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 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.

scholarly journals ANALISIS TINGKAT KERUSAKAN JALAN DAN PENGARUNYA TERHADAP KECEPATAN KENDARAAN (STUDI KASUS: JALAN BLANG BINTANG LAMA DAN JALAN TEUNGKU HASAN DIBAKOI)

2018 ◽  
Vol 1 (3) ◽  
pp. 617-626
Author(s):  
Intan Wirnanda ◽  
Renni Anggraini ◽  
Muhammad Isya
Keyword(s):  
Regression Analysis ◽  
Condition Index ◽  
Road Surface ◽  
Road Segment ◽  
Primary Data ◽  
Vehicle Speed ◽  
Pavement Condition ◽  
The Road ◽  
Road Condition ◽  
Pavement Condition Index

Abstract: Abstract:Damage that occurs on some road segment causing huge lossed, especially for road users such as a long travel time, traffic jam, incident, and etc. In general there variety factor that caused of road damage such as age of the road that has been passed, puddle onthe road surface that cannot flow due to the poor drainage, trafic load excessively repetitive (overloaded). Which can cause life time is shorter than planning. Improper planning, poor monitoring and the implementation is not accordance with the existing plan, in addition to the lack of maintenance costs, delays in budget spending and priorities of improper handling also be the cause. It should be noted in order to avoid decreased in the quality of roads due to damage on road surface. The purpose of this study is to determined damage of the road extent/level using PCI method (Pavement Condition Index), determined the effect of road damage to the speed of vehicle using Regression Analysis method. This research take location in the road segment of Blang Bintang Lama road, and Teungku hasan Dibakoi each road is divided into 7 that being reviewed according to the level of damage. Primary data collected by field actual survey in the form of geometric data, extensive damage to the road, and vehicle speed. The results showed that damage of the road is very affected on the vehicle speed as seen on Blang Bintang Lama in V segment the value of PCI is 10 with failed condition and vehicle speed just reached 5.31 Km/h, while in VII segment PCI value is 87 with perfect road condition (excellent) vehicle speed reached to 58.34 Km/h, so that the equation obtained by regression analysis of Y = (3,571)(0,032) ͯ, while for segment in Teungku Hasan Dibakoi road as seen in III Segment PCI value is 4 with failed condition with vehicle speed just 4.95 Km/h, while in the VII segment PCI value is 88 with perfect road condition (excellent) vehicle speed reached to 68.64 Km/h, so the equation obtained by regression analysis of Y is Y= (3,822)(0,035) ͯ. This suggests that higher levels of road damage will affected to slower speed of vehicle, otherwise the lower level of damage road, will make the higher speed of vehicle.Abstrak: Kerusakan jalan yang terjadi di beberapa ruas jalan menimbulkan kerugian yang sangat besar terutama bagi pengguna jalan seperti waktu tempuh yang lama, kemacetan, kecelakaan, dan lain-lain. Secara umum penyebab kerusakan jalan ada berbagai sebab yaitu umur rencana jalan yang telah dilewati, genangan air pada permukaan jalan yang tidak dapat mengalir akibat drainase yang kurang baik, beban lalu lintas berulang yang berlebihan (overloaded) yang menyebabkan umur pakai jalan lebih pendek dari perencanaan. Perencanaan yang tidak tepat, pengawasan yang kurang baik dan pelaksanaan yang tidak sesuai dengan rencana yang ada, selain itu minimnya biaya pemeliharaan, keterlambatan pengeluaran anggaran serta prioritas penanganan yang kurang tepat juga menjadi penyebabnya. Hal ini perlu diperhatikan agar tidak terjadi penurunan kualitas jalan akibat kerusakan permukaan jalan. Tujuan penelitian ini adalah untuk menentukan tingkat dan jenis kerusakan jalan dengan menggunakan metode PCI (Pavement Condition Index), mengetahui pengaruh kerusakan jalan terhadap kecepatan kendaraan dengan menggunakan metode Analisis Regresi. Penelitian ini mengambil lokasi pada ruas Jalan Blang Bintang Lama dan ruas Jalan Teungku Hasan Dibakoi yang masing-masing jalan terbagi atas 7 segmen yang ditinjau menurut tingkat kerusakannya. Pengumpulan data primer dilakukan dengan survey aktual lapangan yaitu berupa data geometrik jalan, luas kerusakan jalan, dan kecepatan kendaraan. Hasil penelitian menunjukkan bahwa kerusakan sangat berpengaruh terhadap kecepatan kendaraan seperti yang terlihat pada ruas jalan Blang Bintang Lama pada segmen V dengan nilai PCI 10 kondisi jalan gagal (failed) dengan kecepatan kendaraan mencapai 5,37 Km/Jam, sedangkan pada segmen VII nilai PCI sebesar 87 dengan kondisi jalan sempurna (excellent) kecepatan kendaraan mencapai 58,34 Km/Jam, sehingga didapat persamaan dengan metode analisis regresi Y= (3,571)(0,032) ͯ, sedangkan untuk ruas Jalan Teungku Hasan Dibakoi terlihat pada segmen III nilai PCI 4 kondisi jalan gagal (failed) dengan kecepatan mencapai 4,95 Km/Jam, sedangkan pada segmen VII nilai PCI sebesar 88 dengan kondisi jalan sempurna (excellent) kecepatan kendaraan mencapai 68,64 Km/Jam, sehingga didapat persamaan dengan metode analisis regresi Y= (3,822)(0,035) ͯ. Hal ini menunjukkan bahwa semakin tinggi tingkat kerusakan jalan maka semakin rendah kecepatan kendaraan, sebaliknya semakin rendah tingkat kerusakan maka semakin tinggi kecepatan kendaraan.

