Tire Research Articles

Rolling radii and moment arm of the wheel load for pneumatic tyres

Tractors and self-propelled harvesters are equipped with high volume pneumatic tyres with a low tyre inflation pressure. The contact patch can shift forwards or backwards in reference to the wheel centre as reaction on traction or brake forces because of the elastic tyre wall. Theoretical investigations – as necessary for modelling and simulation of dynamic vehicle behaviour – are complicated, since important tyre metrics cannot directly be measured based on the large deformations. Additionally, different definitions are often used. This is especially valid for the conversion of a drive torque into a traction force. In this context, the moment arm of the wheel load and the rolling radius of the tyre at zero slip condition are especially important. In contrast to the hitherto existing perception, the magnitude and position of the moment arm of the wheel load in reference to the wheel centre is dependent on traction and brake forces in addition to the motion resistance. The rolling radius of an elastic pneumatic tyre can be interpreted as radius of a fictitious rigid substitute wheel. This contribution emphasizes the outstanding importance of the rolling radius rdyn for all calculations on pneumatic tyres and the important roll of the variable moment arm of the wheel load for the moment compensation on the wheel.

Studies of the process of slipping a single car wheel

The article gives the analysis of known researches connected with studying of features of interaction an automobile wheel with loose soil. On the basis of the analysis of the state of study the question of modeling the wheel hitching, the relevance of the study of the wheel hitching process on loose ground is substantiated, the purpose and objectives of the research are formulated. The proposed scheme of wheel hitching with elastic tire on loose soil is proposed. The mathematical model and the results of modeling of a wheel with an elastic tire on a loose soil are presented. On the basis of comparison of the simulation results and the results of the experiment carried out earlier, the adequacy of the proposed mathematical model of the car wheels with elastic tire on loose soil has been proved. The amplitude and frequency characteristics of the oscillatory processes occurring in contact with the pneumatic bus with the ground and the nature of the influence of operational and constructive factors on these processes are determined. There is a hypothesis about the need to take into account the reactive forces acting on the wheel when hanging out due to the release of part of the soil from the zone of interaction of the tire tread with loose soil. A mathematical model is proposed for determining the reactive force acting on a wheel during hitching due to the release of part of the soil from the zone of interaction of the tread protector with a loose soil. The method of calculating the total traction effort on a wheel when it is tilted on loose soils is proposed, taking into account the reactive force arising as a result of the emission of part of the soil from the zone of interaction of the tread of the pneumatic tire with loose soil.

Seismic behavior of tire waste-sand mixtures for transportation infrastructure in cold regions

Seismic behavior of tire waste-sand mixtures for transportation infrastructure in cold regions

Investigation of Changes in the Structure and Adhesion Properties of the Surface of Tread Tire Rubber during Friction

Different types of tread rubbers used in pneumatic tires of different applications are studied in the present work. The influence of various rubbers used in manufacturing treads on the rubber surface structure and its tribological, mechanical, and adhesive properties is estimated. A study and comparative analysis of the results of tribological tests and microscopic studies are performed. Microscopy of the sample surfaces is performed both before and after the tribological tests. To visualize the surface, the methods of scanning electron microscopy (combined with elemental analysis) and scanning probe microscopy are used. The character of changes occurring on the surface during friction, which is simulated on a tribometer with a rubber ring–disk contact circuit, is studied using these microscopy methods. It is established that the worn surfaces of all elastomers under study have a close structure and typical surface microrelief, but have different adhesion and mechanical properties depending on the type of rubber used in the rubber base and the used fillers. It is noted that high values of the sliding-friction coefficient and similarity of the rubber surface structures prove that their abrasive wear mechanisms are identical. The performed tribological laboratory tests show that the friction coefficient of the tread rubbers at high temperatures decreases with an increase in the normal load, while the opposite trend is observed at low temperatures. It is established that the change in the relaxation properties of rubbers due to temperature changes greatly affects the dependence of the friction coefficient on the sliding speed, while the energy loss due to friction is maximal in the temperature range of 15–20°C.

