Energy Loss of Pneumatic Tires Under Freely Rolling, Braking, and Driving Conditions

1976 ◽  
Vol 4 (1) ◽  
pp. 3-15 ◽  
Author(s):  
D. J. Schuring

Abstract The concept of rolling resistance force is replaced by that of energy dissipated in unit distance traveled. The energy loss per unit distance, which is a function of slip angle, inclination angle, wheel torque, and other variables, is shown to reach a minimum under driving conditions. The new formula is compared with those given by Gough and by the Society of Automotive Engineers.

2019 ◽  
Vol 47 (1) ◽  
pp. 77-100
Author(s):  
Yi Li ◽  
Robert L. West

ABSTRACT Rolling resistance defined as energy loss per unit distance is well accepted by the tire science community. It is commonly believed that the dominant part of energy loss into heat is caused by the viscoelasticity of rubber compounds for a free-rolling tire. To calculate the rolling loss (hysteretic loss) into heat, a method based on tire forces and moments has been developed to ease required measurements in a lab or field. This paper points out that, by this method, the obtained energy loss is not entirely converted into heat because a portion of the consumed power is used to compensate mechanical work. Moreover, that part of power cannot be separated out by tire forces and moments–based experimental methods. The researchers and engineers have mistakenly ignored this point for a long time. The finding was demonstrated by a comparative analysis of a rigid, pure elastic, and viscoelastic rolling body. This research mathematically proved that rolling loss into heat is not resolvable in terms of tire forces and moments with their associated velocities. The finite element model of a free-rolling tire was further exercised to justify the concept. These findings prompt revisiting rolling resistance in a new way from the energy perspective. Moreover, an extended definition of rolling resistance is proposed and backward compatible with its traditional definition as a resistive force.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Ilham Habibi ◽  
Dedi Dwilaksana ◽  
Boi Arief Fachri

Rolling resistance is one of the main factors affecting the fuel efficiency of a vehicle. Rolling resistance is resistance to the wheels that will and has been rolled due to the force of friction between the wheels with the road surface of the wheel, due to the deformation process on the tire structure, contact area and road surface. Radial tires are tires where the reinforcing fibers on the carcass are arranged radially, have a greater ability to withstand lateral forces and generally have high ratio aspect ratio, widht smaller than the bias tires. The taguchi method is a new methodology in engineering aimed at improving product and process quality, minimizing cost and time. The purpose of this research is to know the air pressure influence, slip angle and tire width to rolling resistance. The research was conducted experimentally by using taguchi method. The result showed that the highest rolling resistance force accurred at a combination of air pressure of 175 kPa, 9o wheel slip angle and 90 mm widht of tire size of 36.914 N. While the smallest rolling resistance was obtained with a combination of parameters at the air pressure level of 325 kPa, slip angle 1o and the size of the 70 mm tire widht of 11.511 N at 350 rpm and normal load 580 N. From the result it can be concluded that the change in the level of the three air pressure parameters, the slip angle and size of tire width can affect the rolling resistance value.


1978 ◽  
Vol 6 (3) ◽  
pp. 176-188 ◽  
Author(s):  
A. Y. C. Lou

Abstract For radial and belted bias automobile tires having replicate bodies but different tread materials, the rolling resistance force was found to be nearly a linear function of the tread material loss ratio (fractional hysteresis) measured at either constant strain or constant stress. Loss ratio is calculated as the ratio of energy loss (hysteresis) to total energy input obtained from constant crosshead speed (sawtooth) loading cycles on an Instron tester. Good correlation was also observed between rolling resistance force and a viscoelastic index (loss tangent) obtained from sinusoidal strain cycles on a Rheovibron instrument. When related to energy loss of the tread, rolling resistance showed good correlation only for a series of natural rubber compounds of varied black content; a tread based on a solution styrene-butadiene rubber polymer fell outside the natural rubber pattern.


2018 ◽  
Vol 8 (1) ◽  
pp. 30
Author(s):  
I. Habibi ◽  
D. Dwilaksana ◽  
B.A. Fachri

Rolling resistance is one of the main factors affecting the fuel efficiency of a vehicle. Rolling resistance is resistance to the wheels that will and has been rolled due to the force of friction between the wheels with the road surface of the wheel, due to the deformation process on the tire structure, contact area and road surface. Radial tires are tires where the reinforcing fibers on the carcass are arranged radially, have a greater ability to withstand lateral forces and generally have high ratio aspect ratio, widht smaller than the bias tires. The taguchi method is a new methodology in engineering aimed at improving product and process quality, minimizing cost and time. The purpose of this research is to know the air pressure influence, slip angle and tire width to rolling resistance. The research was conducted experimentally by using taguchi method. The result showed that the highest rolling resistance force accurred at a combination of air pressure of 175 kPa, 9o wheel slip angle and 90 mm widht of tire size of 36.914 N. While the smallest rolling resistance was obtained with a combination of parameters at the air pressure level of 325 kPa, slip angle 1o and the size of the 70 mm tire widht of 11.511 N at 350 rpm and normal load 580 N. From the result it can be concluded that the change in the level of the three air pressure parameters, the slip angle and size of tire width can affect the rolling resistance value.