THE INFLUENCE OF REDUCING TEMPERATURE ON CHANGING YOUNG’S MODULUS AND THE COEFFICIENT OF FRICTION OF SELECTED SLIDING POLYMERS

Tribologia ◽  
2018 ◽  
Vol 279 (3) ◽  
pp. 107-111
Author(s):  
Anita PTAK ◽  
Piotr KOWALEWSKI
Keyword(s):  
Friction Coefficient ◽  
Young’S Modulus ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Young's Modulus ◽  
Polymeric Materials ◽  
Kinetic Friction ◽  
Mechanical And Tribological Properties ◽  
Pin On Disc ◽  
The Coefficient Of Friction

For the polymeric materials, changing of the temperature causes changes in mechanical and tribological properties of sliding pairs. The goal of the present study was to determine the change in Young's modulus and kinetic friction coefficient depending of the temperature. Three thermoplastic polymers, PA6, PET and PEEK, were tested. These materials cooperated in sliding motion with a C45 construction steel disc. As part of the experiment, the Young's modulus tests (by 3-point bending method) and kinetic friction coefficient studies (using pin-on-disc stand) were carried out. The temperature range of mechanical and tribological tests was determined at T = –50°C±20°C. Comparing the results of mechanical and tribological properties, there is a tendency to decrease the coefficient of friction as the Young's modulus increases while reducing the working temperature.

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 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.

Discussion

1968 ◽  
Vol 41 (4) ◽  
pp. 807-831
Author(s):  
W. B. Horne
Keyword(s):  
Friction Coefficient ◽  
Water Depth ◽  
Surface Texture ◽  
Concrete Surface ◽  
Road Surface ◽  
Depth Effect ◽  
Large Aggregate ◽  
The Road ◽  
Wet Friction ◽  
Road Surfaces

Abstract Mr. W. B. Horne (NASA, Hampton, Virginia)—Results in the two papers are in agreement with NASA research results. The papers treated the subjects of tread material, tire construction, road surface texture, and tread design very thoroughly. But one essential ingredient to the problem has been left out of the paper discussions, and that is, the effect of water depth. The importance of the water depth effect, and the need to inform both public and government authorities about the importance of removing worn tires from automobiles for the safety of all, is discussed and illustrated very fully by Leland. An example of what happens when the water depth is 0.4 in. is shown in Figure 1. It can be seen that the water penetrates the tire imprint much more rapidly than in shallow water. The effect of road surface texture on braking friction coefficient is illustrated by the data shown in Figure 2. A smooth tread aircraft tire was successfully braked on five different road surfaces ranging in texture from a large aggregate asphalt surface to wet ice. These surfaces are classified as damp in wetness. The surfaces at the time of testing were wet to the touch but did not have any puddles or standing water. Under this condition, damp smooth concrete (smooth as a table top) gave friction values as low as wet ice. This drastic friction loss decreased as the road surface texture increased. It will be noted that the smooth aggregate asphalt data did not fall off in speed as was shown by Maycock in his paper in Figure 15. In Figure 3 the water depth on the smooth concrete and large aggregate asphalt surface was increased from a damp condition to a flooded condition (0.1–0.2 in.). The character of the friction changes of these surfaces due to change in water depth is remarkable. For example, the smooth concrete increased slightly in value. This is an apparent increase, however, because the deeper water produces a fluid drag term which adds to the tire-surface braking force and gives a higher friction coefficient. This is an academic point, however, since the smooth concrete surface is producing viscous hydroplaning even at low speeds. On the other hand, the asphalt surface which alleviated the viscous hydroplaning effect under damp conditions does not prevent dynamic hydroplaning from occurring to the tire when this surface is flooded to a depth of 0.1 to 0.2 in. To summarize, any surface must be evaluated under a range of water depths before its wet friction qualities can be properly evaluated. Smooth tread tires or badly worn patterned tires have demonstrated poor friction capabilities on most wet or flooded surfaces. For this reason, both aircraft and automobile tires should be removed and replaced before wear produces a smooth tread condition.

