Tire Rolling Research Articles

Frictional Abrasion of Rubber: Transition from Sliding to Rolling

ABSTRACT To develop applicable friction and wear models on tire scale, reliable test data are required. Consequently, friction tests on block level are requested because the distribution of contact pressure as well as slip velocity is nearly homogeneous at the contact surface of the sliding rubber block. However, wear mechanism and energy intensity levels of sliding rubber blocks and rolling rubber wheels or tires differ significantly. Consequently, linking both sliding and rolling frictional abrasion is required; thus, a wear model for rubber material is introduced to consider both deformation slip and sliding. The model input for sliding friction and resulting wear rate is derived from linear friction test experiments using sliding rubber blocks at different loading. A unique and sophisticated re-mesh algorithm ensures proper mesh modification due to abrasion of the structure. A wear energy evolution approach is developed to consider low abrasion with small sliding distances to predict wear at rolling rubber wheels. The simulation framework of abrasion modeling is successfully validated using laboratory abrasion tests.

Mechanical properties analysis of non-pneumatic tire with gradient honeycomb structure

Non-pneumatic tires have the advantages of high safety and high load-carrying capacity, and have a broad potential for engineering applications. In this paper, the effects of different gradient angles on the static and dynamic performance of honeycomb spoke structure are studied. First of all, according to different gradient and gradient-free Non-Pneumatic Tires (NPTs) are designed and the corresponding finite element models of non-pneumatic tires are established respectively. Then, the static mechanical properties of NPTs are analyzed, including the bearing capacity of NPTs and the stress distribution of NPT components. Finally, the dynamic mechanical properties of gradient-free and gradient NPTs are simulated. The stress characteristics and rolling characteristics of the gradient to the key components of NPTs under dynamic load are analyzed. The results show that different gradients have effects on the radial stiffness of the tire, the maximum stress distribution position of spokes, tire rolling characteristics, and the stress characteristics of other parts of NPTs. The research results provide guidance for the structure design and optimization of non-pneumatic tires.

Stair-Climbing Wheeled Robot Based on Rotating Locomotion of Curved-Spoke Legs.

This study proposes a new wheel-leg mechanism concept and formulations for the kinematics and dynamics of a stair-climbing robot utilizing the rotating leg locomotion of curved spokes and rolling tires. The system consists of four motor-driven tires and four curved-spoke legs. The curved-spoke leg is semicircle-like and is used to climb stairs. Once the spoke leg rolls on the surface, it lifts and pulls the mating wheel toward the surface, owing to the kinematic constraint between the spoke and the wheel. Single-wheel climbing is a necessary condition for the stair climbing of whole robots equipped with front and rear axles. This study proposes the design requirements of a spoke leg for the success of single-wheel climbing in terms of kinematic inequality equations according to the scenario of single-wheel climbing. For a design configuration that enables single-wheel climbing, the required minimum friction coefficient for the static analysis of the stair-climbing wheeled robots is demon-strated. Thereafter, the stair-climbing ability is validated through the dynamic equations that enable the frictional slip of the tires, as well as the curved-spoke legs. Lastly, the results revealed that the rotating locomotion of the well-designed curved-spoke legs effectively enables the stair climbing of the whole robot.

Sound Source Localization at the Rolling Tire

A vehicle's tire rolling on pavement causes complex noise generating mechanisms which are a dominant sub-source of vehicle traffic noise. For the quantification of noise levels due to these tire-pavement interactions, standardized acoustic measurement methods exist, such as the Close-Proximity (CPX) method. These methods require microphones mounted near a rolling tire. However, they do not provide insight in the distribution and amplitudes of present sound sources. In this contribution, we aim at identifying the dominant sound sources of the rolling tire at discrete frequencies. This is accomplished by an inverse method combining microphone array measurements and Finite Element (FE) simulations. The microphone measurements were recorded on Austrian highways with a large measurement trailer built for research purposes. With the considered inverse method, not only the amplitudes of the dominant sound sources but also their phases can be identified. With these identified sources and a validated FE model of the measurement trailer, the sound pressure field within the trailer may be computed. The thereby calculated sound pressure is compared to measurements at the CPX microphone positions and other locations within the trailer.

