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.

scholarly journals Analisa Koefisien Gesek Kinetis Terhadap Struktur Permukaan Jalan Akibat Beban Dinamik Mobil

2018 ◽  
Vol 1 (1) ◽  
pp. 047-051
Author(s):  
Muhammad Nuh Hudawi Pasaribu ◽  
Muhammad Sabri ◽  
Indra Nasution
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Surface Texture ◽  
Road Surface ◽  
Vehicle Speed ◽  
Kinetic Friction ◽  
The Road ◽  
Road Condition ◽  
Asphalt Road ◽  
The Coefficient Of Friction

Tekstur permukaan jalan umumnya terdiri dari aspal dan beton. Kekasaran tekstur permukaan jalan dapat disebabkan oleh struktur perkerasan dan beban kendaraan. Kekasaran tekstur permukaan jalan, bebandan kecepatan kendaraan akan mempengaruhi koefisien gesek. Untuk mengetahui nilai koefisien gesek dilakukan penelitian dengan melakukan variasi beban mobil (Daihatsu Xenia, Toyota Avanza, Toyota Innova dan Toyota Yaris) terhadap kontak permukaan jalan (aspal dan beton) dan kecepatan kendaraan. Hasil penelitian menunjukkan bahwa massa, lebar kontak tapak ban terhadap permukaan jalan dan kecepatan sangat mempengaruhi nilai koefisien gesek kinetis. Koefisien gesek kinetis yang terbesar untuk ketiga kontak permukaan jalan (aspal lama IRI 10,1, Aspal baru IRI 6,4 dan beton IRI 6,7) dengan menggunakan mobil Daihatsu Xenia terjadi pada kondisi jalan beton yaitu 0,495 pada kecepatan 35 Km/Jam. Koefisien kinetis jalan beton > 52 % dibandingkan jalan aspal pada parameter IRI yang sama (6-8).Koefisien gesek kinetis > 0,33 diperoleh di jalan beton pada kecepatan 30 – 40 Km/Jam   The texture of road surface generally consists of asphalt and concrete. The roughness of the road surface texture could be caused by the structure of the pavement and the load of the vehicles. Roughness of road surface texture, load and speed of vehicles would affect to the coefficient of friction. This research was carried out to find out the value of the coefficient of friction by using various load of cars (Daihatsu Xenia, Toyota Avanza, Toyota Innova and Toyota Yaris) on road surface contact (asphalt and concrete) and vehicle speed. The result showed the mass, the width of the tire tread contact to the road surface, and speed very influenced the coefficient value of kinetic friction. The biggest kinetic friction coefficient for all three road surface contacts (IRI 10.1 old asphalt, IRI 6.4 and IRI 6.7) using the Daihatsu Xenia was on the concrete road condition i.e. 0.495 on a speed of 35 km/hour. The concrete road kinetic coefficient was >52% compared to the asphalt road in the same IRI parameter (6-8). The kinetic friction coefficient >0.33 was obtained on the concrete road on a speed of 30 - 40 km/hour.

scholarly journals Efficiency of sorbents used to restore the grip of the surface of the oily road

2018 ◽  
Vol 247 ◽  
pp. 00024
Author(s):  
Mirosław Sobolewski ◽  
Dominika Gancarczyk ◽  
Piotr Książek
Keyword(s):  
Coefficient Of Friction ◽  
Static Friction ◽  
Road Surface ◽  
Asphalt Pavements ◽  
Fire Departments ◽  
Initial Coefficient ◽  
The Road ◽  
Road Users ◽  
The Coefficient Of Friction ◽  
High Degree

The use of sorbents is one of the methods most commonly used by the fire departments to remove spilled hydrocarbon liquids. Sorbents approved for use by fire brigades must meet the requirements of the Ministry of Internal Affairs. However, this requirement does not include the assessment of the degree of roughness of the road surface after removal of oily spills. The high degree of restoration of road surface grip is extremely important for the safety of road users. The article presents the results of research on the effectiveness of restoring the coefficient of friction by different sorbents. The tests were carried out for three different asphalt pavements, determining the coefficients of friction for dry, wet and oily surfaces and after applying sorbents. Static friction coefficients were determined by measuring the angle of the inclination of the tested surface specimen, at which the probe imitating the car tire slid. It turned out that none of the used sorbents fully restored the initial coefficient of friction on the asphalt surface. The use of professional sorbents allowed for the restoration of about 80% of the initial coefficient of friction of the dry surface. Significantly poorer results were obtained for the most commonly used sorptive replacement materials, i.e. sand or sawdust.

