt.% and 30 wt.% are added to the liquid. A reciprocating test was implemented to this end, and WC and Zr specimens were used. The liquid used in the experiment contains nitride and YAG. The experimental results show that the particles inside the liquid are worn out, leading to particle lubrication and the decrease in the coefficient of friction. Also, it is confirmed that the more the particles are, the less the coefficient of friction is due to particle lubrication. For each experimental condition, the coefficient of friction is measured and compared. Moreover, the contact surface of the specimen is analyzed using an electron microscope, and a profilometer is used to measure the surface roughness of the specimen before and after the test. The reciprocation friction and wear characteristics of WC and Zr with phosphor-containing liquid are evaluated by analyzing the experimental results.

Coefficient of Friction for Aluminum Alloy Sheet in Contact with Polyurethane Rubber

2010 ◽  
Vol 26-28 ◽  
pp. 320-325 ◽  
Author(s):  
Li Li Wang ◽  
Dong Sheng Li ◽  
Xiao Qiang Li ◽  
Liang Wang ◽  
Wei Jun Yang
Keyword(s):  
Aluminum Alloy ◽  
Coefficient Of Friction ◽  
Normal Load ◽  
Orthogonal Experimental Design ◽  
Sliding Velocity ◽  
Stretch Forming ◽  
Forming Process ◽  
Alloy Material ◽  
The Coefficient Of Friction ◽  
The Impact

Stretch forming process of aircraft skin over reconfigurable compliant tooling is a new technology in skin manufacturing. During this process, the coefficient of friction is important for modeling accurately the process of stretch forming. The objective of this research is to measure the coefficient of friction for aluminum alloy in contact with polyurethane rubber in reciprocal sliding. An orthogonal experimental design was used to reveal the impact of four factors on the coefficient of friction, including lubrication, normal load, aluminum alloy material and sliding velocity. It is shown that lubrication is a major factor, sliding velocity is a minor factor. The influence of normal pressure is less than sliding velocity and the influence of aluminum alloy material is not very obvious. Finally, based on the experiment results, the selections of lubricant and stretching velocity are discussed in order to improve the process of stretch forming.

Coefficient of Wet Friction of Tire Treads

1967 ◽  
Vol 40 (4) ◽  
pp. 984-1013 ◽  
Author(s):  
W. F. Kern
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Contact Surface ◽  
Abrasion Resistance ◽  
Driving Safety ◽  
Motor Vehicles ◽  
Wet Friction ◽  
The Coefficient Of Friction

Abstract The schematic presentation in Figure 1 is an attempt to demonstrate the importance of friction coefficient in matters of driving safety and abrasion resistance, which are of interest to both tire manufacturers and users. References 1 to 3 present the viewpoint of road engineers, designers of motor vehicles, tire producers, rubber compounding experts, and various suppliers of different raw products. The numerous factors involved in producing skid resistant tires are summarized in Figure 2. From among such factors, we take up, here, only the tire element within the contact surface of the tire. The coefficient of friction for this element was investigated with test specimens, preferably under wet conditions, as a function of speed, temperature, and load, and against friction bases that exhibited a variety of grip characteristics. This coefficient of friction is affected by a number of other variables, Tables I and Ia, some of which will be discussed in this article.

Research Note: Reduction in Relaxation Oscillation (Stick-Slip) Amplitudes by Normal Excitation

1977 ◽  
Vol 19 (1) ◽  
pp. 42-44 ◽  
Author(s):  
J. B. Hunt
Keyword(s):  
Coefficient Of Friction ◽  
Contact Surface ◽  
Relaxation Oscillation ◽  
Research Note ◽  
Stick Slip ◽  
Resonant Frequencies ◽  
Maximum Value ◽  
The Coefficient Of Friction

When a slider-slideway system was excited by vibratory forces applied normally to the contact surface, it was found that at low sliding speeds the amplitude of stick-slip oscillation could be reduced to a negligible value. By exciting at one of the structural resonant frequencies of the system, the maximum value of the vibratory forces required was only a small percentage of the slideway load. The value of the coefficient of friction between the two surfaces was not reduced.

Friction Characteristics of Porous Rubber Under Wet Conditions

2009 ◽  
Author(s):  
Yutaro Kosugi ◽  
Tomoaki Iwai ◽  
Yutaka Shokaku ◽  
Naoya Amino
Keyword(s):  
Friction Force ◽  
Coefficient Of Friction ◽  
Contact Surface ◽  
Road Surface ◽  
Water Removal ◽  
The Road ◽  
Rubber Specimen ◽  
The Coefficient Of Friction ◽  
The Difference ◽  
Tread Rubber

In recent years, porous rubber has been used as a tread matrix for studless tires. It is said that the pores in the tread rubber remove water between the tire and the wet road surface; however, the water removal is not sufficiently well understood. In this study, a rotating rubber specimen was rubbed against a mating prism to observe the contact surface. The friction force was also measured simultaneously with observation of contact surface. The water entering the pores was distinguished by the continuity method. As the result of these experiments, the coefficient of friction for rubber having pores on the surface was found to be larger than that of rubber without pores. Moreover, the difference in the coefficient of friction for rubber specimens with and without pores tended to be larger at lower sliding speeds. No water entered pores 3mm or less in diameter at any sliding speed in this experiment. An experiment to make the rubber specimen collide with the mating prism was conducted since actual tires seem to be deformed by the vehicle weight, such that the tire surface might contact the road collisionally. In the resulting collision experiment, the water did enter pores 3mm in diameter.

Sign in / Sign up

Export Citation Format

Share Document