On application of sound power radiation of rolling tyre measured using CPX-based methodology

The present paper provides a comprehensive account of sound power radiation measurement from a rolling tyre, utilising a methodology that employs an advanced PolyU Mark III Close-Proximity (CPX) trailer enclosure which is aimed to provide CPX measurement per relevant ISO stsandard with suppressed background noise within the interior. The interior walls and ceiling of the enclosure are equipped with diffuser panels, creating a reverberant environment suitable for sound power measurement using the comparison method. The optimal design of the enclosure, which minimizes acoustic resonance and ensures a uniform distribution of acoustic energy, is determined through extensive numerical simulations. During tyre/road sound power measurements, the spatially averaged sound pressure level (SPL) distributions within the enclosure are obtained with a reference sound source (RSS) of known sound power. The relationships between the RSS SWLs and the corresponding SPLs are established at all vehicle speeds. These relationships can then be utilised to deduce the total SWL, as well as its 1/3-octave spectrum, from the captured averaged SPL radiated by a tyre rolling at any vehicle speed. The effectiveness of the CPX-based sound power measurement are illustrated. Additionally, the potential of utilising the measured SWLs for predicting pass-by noise radiation to roadside is discussed.

Development of operational tire-suspension contact force analysis using frequency based substructuring

With increase of EVs, we need to improve road noise performance as background noise caused by engines are reduced. On the other hand, to predict road noise performance, it is necessary to consider both tire and vehicle vibration characteristics, and various prediction techniques have been reported. Frequency based substructuring method (FBS) can predict the road noise performance by combining vibration characteristics of components of a vehicle, and is effective for reducing the development cost because it can clarify the development goals of both OEM and suppliers. With this regard, FBS is very useful for implementing MBD in the development of vibration noise. In this paper, for the road noise up to 500 Hz, in which structure-borne noise is the main source, we calculate the coupled vibration characteristics consisting of two subsystems: a tire (including a rigid wheel) and a suspension, by calculating in the rolling state for each subsystem by simulation and combined them by FBS. To evaluate the method, we compared the results with the vibration characteristics of the entire system in the rolling state. In particular, we calculated the transfer function of a tire in a rolling state to take the effect of tire rolling into account .

Accounting for the vehicle influence on tyre noise through acoustic simulation based on equivalent monopole sources

Road traffic noise poses a risk to human health and amongst the different noise sources, tyre-road interaction plays a fundamental role. Due to the regulations introduced to limit noise levels, tyre manufacturers are committed to design acoustically optimized tyres. In this context, a numerical-experimental approach for including vehicle influence on tyre noise has been investigated. As a first step, equivalent monopole sources are identified based on the measurements of the radiated sound field of a rolling tyre in a semi-anechoic chamber. In a second step, the same sound sources are then employed for the prediction of sound propagation when tyres are mounted on a vehicle, which is included in the acoustic simulation. Finally, a validation against indoor experimental measurements is performed, yielding promising results.