Analysis of the inertial propulsion concept

2020 ◽  
pp. 12-19
Author(s):  
A. A. Sabirzyanov ◽  
Keyword(s):  
Remote Control ◽  
Friction Force ◽  
Coefficient Of Friction ◽  
Average Velocity ◽  
Classical Mechanics ◽  
Average Speed ◽  
The Coefficient Of Friction ◽  
The Difference ◽  
The Right ◽  
Propulsion Concept

In this paper, an inertial device of the simplest design is proposed, which allows us to visually analyze the principle of its operation. The device is a radio-controlled car placed on the bottom of a long light cardboard box. The box is on the table. Using the remote control, the car accelerates and collides with one of the walls. On impact, the box moves across the table. Next, the car is taken to the opposite wall by the remote control without a collision. Then the process is repeated, as a result of which the device jerks along the table in one direction (in the example - to the right). The advantage of this method of control is that it is contactless, the disadvantage is that it is manual. In the framework of classical mechanics, the average speed of the box movement on the table is calculated. It depends on the ratio of the mass of the car and the box, the proportion of weight that falls on the driving wheels, the coefficient of friction between the wheels and the bottom of the box, the coefficient of friction between the box and the table, the difference in the length of the box and the car. It is shown that the average speed with a decrease in the friction force on the side of the support should first increase, and with a further decrease in friction - decrease. A condition is found under which the dependence of the average velocity on the friction force has a maximum.

scholarly journals FORMS OF x x   s – DIAGRAMS OF AN AUTOMOBILE TYRE

2017 ◽  
Author(s):  
E.V. Balakina
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Lateral Force ◽  
Road Surface ◽  
Vehicle Stability ◽  
The Road ◽  
The Coefficient Of Friction ◽  
Longitudinal Slip ◽  
The Moment ◽  
Friction Interaction

Vehicle stability, handling and braking properties significantly depends on the friction interaction between a tyre and the road surface. Index of the friction interaction is the coefficient of friction in different coordinates. The friction coefficient is generally calculated as a function of the coefficient of the longitudinal slip of the wheel x  f (sx ) . The lateral force significantly affects the coefficient of friction. In different cases the lateral force can occur either before or after occurrence of the braking moment on the wheel. The purpose of the study is to investigate the effect of different sequence of occurrence of the lateral force and the braking moment on a wheel on the friction properties of the tyre with a solid road surface. The author have developed the methods which allows considering the sequence of occurrence of the lateral force and the moment on the wheel in the calculation of x  sx – diagrams.

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.

ON THE FRICTION OF INFLATED RUBBER TIRES ON ICE

1958 ◽  
Vol 36 (5) ◽  
pp. 599-610 ◽  
Author(s):  
C. D. Niven
Keyword(s):  
Friction Force ◽  
Coefficient Of Friction ◽  
Sliding Friction ◽  
Rolling Friction ◽  
The Other ◽  
Slow Speed ◽  
Dry Ice ◽  
Load Axis ◽  
Cold Room ◽  
The Coefficient Of Friction

The friction on ice of some small inflated rubber tires was measured on a turntable in a cold room. When rolling-friction force was plotted against load, the relation was either linear or slightly curved away from the load axis; such curvature implies that Thirion's Law does not hold for rolling friction. On the other hand when sliding-friction force was plotted against load the curvature was toward the load axis as would be expected if Thirion's Law applied. The coefficient of friction can go as low as 0.01 or even lower for a hard-pumped tire when the temperature is near 0 °C, but at −1 °C. rolling friction on dry ice is quite appreciable. The results refer only to measurements at very slow speed.

scholarly journals Determination of tangential properties of a single pneumatic tire in the vehicle braking mode of a vehicle

2021 ◽  
pp. 28-34
Author(s):  
Valeriy Klimenko ◽  
Denis Kapski ◽  
Dmytro Leontiev ◽  
Oleksandr Kuripka ◽  
Andrii Frolov
Keyword(s):  
Coefficient Of Friction ◽  
Simulation Modeling ◽  
Torsional Rigidity ◽  
Dynamic Change ◽  
Twist Angle ◽  
Road Surface ◽  
Pneumatic Tire ◽  
The Road ◽  
On The Road ◽  
Pneumatic Tires

Problem. In the event of circumstances that may cause a traffic accident (accident), drivers apply emergency braking, which usually leads to the blocking of car wheels and the formation on the road surface of track information from pneumatic tires. If automated brake force control systems are installed in the brake actuator of the vehicle, the tracking information from the pneumatic tires may be absent or weak, and the braking efficiency of the wheeled vehicle will depend on the angular deformation of the tire relative to the road surface, which in turn is limited. coupling properties in the contact spot "tire-road surface". Goal. The aim of the work is to improve the method of determining the angle of twist of the pneumatic tire of a single car wheel in the mode of its braking by taking into account the effects of the coefficient of friction-sliding on roads with high traction. Methodology the peculiarities of twisting the pneumatic tire of a car wheel with a single busbar in the mode of vehicle braking on roads with low and high coefficient of friction - sliding are considered. The analysis of the model of dynamic change of the tire twist angle depending on the sliding of the tire tread elements in the spot of contact with the road surface is performed, and the results of simulation modeling are obtained, which are confirmed by experimental experiments. Originality. An empirical dependence is proposed, which takes into account the nature of the decrease in the value of the angle of twist of the tire on roads with high traction properties. Practical value. The obtained results of simulation modeling according to the proposed dependence determine that the highest indicators of torsional rigidity of the pneumatic tire are reached at a tire pressure of 0.8 MPa and a vertical load on it of about 2.6 104 N.