Author(s):  
Bartosz Wieczorek ◽  
Lukasz Wargula ◽  
Mateusz Kukla ◽  
Dominik Rybarczyk ◽  
Jan Górecki ◽  
...  

Abstract Purpose - The aim of this research was to analyse the impact of the human body position changes caused by propelling a wheelchair with the pushrim propulsion on the value of motion resistance force. Material and methods - The research was carried out in the group of six persons propelling a wheelchair whose frame was inclined, in respect to the horizontal plain, under the angle of 0°, 7° and 14°. The area of the position variability of the human body centre of gravity and the coefficients of wheelchair rolling resistance have been determined in the research. Results -The results obtained, depending on the wheelchair inclination angle, ranged from 9.82 N to 22.81 N. In addition, it has been determined that the percentage increase in rolling resistance force, with the body position proper for the initial propulsion phase, in relation to the body position for the final propulsion phase, amounted to: 35.6% for the inclination angle of 0°, 43.2% for the inclination angle of 7°, and 48.3% for the inclination angle of 14°. Conclusion - the research done demonstrated the impact of the centre of gravity position change on the change of motion resistance. Thus, the research supplemented knowledge with a new parameter which, like a surface type and wheel type, affects motion resistances.


1995 ◽  
Vol 23 (4) ◽  
pp. 256-265 ◽  
Author(s):  
P. S. Pillai

Abstract Energy loss per hour in a tire traveling at 80 km/h was obtained for a number of tires of different sizes and makes from the respective whole tire hysteresis loss of each tire. This loss value was then compared to the corresponding rolling loss obtained from the 1.7 m dynamometer rolling resistance method. The two methods agreed, indicating that the basic premise of the rolling resistance hysteresis ratio relation is valid.


2018 ◽  
Vol 11 (2) ◽  
pp. 135-145
Author(s):  
Guolin Wang ◽  
Xu Wu ◽  
Chen Liang ◽  
Jian Yang

2021 ◽  
pp. 17-27
Author(s):  
V.I. Kopotilov

The analysis of the physical essence of the kinematic and dynamic radii of the wheel is given. It is stated that the rolling radius of the wheel is a conditional kinematic parameter that characterizes only the rolling mode of the wheel. It is not the shoulder of all longitudinal forces acting on the wheel and should not be used to determine tractive forces, rolling resistance and wheel braking forces. Specific examples are given to illustrate the inappropriateness of using the kinematic radius to determine forces and moments. Keywords: elastic wheel, rolling radius, kinematic radius, dynamic radius, arm of force, traction force, rolling resistance force, braking force, rolling mode


2007 ◽  
Vol 80 (4) ◽  
pp. 580-607 ◽  
Author(s):  
M. Heinz ◽  
K. A. Grosch

Abstract A laboratory test method has been developed which allows the evaluation of diverse properties of tire tread compounds on the same sample. The laboratory test instrument consists of a rotating abrasive disk against which a rubber sample wheel runs under a given load, slip angle and speed. All three force components acting on the wheel during the tests are recorded. By changing the variable values over a wide range practically all severities encountered in tire wear are covered. The well-known fact that compound ratings depend on the road testing conditions is verified. Most compounds are only significantly distinguishable against a control over a limited range of testing conditions. Using a road test simulation computer program based on the laboratory data shows that not only ratings correspond to practical experience but also calculated absolute tire life times do. Tests on surfaces of different coarseness and sharpness indicate that sharp coarse surfaces give the best results with road tests, which of necessity are mostly carried out on public roads of differing constitution. The abrasive surface can be wetted with water at different temperatures and hence either the friction force at a locked wheel or the side force at a slipping wheel can be measured over a wide range of temperatures and speeds. At small slip angles the side force is dominated by dynamic cornering stiffness of the compound, at large slip angles by the friction coefficient. In this case, too, good correlations to road experience exist over a limited range of testing conditions. Low water temperatures and low slip speed settings in the laboratory produce side force ratings, which correlate closely with ABS braking on the road High and higher slip speeds give ratings in close agreement with locked wheel braking on the road. A heatable/coolable disk enables traction measurements on ice and newly abrasion measurements on surfaces at elevated surface temperature. Ice surface temperatures between −5 °C and −25 °C are possible. Friction measurements show that the difference in compound rating between summer and winter compounds is maintained over the whole temperature range. New investigations show not only a differentiation between different winter tire treads qualities but also an excellent correlation between tire and laboratory results. As a new topic side force measurements on dry surfaces highlight the correlation to dry handling of tires. The tire tread compound contributes to this performance through its shear stiffness and its friction coefficient. The shear stiffness contributes to the response of the tire in directional changes. The friction coefficient determines the maximum force, which can be transmitted. A simple operation possibility for evaluation of determined side forces is demonstrated. In addition to antecedent investigations the rolling resistance of the rubber wheel can be measured over a range of loads and speeds with the slip angle set at zero. Again for these new results good correlations are achieved with practical experience. In particular, the dependence of the rolling resistance on the velocity and loads are pointed out. Ultimately a good correlation between tire test and laboratory test results was demonstrated.


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