AERODYNAMIC AND ROLLING RESISTANCES OF HEAVY DUTY VEHICLE. SIMULATION OF ENERGY CONSUMPTION

The main objective of the work was to develop a comprehensive model of energy consumption simulation of heavy duty vehicles using the VECTO simulation tool. The research issue was the impact of aerodynamic drag and rolling resistance on fuel consumption and emissions under various driving conditions described in four driving cycles: Urban Delivery, Regional Delivery, Urban, and Suburban. Each cycle differed in driving time, distance and average speed to represent different operational scenarios. The methodology involved defining vehicle parameters such as weight, aerodynamic coefficients and tyre rolling resistance. The main findings show that the impact of both aerodynamic drag and rolling resistance on fuel consumption can be efficiently modelled. It has been proven that the proposed modifications to aerodynamic drag and rolling resistance can reduce fuel consumption by more than 8%. The lowest fuel consumption was achieved in the Regional Delivery cycle, while the Urban cycle had the highest fuel consumption due to frequent vehicle stops. The results show that optimization of vehicle design and its performance can significantly improve energy efficiency and reduce emissions. A computational modelling tool such as VECTO can contribute to sustainable transport solutions and improve the efficiency of heavy duty vehicle.

Application of wet carbon black masterbatch in green mining radial tires

AbstractIn the context of environmental protection and energy consumption reduction, reducing the rolling resistance of mining machinery tires is one of the important methods to achieve the goal of green mining. This study probes the effects of wet mixing with a wet carbon black masterbatch on the rolling resistance and grounding performance of wide‐body vehicle tire treads by investigating the cross‐linking structure, rubber–filler (R–F) interaction force, and physicomechanical properties of the wet mixing rubber compounded with a wet carbon black masterbatch. The results indicate decreases in the maximum torque‐minimum torque difference, cross‐link density, and R–F interaction of the wet mixing rubber and increased filler–filler (F–F) interaction and carbon black dispersion. Meanwhile, the tensile elongation of the wet mixing rubber increases, its DIN abrasion property improves, and its Tanδ decreases at 60°C. A numerical method to estimate tire steady‐state rolling resistance is also developed. Finite element simulation analysis reveals that the steady‐state rolling resistance of the wet mixing rubber is reduced by 7.04% at 100% standard load, and its grounding performance is enhanced. By proposing a method to reduce the rolling resistance of tires, this study also provides a reference for the development of wide‐body vehicle tires.Highlights Explored the filler interaction of wet mixing rubber. Explained the low energy loss of wet mixing rubber. Proposed a new finite element method for calculating tire rolling resistance.

GRAPHENE AS AN ANTIOXIDANT AND ANTIOZONANT IN TIRE SIDEWALL COMPOUNDS

ABSTRACT Tire sidewalls have an important function in achieving optimized tire performance. The sidewall compound must show good abrasion resistance, aging resistance, and tear strength; low hysteresis and minimal contribution to whole tire rolling resistance; and good adhesion to adjacent components in the tire. In addition, in both the original equipment market and the premium performance market, appearance is of considerable importance. The current system of waxes, antioxidants, and phenyl diamine antiozonants is very effective in meeting the need of the tire end user. However, recent concerns centered on the environmental impact of N′-phenyl-p-phenylenediamine, specifically N-(1,3-dimetylbutyl)-N′-phenyl-p-phenylenediamine, and staining and discoloration of the tire sidewall surface raise issues that should be addressed. Specialized grades of graphene can offer a mechanism by which tire appearance and environmental concerns can be overcome. Pristine graphene can improve compound resistance of ozonolysis and oxidation by replacing the current antiozonants and antioxidants used in tire compounds; improve tire sidewall appearance; and improve tire sidewall resistance to scuffing, abrasion, and tearing.

Thermo-micromechanical finite element modelling of tyre–pavement interaction under UAE environmental conditions

ABSTRACT This work presents a finite element model of the thermo-mechanical behaviour of tyre–pavement interaction, focusing on the effects of temperature variations in the UAE on skid resistance under various tyre operating conditions. The pavement is modelled as multiple layers to account for the stiffness contribution of each layer. The top asphalt layer is modelled at a microscale level to consider its various constituents such as air voids, aggregates and binder. Moreover, the model accounts for the viscoelastic properties of tyre and pavement, considering their dependence on time and temperature. The finite element simulations of a rolling tyre over the pavement have been carried out under different tyre operating conditions and various temperature cases reflecting the winter, spring, and summer seasons in the UAE. The simulation results show that the maximum level of skid resistance occurs during the winter season and thereafter drops by a significant amount during the summer. This research provides good insights about the seasonal variation of skid resistance in the UAE, which enhances road safety.

