Tire Rolling Resistance Research Articles

Using Epoxidized Solution Polymerized Styrene-Butadiene Rubbers (ESSBRs) as Coupling Agents to Modify Silica without Volatile Organic Compounds.

Rubber used in tire is usually strengthened by nanofiller, and the most popular nanofiller for tire tread rubber is nano silica, which can not only strengthen rubber but also lower the tire rolling resistance to reduce fuel consumption. However, silica particles are difficult to disperse in the rubber matrix because of the abundant silicon hydroxyl on their surface. Silane coupling agents are always used to modify silica and improve their dispersion, but a large number of volatile organic compounds (VOCs) are emitted during the manufacturing of the nanosilica/rubber composites because of the condensation reaction between silane coupling agents and silicon hydroxyl on the surface of silica. Those VOCs will do great harm to the environment and the workers’ health. In this work, epoxidized solution polymerized styrene-butadiene rubbers (ESSBR) with different epoxy degrees were prepared and used as macromolecular coupling agents aimed at fully eliminating VOCs. Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) analyses verified that the different ESSBRs were successfully synthesized from solution polymerized styrene-butadiene rubbers (SSBR). With the help of the reaction between epoxy groups and silicon hydroxyl without any VOC emission, nanosilica can be well dispersed in the rubber matrix when SSBR partially replaced by ESSBR which was proved by Payne effect and TEM analysis. Dynamic and static mechanical testing demonstrated that silica/ESSBR/SSBR/BR nanocomposites have better performance and no VOC emission compared with Bis-(γ-triethoxysilylpropyl)-disulfide (TESPD) modified silica/rubber nanocomposites. ESSBR is very hopeful to replace traditional coupling agent TESPD to get high properties silica/rubber nanocomposites with no VOCs emission.

Enhanced covalent interface, crosslinked network and gas barrier property of functionalized graphene oxide/styrene-butadiene rubber composites triggered by thiol-ene click reaction

The high gas barrier property of a rubber composite is of great significance for reducing the exhaust gas emissions due to tire rolling resistance and hence the contribution this factor makes to environmental protection. Enhanced covalent interfaces and crosslinked networks are crucial to the gas barrier property of rubber composites. In this research, γ-mercaptopropyltriethoxysilane (MPS) modified GO (MGO)/styrene-butadiene rubber (SBR) composites were prepared by a synergetic strategy of latex compounding method and thiol-ene click reaction. It was found that the mercapto groups in MGO reacted with the vinyl groups in SBR molecules through thiol-ene click reaction during the crosslinking process at 150 °C, thus forming strong chemical interactions at the interface in the form of GO-MPS-rubber and enhanced crosslinked networks. Meanwhile, the strong interface promoted the dispersion of MGO in SBR. The uniform dispersion of MGO, strong interface between MGO and SBR molecules and enhanced crosslinked networks resulted in improved mechanical and gas barrier properties. When filling 5 phr fillers, the tensile strength and gas barrier properties of an MGO/SBR composite improved by 19.0% and 37.5%, respectively, relative to the comparing GO/SBR composite.

Experimental Comparison of Speed-Dependent Rolling Coefficients in Small Cycling Tires

ABSTRACTIn this article, the methodology and results of an experimental campaign on small and slick bicycle tires are presented. The test was developed to compare the rolling resistance of tires to be used in high-speed competitions for streamlined human-powered vehicles. After an explanation of the theoretical background for the measurement, the test-rig and the adopted procedure to measure and subtract aerodynamic effects are presented. The obtained data show that the rolling resistance coefficient has a nonlinear dependency from the speed between 45 and 145 km/h. The data comparison points out a decrease in rolling losses up to 54% by switching from a butyl to latex inner tube on the same tire, whereas no significant difference is detected between the latex tube and tubeless configuration. An estimation of the impact on racing performance is provided, showing that selecting the best option could save up to 19% of the overall effort energetic cost, which means a higher final speed can be achieved with the same rider effort. Finally, a speculative analysis is proposed that considers different functions to fit the obtained data, pointing out the need for experimental measurements on the very-low-speed region to achieve a better understanding of the entire rolling resistance behavior with respect to speed.