A Calculational Aero-Acoustic Study of Spokes of an Isolated Nonpneumatic Tire

ABSTRACT With the progress of noise control of engines and the rise of new energy vehicles, the severity of tire noise has been increasingly highlighted. Recently, the nonpneumatic tire (NPT) has drawn attention because of its novel structure design that surpasses traditional tires in anti-explosion, maintenance-free, and low rolling resistance characteristics. However, with an open-side structure and violent air impact at the flexible spokes, an NPT emits greater aerodynamic noise than a pneumatic tire during high-speed rolling, which results in an adverse effect on the riding comfort of vehicles. The arrangement pattern of flexible spokes in an NPT plays an important role in the generation of aerodynamic noise. In this study, the aerodynamic flow around NPTs, which were in contact with the ground, rolled at a speed of 80 km/h, and had different arrangement patterns of spokes, was investigated using the Reynolds-Averaged Navier-Stokes method and Large-Eddy Simulation. Then, the far-field aerodynamic noise of different NPTs were calculated using Ffowcs Williams-Hawkings equations in the acoustic model of ANSYS-Fluent. The influence of spoke arrangements on the flow pattern and aerodynamic noise was analyzed. Based on the results, we propose an optimized design of spokes that can enhance the aero-acoustic performance of NPTs.

Study on tire‐ice traction using a combined neural network and secondary development finite element modeling method

SummaryResearch on tire‐ice traction theory is still in the basic stage, and there are large differences between the current theoretical calculation and engineering practice. Because testing of pneumatic tire performance on icy road is very expensive, and testing conditions are complex and variable, testing does not have higher repeatability. In this paper, a tire‐ice traction model is established based on a neural network and the finite‐element method. Through the model calculations, the traction characteristics of tires on ice can be well‐simulated. The method of combining the Levenberg‐Marquardt (LM) optimizing algorithm with the neural network is used to predict the friction between tires and ice. The attributive characteristics of tires based on testing results are then measured. A nonlinear finite‐element model of a 37 × 12.5R16.5 tire is established by adopting the Yeoh model of rubber and researching existing tire‐ice driving traction models. This tire‐ice finite‐element model can predict the changes of drawbar pull and torque when driving on icy roads, and two different tire working conditions, ie, straight line and turning, are taken into consideration simultaneously. The influence of slip ratio, speed, load on drawbar pull, and torque are also explored.

Experimental Investigation of the Tractive Performance of Pneumatic Tires on Ice

ABSTRACTThis investigation was motivated by the need for performance improvement of pneumatic tires in icy conditions. Under normal operation, the pneumatic tire is the only force-transmitting component between the terrain and the vehicle. Therefore, it is critical to grasp the understanding of the contact mechanics at the contact patch under various surfaces and operating conditions. This article aims to enhance the understanding of the tire-ice contact interaction through experimental studies of pneumatic tires traversing over smooth ice. An experimental design has been formulated that provides insight into the effect of operational parameters, specifically general tire tread type, slip ratio, normal load, inflation pressure, ice surface temperature, and traction performance. The temperature distribution in the contact patch is recorded using a novel method based on thermocouples embedded in the contact patch. The drawbar pull is also measured at different conditions of normal load, inflation pressure, and ice temperatures. The measurements were conducted using the Terramechanics Rig at the Advanced Vehicle Dynamics Laboratory. This indoor single-wheel equipment allows repeatable testing under well-controlled conditions. The data measured indicates that, with the appropriate tread design, the wheel is able to provide a higher drawbar pull on smooth ice. With an increase in ice surface temperature, a wet film is observed, which ultimately leads to a significant decrease in traction performance.