An adapted two-step approach to simulate nonlinear vibrations of patterned tires rolling on a smooth surface

The tire/road noise is one of the major problems facing the tire industry due to the nuisance felt by the vehicle's driver and passengers. Moreover, it is expected in the coming years that this sound nuisance will be one of the main sources of vehicle noise due to the transition from combustion engine driven vehicles to electric vehicles. Tire manufacturers have therefore refined the design of their tire structures to find technological solutions to reduce traffic noise. Tire/road noise is also generated by various mechanisms which depend on different parameters such as the properties of the tire, road texture and driving conditions. This noise is partly caused by the acoustic radiation induced by the tire vibrations due to contacts with the road. The simulation and analysis of the tire's vibrations remains a challenge for the tire industry. Indeed, the simulation of the full dynamic response of a rolling patterned tire requires not only taking onto account various nonlinearities but also the multi-scale nature of the generated dynamic response. Contrary to a straightforward strategy that consists in using a time integrator to predict the multi-scale dynamic response, the strategy proposed in this study is based on a two-step approach to separate the dynamics occurring at different scales. The mathematical formulation of the proposed method is detailed as are the different modeling choices to simulate tire rolling under imposed load. The sensitivity of the tire's vibrations response is analyzed under different rolling conditions and with respect to certain key tire tread pattern parameters.

Comparison of Tire Rolling Resistance Measuring Methods for Different Surfaces

The rolling resistance of car tires is one of the most important parameters characterizing tires today. This resistance has a very significant contribution to the energy consumption of wheeled vehicles. The climate crisis has forced tire and car manufacturers to place great emphasis on the environmental impact of their products. Paradoxically, the development of electric vehicles has led to an even greater importance of rolling resistance, because in electric vehicles, a large part of the influence of grade resistance and inertial resistance has been eliminated due to re-generative braking, which resulted in rolling resistance and air resistance remain as the most important factors. What is more, electric and hybrid vehicles are usually heavier, so the rolling resistance is increased accordingly. To optimize tires for rolling resistance, representative test methods must exist. Unfortunately, the current standards for measuring rolling resistance assume that tests are carried out in conditions that are far from real road conditions. This article compares the results of rolling resistance tests conducted in road conditions with the results of laboratory tests conducted on roadwheel facilities. The overview of results shows that the results of tests conducted in accordance with ISO and SAE standards on steel drums are very poorly correlated with more objective results of road tests. Significant differences occur both in the Coefficients of Rolling Resistance (CRR) and in the tire ranking. Only covering the drums with replicas of road surfaces leads to a significant improvement in the results obtained. For investigations of rolling resistance in non-steady-state conditions, the flat track testing machine (TTF), equipped with asphalt cassettes, is shown to provide measurement data in agreement with the road test data.

Intelligent Tire Prototype in Longitudinal Slip Operating Conditions.

With the recent advances in autonomous vehicles, there is an increasing need for sensors that can help monitor tire-road conditions and the forces that are applied to the tire. The footprint area of a tire that makes direct contact with the road surface, known as the contact patch, is a key parameter for determining a vehicle's effectiveness in accelerating, braking, and steering at various velocities. Road unevenness from features such as potholes and cracks results in large fluctuations in the contact patch surface area. Such conditions can eventually require the driver to perform driving maneuvers unorthodox to normal traffic patterns, such as excessive pedal depressions or large steering inputs, which can escalate to hazards such as the loss of control or impact. The integration of sensors into the inner liner of a tire has proven to be a promising method for extracting real-time tire-to-road contact patch interface data. In this research, a tire model is developed using Abaqus/CAE and analyzed using Abaqus/Explicit to study the nonlinear behavior of a rolling tire. Strain variations are investigated at the contact patch in three major longitudinal slip driving scenarios, including acceleration, braking, and free-rolling. Multiple vertical loading conditions on the tire are applied and studied. An intelligent tire prototype called KU-iTire is developed and tested to validate the strain results obtained from the simulations. Similar operating and loading conditions are applied to the physical prototype and the simulation model such that valid comparisons can be made. The experimental investigation focuses on the effectiveness of providing usable and reliable tire-to-road contact patch strain variation data under several longitudinal slip operating conditions. In this research, a correlation between FEA and experimental testing was observed between strain shape for free-rolling, acceleration, and braking conditions. A relationship between peak longitudinal strain and vertical load in free-rolling driving conditions was also observed and a correlation was observed between FEA and physical testing.