Selection of the required deceleration for high-mobility wheeled vehicles with wear resistant brake systems

Analysis of the driving cycles of the high-mobility wheeled vehicles shows that the driver tries to provide a high speed when performing maneuvers. This results in high loads both on the powerplant and the brake system. During quick changes of the driving modes, the service brake system has to dissipate a lot of energy, which may cause overheating of its working elements and changes (deterioration) in their frictional properties or their increased wear, or even a failure of the system. The article reveals the method for selection of the required deceleration of high-mobility wheeled vehicles with wear resistant brake systems providing higher speeds and considerably lower loads on the service brake system and increased life of the frictional elements. The method is based on the generation of the driving cycle, which is close to the real-life operation conditions of the high-mobility wheeled vehicles with the use of stochastic data on the roads. Thus, driving conditions are described as realizations of random functions of such external factors as the trajectory curvature, the friction coefficient between the tire and the road, and the tire rolling resistance coefficient. The driving cycle is generated with allowance for the vehicle stability, the powerplant performance, the physiological capability of the driver to withstand accelerations, and the maximum available deceleration. By varying the vehicle deceleration we can find the dependence of the vehicle average speed on its deceleration. The data obtained during the analysis helps to select the deceleration which can be effectively provided by the wear resistant brake system without the use of the service brake system. A method for selection of the wear resistant brake system characteristics with the use of stochastic data on the driving conditions. The method allows selection of the torque – speed curves of the units of a wear resistant brake system providing required mobility of the vehicle.

Variable Modulus Approach to Optimize Tire Rolling Resistance

ABSTRACT Tire rolling resistance plays a vital role in a vehicle's fuel consumption, which needs to be continuously optimized. Such targets can be met only through the combination of advanced processing of materials and new technologies together with innovative tire designs. Achieving the optimal rolling resistance of a tire requires effective distribution of the rolling loss contributor (i.e., the resultant of the modulus, volume, and dissipation). The contribution of the three tire deformation states (e.g., equal strain, equal stress, and equal energy) on the tire's rolling loss vary with the modulus. As proposed in the literature[1–3], the deformation index has proven to be a useful tool for identifying different states of deformation in the tire. This approach is explored in this article. Within the context of the nonlinear finite element method, a novel approach is proposed for optimization of tire rolling resistance. The proposed approach is implemented on both passenger car and commercial vehicle tires, including cross-ply tires. As a result of this concept, up to 10% improvement in rolling resistance has been achieved, depending on the chosen tire. The developed procedure has been implemented in the commercial finite element simulation tool Abaqus and hence can be directly used as a design tool for any tire the during predesign phase itself.

Rolling Resistance Evaluation of Winter Tires on In-Service Road Surfaces

ABSTRACT Rolling resistance, the energy dissipated due to the rolling movement of a pneumatic tire over a surface, is a relevant factor that should be considered when aiming at a more energy efficient road infrastructure as well as for reducing CO2 emissions. The energy dissipation, as a result mainly of hysteretic losses, is dependent on the tire, the road surface, and the operating temperature, among other factors. In this study, 50 different tires of five different types—all-season tires, summer tires, winter tires without studs, winter tires with studs, and winter tires with hard particles—were evaluated with respect to rolling resistance on two different road surfaces, at three different test speeds and different states of tire wear. In addition to the full-scale field tests, a drum facility was used to evaluate rolling resistance of the same tires in a more controlled environment. This resulted in more than 500 measurements that were analyzed in this paper. Previously, no data regarding rolling resistance of studded winter tires had been published, and there have been very few studies comparing measurements on drums with measurements on road pavements. In the field, rolling resistance was significantly depending on tire type, and many tested tires performed differently on the two surfaces. No significant correlation was found between labeled tire values and rolling resistance measured on roads, or between rolling resistance measured on roads and on a drum facility. Better correlations were found between labeled tire values and our own drum results. This calls for a review of the relevance of the energy labeling procedure.

