Studying road roughness effect on rolling resistance using brush tyre model and self-affine fractal surfaces

2016 ◽  
pp. 287-294
Author(s):  
Seunggu Kang ◽  
Hasan Ozer ◽  
Imad L. Al-Qadi ◽  
Billie F. Spencer

Rolling resistance because of road roughness is often the largest contributor to energy consumption in the environmental assessment of pavement life cycle. Although fuel consumption of passenger vehicles caused by roadway roughness is well studied, further research is needed for truck fuel consumption models utilizing mechanistic approaches. Existing models estimating trucks’ excess fuel consumption because of rolling resistance are based on empirical models or simplified mechanistic models such as the quarter car model. Such approaches may not fully capture the complex dynamic motion of a tractor-trailer. This study suggests a stochastic method utilizing the analytical solution based on a tractor-trailer model to calculate excess truck fuel consumption because of roughness and speed. The illustrative examples show that excess truck fuel consumption tends to increase nonlinearly with roughness; fuel consumption increases with speed but drops after 104 km/h (65 mph) because of a rapid increase in aerodynamic drag at very high speeds. The effect of new generation wide-base tires (NG-WBT) in lieu of the standard dual tire assembly was studied using the introduced model. Results indicate that NG-WBT reduced excess fuel consumption because of roughness by 11% and 8% at 56 km/h and 80 km/h (35 mph and 50 mph), respectively. Finally, Monte Carlo simulation was conducted at two speeds and the simulation results were in agreement with the analytical solution. The results from the developed model and the validation using illustrative examples confirm the impact of roughness and speed on truck fuel consumption in a quantitative manner.


2013 ◽  
Author(s):  
Aref M. A. Soliman ◽  
Mina M.S. Kaldas ◽  
Sayed A. Abdallah

Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.


1989 ◽  
Vol 17 (1) ◽  
pp. 66-84
Author(s):  
A. R. Williams

Abstract This is a summary of work by the author and his colleagues, as well as by others reported in the literature, that demonstrate a need for considering a vehicle, its tires, and the road surface as a system. The central theme is interaction at the footprint, especially that of truck tires. Individual and interactive effects of road and tires are considered under the major topics of road aggregate (macroscopic and microscopic properties), development of a novel road surface, safety, noise, rolling resistance, riding comfort, water drainage by both road and tire, development of tire tread compounds and a proving ground, and influence of tire wear on wet traction. A general conclusion is that road surfaces have both the major effect and the greater potential for improvement.


2001 ◽  
Vol 29 (3) ◽  
pp. 134-154 ◽  
Author(s):  
J. R. Luchini ◽  
M. M. Motil ◽  
W. V. Mars

Abstract This paper discusses the measurement and modeling of tire rolling resistance for a group of radial medium truck tires. The tires were subjected to tread depth modifications by “buffing” the tread surface. The experimental work used the equilibrium test method of SAE J-1269. The finite element analysis (FEA) tire model for tire rolling resistance has been previously presented. The results of the testing showed changes in rolling resistance as a function of tread depth that were inconsistent between tires. Several observations were also inconsistent with published information and common knowledge. Several mechanisms were proposed to explain the results. Additional experiments and models were used to evaluate the mechanisms. Mechanisms that were examined included tire age, surface texture, and tire shape. An explanation based on buffed tread radius, and the resulting changes in footprint stresses, is proposed that explains the observed experimental changes in rolling resistance with tread depth.


2011 ◽  
Vol 39 (4) ◽  
pp. 223-244 ◽  
Author(s):  
Y. Nakajima

Abstract The tire technology related with the computational mechanics is reviewed from the standpoint of yesterday, today, and tomorrow. Yesterday: A finite element method was developed in the 1950s as a tool of computational mechanics. In the tire manufacturers, finite element analysis (FEA) was started applying to a tire analysis in the beginning of 1970s and this was much earlier than the vehicle industry, electric industry, and others. The main reason was that construction and configurations of a tire were so complicated that analytical approach could not solve many problems related with tire mechanics. Since commercial software was not so popular in 1970s, in-house axisymmetric codes were developed for three kinds of application such as stress/strain, heat conduction, and modal analysis. Since FEA could make the stress/strain visible in a tire, the application area was mainly tire durability. Today: combining FEA with optimization techniques, the tire design procedure is drastically changed in side wall shape, tire crown shape, pitch variation, tire pattern, etc. So the computational mechanics becomes an indispensable tool for tire industry. Furthermore, an insight to improve tire performance is obtained from the optimized solution and the new technologies were created from the insight. Then, FEA is applied to various areas such as hydroplaning and snow traction based on the formulation of fluid–tire interaction. Since the computational mechanics enables us to see what we could not see, new tire patterns were developed by seeing the streamline in tire contact area and shear stress in snow in traction.Tomorrow: The computational mechanics will be applied in multidisciplinary areas and nano-scale areas to create new technologies. The environmental subjects will be more important such as rolling resistance, noise and wear.


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