Analysis of Off-Road Tire Cornering Characteristics by Using Advanced Analytical Techniques

ABSTRACT This paper focuses on analysis of the cornering characteristics of an off-road truck tire running under several operating conditions over different soils. The finite element analysis (FEA) method is used to model the Goodyear RHD 315/80R22.5 truck tire, and the smoothed-particle hydrodynamics (SPH) method is used to model the soil. The goal of this research is to provide a virtual testing environment in Pam-Crash software as an alternative to actual tests for FEA and SPH analyses of rolling tire interactions on deformable terrains. The study on the effects of different operating parameters on the cornering performance combined with the sensitivity study can be of interest to tire engineers or vehicle engineers because they provide insight into the design and real-time behavior of a vehicle. Tire and soil models are validated using experimental data and published measurements, showing good agreement. The tire–soil interaction is investigated under different tire conditions, such as longitudinal speed, inflation pressure, vertical load, and slip angle, and under various soil characteristics, such as cohesion, internal friction angle, and rut depth. Cornering force, self-aligning moment, and overturning moment are studied as the fundamental cornering characteristics that affect truck lateral stability and control. Owing to the excessive computational demands posed by the FEA-SPH tire–soil models, we propose unique mathematical relationships for estimating the cornering characteristics of free-rolling as well as driven truck tires in an efficient manner. The genetic algorithm (GA) technique is used to develop relationships between the cornering parameters and operating conditions. We conclude that the identified mathematical relationships could provide very good estimations of the cornering characteristics under a broad range of operating conditions and soils. The GA equations will ultimately be implemented into a full vehicle model to evaluate the full vehicle performance.

Comparative analysis of FEM tire-soft snow interaction and theoretical model based on Bekker’s coefficients

Tire-deformable terrain interaction is a complex phenomenon that has proven difficult to characterize accurately and comprehensively using numerical models. While researchers have attempted to develop various numerical models to estimate tire behavior on deformable terrain, the most accurate models to date rely on empirical data and are only applicable to specific rolling conditions. In this research paper, a comparison between theoretical mechanics and a finite element method (FEM) model of a rigid tire rolling on a layer of soft snow is presented. The goal is to compare the data obtained from the FEM tire-soft snow interaction analysis with the data generated by a theoretical numerical model. The FEM snow model is developed using the Drucker-Prager cap material model while the tire is assumed rigid. The assumption of the rigid tire can provide reasonably accurate results in the case of the soft snow interaction model. The theoretical pressure-sinkage coefficients of the Bekker equation (kc, kϕ and n) for soft snow are calculated by simulating vertical penetration tests in the FEM snow model. The results of the pressure distribution and rolling resistance due to compaction obtained by the FEM and the theoretical model results are then compared.