Enhancement of the tyre rolling resistance testing machine

Rubber tree is an outstanding product in commercial area of Thailand. Tyre is one of the prominent and downstream products as components in the automotive industry with a high production capacity. While tyres are used widely, a regulation for the rolling resistance of tyres has been set up by the European Commission. Therefore, the operators must test their products. By the high costs for the testing before certification, the researchers realize the limitation of the test equipment suffering with the small and medium enterprises that do not have access to check their tyres. This is the weakness of the tyre industry in Thailand. Therefore, the low-cost of tyre rolling resistance testing machine has been built in accordance with the UNECE Regulation No. 117 which is accepted worldwide. As a result, the in-house tyre rolling resistance testing machine is compared with the imported one in terms of production cost. The budget can be reduced up to 50% since the test equipment can be produced with currently technology in the country. Moreover, this is the self-reliance of technological machinery industry. For the working result, it was found that the vibration level of tyre rolling resistance testing machine consented to the standard ISO 10816. Besides, the experimental results of tyre rolling resistance coefficient is compliance with the requirements UNECE Regulation No. 117 Annex 6 and also verified by the international authority (TUV Rheinland Thailand Ltd). It can reduce the limitation in terms of the testing and also support the economic expansion of the production of quality tyres in the country to be accepted in international level.

Statistical Analysis of the Impact of Vehicle Running-in Distance on Mechanical Resistance

Certified testing of motor vehicle driving resistance, fuel economy and emissions requires that the vehicle has reached the target distance specified for each country through running-in. In general, motor vehicles experience different tire wear and internal resistance profiles from their moving parts, including the brake, hub bearing, drive shaft and transmission, depending on how they have performed running-in over what range. This means that such differences can result in a discrepancy in the level of mechanical resistance that consists of tire rolling resistance and internal resistance. There is thus a potential impact on the fuel economy and emissions as tested by the chassis dynamometer. In this study, the nomenclatures define where the running-in testing takes place (“Location”), how the testing is performed (“Mode”) and over which distance the testing takes place (“Distance”) as the factors having the major impact on the mechanical resistance of a motor vehicle. Then the mechanical resistance was measured under different running-in distances using a chassis dynamometer and the determination was made on how the resistance decrease over the range to understand statistically how Location and Mode affect the reduction in mechanical resistance under different Distances. This study was also evaluated on which running-in test mode is the best for fuel economy and emissions certification through total cost analysis over the 6,500 km running-in distance. In addition, the process to identify the impact of vehicle running-in test conditions on the reduction in the mechanical resistance of the vehicle was suggested.

Rolling Resistance of Wheelchair tire

Rolling Resistance of Wheelchair tire

Исследование сопротивления качению двухколесных транспортных средств

Rolling resistance of a bicycle tire is the main factor that affects the characteristics of two-wheeled vehicles. The study of rolling resistance allows better evaluating the advantages of different wheel diameters. Since rolling resistance is an indicator of the vehicle behavior on a particular terrain, it can be considered an objective parameter for comparing the characteristics of two wheel sizes (26 and 29 inches). The purpose of this study was to evaluate rolling resistance of mountain bikes, depending on several parameters: wheel diameter, terrain type, cyclist mass, tire pressure, and suspension type.

Prediction and validation of terramechanics models for estimation of tyre rolling resistance coefficient

Prediction and validation of terramechanics models for estimation of tyre rolling resistance coefficient

Prediction and validation of terramechanics models for estimation of tyre rolling resistance coefficient

This research focuses on prediction of the rolling resistance coefficient of an agriculture tyre using finite element analysis (FEA) technique, and Bekker and Wismer-Luth models. The tyre-soil interaction is modelled using FEA and smoothed-particle hydrodynamics (SPH) techniques in Visual Environment's PAM-Crash software and validated based on experimental results. A single-wheel tester along with a controlled soil bin at Urmia University, Iran is used to investigate the effect of a tyre's multi-pass and vertical load on the rolling resistance coefficient of an off-road tyre. In order to calculate the rolling resistance of Bekker model, a bevameter device is installed on a carriage moving on clayey-loam soil and a digital penetrometer is used for obtaining the output of Wismer-Luth model. Analysis of experimental data shows that rolling resistance coefficient increases as the vertical load increases and decreases with each pass of tyre. These results are used to compare and evaluate the above-mentioned methods. The results of this study will be used in further research on the interaction between a tyre and soil.