Determination of Tire-Road Friction Coefficients for Skid Mark Analysis

1985 ◽  
Vol 13 (1) ◽  
pp. 41-64
Author(s):  
W. R. Garrott ◽  
D. A. Guenther
Keyword(s):  
Experimental Study ◽  
Coefficient Of Friction ◽  
Friction Coefficients ◽  
Pickup Truck ◽  
The Road ◽  
Heavy Trucks ◽  
Road Friction ◽  
Brake Application ◽  
The Coefficient Of Friction

Abstract An experimental study was made to compare the validities of methods currently used by accident reconstructionists to determine the coefficient of friction between the road and the vehicle tires at the time of an incident. This value could then be used in conjunction with skid mark length and vehicle weight to calculate the prebraking speed of the vehicle. Three automobiles and three trucks with a variety of tires and loadings were used on a variety of pavements. The accuracy and area of applicability of each of four methods for obtaining friction coefficients were determined by relating the prebraking speed calculated from each to the actual speed at the time of brake application. All four methods were satisfactory for automobiles and the pickup truck used, but only two were acceptable for heavy trucks. The most valid coefficients are obtained from skid mark lengths obtained under conditions duplicating those in an incident.

Effect of surface structure, composition and texture on friction under boundary conditions

1952 ◽  
Vol 212 (1111) ◽  
pp. 508-512
Keyword(s):  
Oxide Film ◽  
Boundary Conditions ◽  
Coefficient Of Friction ◽  
Substrate Material ◽  
Pure Aluminium ◽  
Surface Layers ◽  
The Coefficient Of Friction ◽  
The Difference ◽  
Frictional Behaviour ◽  
Effect Of Surface

The coefficient of friction of surfaces lubricated under boundary conditions may be profoundly affected by such factors as the degree of working of the substrate material, the nature of the oxide film and the degree of roughness of the surface. Experiments are described wherein the frictional behaviour of surfaces of stainless steel specimens prepared in various ways was compared. The worked surface layers in these particular experiments appear to increase the value of the coefficient of friction, but the effect of surface texture is of predominant importance. The effect of different oxide films is best illustrated by reference to pure aluminium, the surface of which has been oxidized under different environmental conditions. The constitution of the oxide film formed is modified with a consequent effect on boundary friction. When the friction of rough and smooth surfaces is compared, the difference in behaviour appears to be qualitative rather than quantitative.

The Coefficients of Friction between Rubber and Other Materials. Frictional Grip of Rubber-Tired Wheels

1930 ◽  
Vol 3 (1) ◽  
pp. 67-73
Author(s):  
R. Ariano
Keyword(s):  
Coefficient Of Friction ◽  
Static Friction ◽  
Systematic Difference ◽  
Road Surface ◽  
Dynamic Friction ◽  
Simple Relationship ◽  
Inflation Pressure ◽  
The Coefficient Of Friction ◽  
Individual Design ◽  
Increasing Load

Abstract (i) The coefficients of friction (ƒI and ƒnI) of rubber tires on dry non-dusty surfaces are practically independent of the load on the wheel, and (with pneumatics) of the inflation pressure; on muddy surfaces the coefficients (especially ƒnI tend to decrease with increasing load. (ii) Dust, mud, or water reduces the friction with rubber tires, but not with iron tires. (iii) The tread pattern reduces the friction on dry surfaces, but increases it on muddy surfaces. (iv) There is no systematic difference between pneumatic, semi-pneumatic (cushion) and solid tires as regarda coefficient of friction; the details of individual design and material are the deciding factors; this is in agreement with the results of Bredtscheiner (Verkehrstechnik, 1922; see Schaar, “Die Beanspruchung der Strassen durch die Kraftfahrzeuge,” Zementverlag, 1925). (v) There is no simple relationship between the coefficient of friction and the compressibility or area of contact of the tire. (vi) The static friction perpendicular to the direction of travel is greater than in this direction. (vii) The coefficient of friction depends on the type of road surface, its de-formability, and especially on the presence or absence of dust, mud, or water. (viii) Rubber tires have a much higher coefficient of friction than iron tires, especially on dry hard surfaces. (ix) The static friction is 10 to 20 per cent higher than the dynamic friction.

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