The modified in-plane rigid-elastic-coupled tire modal model: dynamic response to short wavelength road profiles

The 400-degree-of-freedom deformed in-plane rigid-elastic-coupled tire model was enhanced by incorporating the vertical movement of the wheel as a rigid body. This refined model was then utilised to build the tire modal model. The tire modal model was developed to derive the transfer function (TF) covering a range of 0–300 Hz, which connects road irregularities as input to the contact patch and the wheel's vertical motion as output. The TF was operated under a quasi-static condition to obtain the tire's enveloping characteristics rolling over short wavelength obstacles as a direct function of vertical wheel displacement under varying contact patch length constraints. The tire modal model was combined with the quarter car model to analyse the vehicle's response when passing through short wavelength obstacles and random road profiles. This analysis was performed under varying load conditions represented by the contact patch length. The model and methodology demonstrated their effectiveness in handling rolling tires over short-wavelength obstacles and random road profiles.

Metamodeling on uncertainty quantification in the behavior of the tire/road interaction of vehicles

In recent years, the automotive industry has been developing applied research to meet customer’s needs; considering safety, vehicle comfort and energetic efficiency. In particular, automotive tires have a prominent position in this research area, ensuring good vehicle handling, comfort and safety. In the vehicle dynamics performance, excellent gripping and reduced rolling resistance in the tires are crucial to maximize the energetic efficiency in a reliable way. However, to ensure such a level of reliability in vehicle operation, the inherent uncertainties of tires, as well as other factors subject to variability must be taken into account in the vehicle design. In this way, the present paper analyzes in detail the effect of variations in some parameters such as ambient temperature, ground conditions, vertical load, speed and tire inflation on the analysis of vehicle dynamics. A Metamodeling approach associated with the Monte Carlo Simulation was employed to develop the mathematical models to analyze the effect of uncertain parameters on the tire rolling resistance; traction, centripetal and lateral forces, using experimental data from the literature, in the longitudinal and lateral vehicle dynamics. Therefore, the present research brings as an innovation an integrated approach to the input parameters of the system with the rolling resistance through the developed metamodels. There was a substantial variability of up to 15% both up and down in the Maximum Traction Force of a vehicle in response to variations in the vehicle’s weight and the coefficient of tire rolling resistance. In contrast, the Lateral Force exhibited a greater variability, with a 25 downward and 10% upward variation associated with the weight and friction coefficient variability of the vehicle. Further investigations into the sensitivity analysis highlight the significant influence of the friction coefficient and temperature on the Traction Forces of the vehicle.

Assessment of the increase in operating fuel consumption of a KAMAZ long-haul road train in winter conditions

The performance indicators of wheeled vehicles — fuel consumption and speed of cargo delivery — have always been and remain one of the key factors ensuring their high efficiency for the consumer. To increase efficiency, specialists of KAMAZ PJSC have developed and are producing new generation vehicles of the fifth environmental class with improved fuel efficiency. Practice shows that owners of new cars do not have basic fuel consumption standards and various surcharges for them. For this reason, they are forced to turn to the manufacturer, and the manufacturer, in accordance with current legislation, does not have the right to develop standards. Anticipating possible requests from owners of new cars, the authors tried to present in a systematic form the factors affecting fuel consumption and assess its possible increase in winter conditions for the KAMAZ long-haul road train. Keywords wheeled vehicle, road train, operational fuel consumption, operating conditions, tire rolling resistance, aerodynamic resistance

A semi-physical thermodynamic transient rolling resistance model with nonlinear viscoelasticity

Rolling resistance dictates a large part of the energy consumption of trucks. Therefore, it is necessary to have a sound understanding of the parameters affecting rolling resistance. This article proposes a semi-physical thermodynamic tyre rolling resistance model, which captures the essential properties of rolling resistance, such as transient changes due to temperature effects and the strain-amplitude dependency of the viscous properties. In addition, the model includes cooling effects from the surroundings. Both tyre temperature and rolling resistance are obtained simultaneously in the simulation model for each time step. The nonlinear viscoelasticity in rubber is modelled using the Bergström–Boyce model, where the viscous creep function is scaled with temperature changes. The cooling of the tyre is considered with both convective and radiative cooling. Moreover, the article explains different material parameters and their physical meaning. Additionally, examples of how the model could be used in parameter studies are presented.