Experimental study on the relationship between the friction coefficient and interference in locomotive axle press-fitting

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ting Wang ◽  
Hanfei Guo ◽  
Jianjun Qiao ◽  
Xiaoxue Liu ◽  
Zhixin Fan
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Friction Pair ◽  
Rolling Stock ◽  
Content Type ◽  
Press Fitting ◽  
The Press ◽  
The Coefficient Of Friction ◽  
The Relationship ◽  
Locomotive Wheels

PurposeTo address the lack of data in this field and determine the relationship between the coefficient of friction and the interference between locomotive wheels and axles, this study evaluates the theoretical relationship between the coefficient of friction and the interference under elastic deformation.Design/methodology/approachWhen using numerical analyses to study the mechanical state of the contacting components of the wheels and axle, the interference between the axle parts and the coefficient of friction between the axle parts are two important influencing factors. Currently, as the range of the coefficient of friction between the wheel and axle in interference remains unknown, it is generally considered that the coefficient of friction is only related to the materials of the friction pair; the relationship between the interference and the coefficient of friction is often neglected.FindingsA total of 520 press-fitting experiments were conducted for 130 sets of wheels and axles of the HXD2 locomotive with 4 types of interferences, in order to obtain the relationship between the coefficient of friction between the locomotive wheel and axle and the amount of interference. These results are expected to serve as a reference for selecting the coefficient of friction when designing axle structures with the rolling stock, research on the press-fitting process and evaluations of the fatigue life.Originality/valueThe study provides a basis for the selection of friction coefficient and interference amount in the design of locomotive wheels and axles.

scholarly journals Applying the METRo model for road-condition forecasting in Norway 

2021 ◽  
Author(s):  
Stephanie Mayer ◽  
Fabio Andrade ◽  
Torge Lorenz ◽  
Luciano de Lima ◽  
Anthony Hovenburg ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Heat Dissipation ◽  
Road Traffic ◽  
Weather Forecast ◽  
Road Surface ◽  
Balance Model ◽  
Weather Station ◽  
The Road ◽  
Road Surface Temperature ◽  
Road Condition

<p>According to the 14<sup>th</sup> Annual Road Safety Performance Index Report by the European Transport Safety Council, annually more than 100,000 accidents occur on European roads, of which 22,660 people lost their lives in 2019. The factors contributing to road traffic accidents are commonly grouped into three categories: environment, vehicle or driver. The European accident research and safety report 2013 by Volvo states in about 30% of accidents contributing factors could be attributed to weather and environment leading for example to unexpected changes in road friction, such as black ice. In this work, we are developing a solution to forecast road conditions in Norway by applying the <em>Model of the Environment and Temperature of Roads – METRo</em>, which is a surface energy balance model to predict the road surface temperature. In addition, METRo includes modules for water accumulation at the surface (liquid and frozen) and vertical heat dissipation (Crevier and Delage, 2001). The road condition is forecasted for a given pair of latitude, longitude and desired forecast time. Data from the closest road weather station and postprocessed weather forecast are used to initialize METRo and provide boundary conditions to the road weather forecast. The weather forecasts are obtained from the THREDDS service and the road weather station data from the FROST service, both provided by MET Norway. We develop algorithms to obtain the data from these services, process them to match the METRo model input requirements and send them to METRo’s pre-processing algorithms, which combine observations and forecast data to initialize the model. In a case study, we will compare short-term METRo forecasts with observations obtained by road weather stations and with observations retrieved by car-mounted environmental sensors (e.g., road surface temperature). This work is part of the project <em>AutonoWeather - Enabling autonomous driving in winter conditions through optimized road weather interpretation and forecast</em> financed by the Research Council of Norway in 2020. </p>

scholarly journals Anisotropic Vibration Tactile Model and Human Factor Analysis for a Piezoelectric Tactile Feedback Device

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 448 ◽  
Author(s):  
Jichun Xing ◽  
Huajun Li ◽  
Dechun Liu
Keyword(s):  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Ciliary Body ◽  
Human Factor ◽  
Sliding Friction ◽  
Excitation Frequency ◽  
Tactile Feedback ◽  
Body Structure ◽  
Full Coverage ◽  
The Coefficient Of Friction

Tactile feedback technology has important development prospects in interactive technology. In order to enrich the tactile sense of haptic devices under simple control, a piezoelectric haptic feedback device is proposed. The piezoelectric tactile feedback device can realize tactile changes in different excitation voltage amplitudes, different excitation frequencies, and different directions through the ciliary body structure. The principle of the anisotropic vibration of the ciliary body structure was analyzed here, and a tactile model was established. The equivalent friction coefficient under full-coverage and local-coverage of the skin of the touch beam was deduced and solved. The effect of system parameters on the friction coefficient was analyzed. The results showed that in the full-coverage, the tactile effect is mainly affected by the proportion of the same directional ciliary bodies and the excitation frequency. The larger the proportion of the same direction ciliary body is, the smaller the coefficient of friction is. The larger the excitation frequency is, the greater the coefficient of friction is. In the local-coverage, the tactile effect is mainly affected by the touch position and voltage amplitude. When changing the touch pressure, it has a certain effect on the change of touch, but it is relatively weak. The experiment on the sliding friction of a cantilever touch beam and the experiment of human factor were conducted. The experimental results of the sliding friction experiment are basically consistent with the theoretical calculations. In the human factor experiment, the effects of haptic regulation are mainly affected by voltage or structure of the ciliary bodies.

Sign in / Sign up

Export Citation Format

Share Document