Developing an analytical model for prediction of tyre rolling resistance on moist soils

Developing an analytical model for prediction of tyre rolling resistance on moist soils

Determining Wheel Forces and Moments on Aircraft Landing Gear with a Dynamometer Sensor.

This paper describes airfield measurement of forces and moments that act on a landing gear wheel. For the measurement, a wheel force sensor was used. The sensor was designed and built based on strain gage technology and was embedded in the left landing gear wheel of a test aircraft. The sensor is capable of measuring simultaneously three perpendicular forces and three moments and sends data to a handheld device wirelessly. For the airfield tests, the sensor was installed on a PZL 104 Wilga 35A multipurpose aircraft. The aircraft was towed at a “marching man” speed and the measurements were performed at three driving modes: Free rolling, braking, and turning. The paper contains results obtained in the field measurements performed on a grassy runway of the Rzeszów Jasionka Aerodrome, Poland. Rolling resistance of aircraft tire, braking friction, as well as aligning moment were analyzed and discussed with respect to surface conditions.

Experimental verification of small diameter rollers utilization in construction of roller test stand in evaluation of energy loss due to rolling resistance

The vehicle‘s tire rolling resistance in road traffic plays a significant role mainly in the fields of fuel consumption and produced harmful emissions. It also plays a significant role in measuring on the roller test stands. An inspection measurement has a task of revealing such vehicles in traffic which have a negative influence on the environment and the traffic safety. It is necessary to develop constantly and complement the inspection tests so that it would be possible to keep pace with vehicle producers. Vehicles have been equipped with a number of electronic systems with a direct impact on the traffic safety and ecology at the present. The widely known DieselGate affair has shown the need for roller test stands not only for homologation measurements, but also to satisfy the inspection measurement needs. For the inspection tests, the overground roller testers with smaller rollers and therefore also with lower investment costs, seem to be very advantageous. The tire rolling resistance on the small diameter rollers (approximately 100 mm) will have considerable influence on the measurement (usually, the rollers with the diameter of 180–250 mm are used). The paper is focused on the tire rolling resistance (energy losses) analysis, considering the variously sized rollers (90–400 mm), vertical loads (2000–4000 N), speeds (10–70 km/h) and inflation pressures (1.9–3.2 bar). When using a small summer tire with the size of 165/70 R13 the resulting values showed that the tire inflation pressure have lower influence than 5% on the smaller rollers, vertical load showed similar effect. On the contrary, the roller size showed a significant influence. When using the 90 mm rollers, the energy loss attributable to rolling resistance doubled in comparison with the 400 mm rollers. In general, however, the small diameter of the rollers seems appropriate for a short-time inspection test cycles, which are currently modified in order to recognize vehicles in bad technical condition, namely at measuring of emissions production and braking effect.

Synergistic effect by high specific surface area carbon black as secondary filler in silica reinforced natural rubber tire tread compounds

The partial replacement of silica by high specific surface area and high structure Carbon Black (CB) N134 as secondary filler, keeping the same total filler content at 55 phr, shows a clear synergistic effect on overall performance. At low content of CB, i.e. in the range of 0–36 wt% of CB relative to total filler amount, the Payne effect and tan delta at both 0 °C and 60 °C change marginally, but thereafter gradually increase. Cure times are shortened in the presence of CB, facilitating an increase of productivity. Bound rubber content and mechanical properties show an optimum at 18 wt% of CB relative to total filler amount or at a ratio of silica/CB 45/10 phr. With regard to tire performance as indicated by the laboratory test results, the abrasion resistance, wet grip and ice traction can therefore be enhanced while maintaining the tire rolling resistance at the optimum level for this silica/CB ratio.

THE PAYNE EFFECT: PRIMARILY POLYMER-RELATED OR FILLER-RELATED PHENOMENON?

ABSTRACT The hysteretic softening at small dynamic strains (Payne effect)—related to the rolling resistance and viscoelastic losses of tires—was studied as a function of particle size, filler volume fraction, and temperature for carbon black (CB) reinforced uncrosslinked styrene–butadiene rubber (SBR) and a paste-like material composed of CB-filled paraffin oil. The low-strain limit for dynamic storage modulus was found to be remarkably similar for CB-filled oil and the CB-filled SBR. Small-angle X-ray scattering (SAXS) measurements on the simple composites and detailed data analysis confirmed that the aggregate structures and nature of filler branching/networking of carbon black were virtually identical within oil compared to the high molecular weight polymer matrix. The combined dynamic rheology and SAXS results provide clear evidence that the deformation-induced breaking (unjamming) of the filler network—characterized by filler–filler contacts that are percolated throughout the material—is the main cause for the Payne effect. However, the polymer matrix does play a secondary role as demonstrated by a reduction in Payne effect magnitude with increasing temperature for the CB-reinforced rubber, which was not observed to a significant extent for the oil–CB system.

Interaction mechanics of the wheel with the drum

Currently, the evaluation of tire rolling resistance as well as determination of the lateral withdrawal resistance rate is often performed on drum stands. In addition, test procedures of vehicles using drum stands of various design features (with a different number of drums, their location and drive type) are becoming more and more widespread. However, there are no works considering mechanics of interaction of an elastic wheel with a drum and determining kinematic and power characteristics. The aim of this research is to eliminate this gap. This work considers a general idea of rolling mechanics of the wheel on the drum, taking into the consideration frictional interaction of the “wheel-drum” pair, including determination of rolling resistance due to hysteresis losses inside the wheel’s material, tangential force, acting in the contact point, the moment on the wheel, the power of friction losses in the contact point, areas coordinate of adhesion and sliding in the contact point of the wheel with the drum, the relative speed loss (slippage) of the wheel, the interaction of the wheel with two drums.

Advisor Based Modeling of the Effect of Rolling Resistance on Regenerative Braking in All-Electric Passenger Cars

In this study, the effect of rolling resistance change on regenerative braking was examined in an all-electric passenger car according to UDDS (Urban Dynamometer Driving Schedule) drive cycle. As the tires with high rolling resistance absorb the kinetic energy of the vehicle more than tires with low rolling resistance, regenerative braking gain is reduced. In the all-electric car model created using the ADVISOR vehicle simulation program state of charge (SOC) was found to be 87.1% in the car with low rolling resistance tires and SOC was 85.6% in the car with high rolling resistance for 1 drive cycle. In addition, regeneration recovery was also investigated due to road slope. As the road slope increased, the amount of recovery was reduced for both tires. While a recovery of 735.01 kJ was achieved in a tire with low rolling resistance, in a tire with high rolling resistance a recovery of 670.85 kJ was achieved at a 5% road slope.

Non-regulatory parameters effect on consumption and emissions from a diesel-powered van over the WLTC

The effect of various non-regulatory parameters on a vehicle’s performance and emissions is investigated in this study, i.e. road grade, presence of crosswinds, surface wetness, tire pressure and use of the vehicle’s auxiliary systems. The vehicle under study is a diesel-powered turbocharged light commercial vehicle, running on the WLTC 3–2 cycle; comparison with the NEDC is also provided. The results derive from a computational code based on an engine-mapping approach applying experimentally derived correction coefficients accounting for transient operation. The engine code is coupled to a vehicle model that calculates the main longitudinal dynamic parameters (tire rolling resistance, aerodynamic performance, gearbox efficiency) on a fundamental basis. Soot and nitrogen monoxide are the examined pollutants, with fuel and energy consumption and CO2 emissions computed and discussed too. From the parameters examined, road grade was found to have the greatest impact on emissions (CO2: +116.8%, NO: +107.2%, Soot: +100.7%, for the maximum road grade examined of 8%), followed by wind speed (CO2: +38.9%, NO: +33.6%, Soot: +12%, for the maximum wind speed examined of 80 km/h). Auxiliary power demand can have a considerable effect, mostly on fuel consumption/CO2 emissions (+13.7% for maximum auxiliary power demand of 5000 W); the impact of tire inflation pressure and surface wetness is comparably smaller. Among the two driving cycles, the WLTC proved to be more ‘sensitive’ to road load changes, due to the broader speed range encompassed and its highly transient nature, compared to the softer NEDC.