A review on pavement porous concrete using recycled waste materials

Pavements porous concrete is a noble structure design in the urban management development generally enabling water to be permeated within its structure. It has also capable in the same time tocater dynamic loading. During the technology development, the quality and quantity of waste materials have led to a waste disposal crisis. Using recycled materials (secondary) instead of virgin ones (primary) have reduced landfill pressure and extraction demanding. This study has reviewedthe waste materials (Recycled crushed glass (RCG), Steel slag, Steel fiber, Tires, Plastics, Recycled asphalt) used in the pavement porous concretes and report their respective mechanical, durability and permeability functions. Waste material usagein the partial cement replacement will cause the concrete production cost to be reduced; also, the concretes' mechanical features have slightly affected to eliminate the disposal waste materials defects and to use cement in Portland cement (PC) production. While the cement has been replaced by different industrial wastes, the compressive strength, flexural strength, split tensile strength and different PC permeability mixes have depended on the waste materials' type applied in PC production.

Wide-Base Tire-Building Process and Design Optimization Using Finite Element Analysis

ABSTRACT The wide-base tire is a relatively new design that originated to replace dual tires because of its potential for improved performance. However, during the construction process, the wide-base tire is more likely to experience tread deformation and uneven stress distribution. The goal of this study is to incorporate numeric techniques for the construction and design optimization of a wide-base, heavy vehicle, pneumatic tire. First, four conditions of the tire (385/55R22.5)–building process, including gluing of components on the main drum, gluing of components on the auxiliary drum, green tire, and finalizing the capsule vulcanizing machine, were simulated using finite element analysis. Second, to solve the difference in the tire's (435/50R19.5) material distribution between the real manufactured structure and the theoretical structure, the curved surface drum-building method and the parameters of the curved surface drum were determined by tire construction simulation. In this article, we present the method for collecting tire material, the measurement process, the analysis method, some general results, and statistics on the wide-base tire. Finally, validation of results of the simulation and measurement are given.

A GPU-based DEM-FEM computational framework for tire-sand interaction simulations

Recently, the discrete-finite element method (DEM-FEM) has proved to be an advanced technique for solid-particle interaction simulations. However, the low computational efficiency limits its applications to practical engineering problems. To achieve this end, this paper proposes a Graphics Processing Unit (GPU) based DEM-FEM, including contact detection, force calculation and information update, in the context of Compute Unified Device Architecture (CUDA) FORTRAN environment. Three numerical examples are performed to validate the efficiency, effectiveness and scalability of the developed method. On this basis, the GPU-based DEM-FEM is extended to a computing platform, and programmed into our in-house code PDFP-OVS for a typical solid-particle interaction problem, i.e. the running performance of a pneumatic tire on granular sand. Numerical result shows that a speedup of more than 15 can be achieved. The simulation results are found to be in good agreement with the experiment results in terms of the gross tractive effort, the drawbar pull and the running resistance, which validates the capacity of the platform in the travel performance analysis of the tire on granular sand.

MATHEMATICAL MODELLING AND CONCEPTUAL DESIGN OF NOVEL AUTOMATIC TYRE INFLATING SYSTEM

Pneumatic tyres release 10-15 kPa of air pressure every month requires regular topping up. Vehicles run with improper tyre pressure has been identified as one of the primary factors which leads into major and catastrophic road accidents due to puncture and explosion. The main aim of this research work is to design a pressure chamber for an Automatic Tyre Inflating System (ATIS) to replenish the pressure loss of a pneumatic tyre. In this paper, a model has been developed to mathematically derive the critical amount of required pressurized air for ATIS intermediary chamber design. Finite element analysis was also performed onto the designed chamber considering critical engineering elements to ensure safe operation with the pressure of 8449kPa. ATIS is postulated to automatically replenish adequate amount of pressurised air into the tyre when the tyre pressure drops 10% below the desired pressure. Thus, the air loss from the tyre can be continuously compensated for 12 months to have them running with safe pressure at all time without having human intervention to inflate them.

Analysis of the influence of the main factors on the characteristics of the elastic properties of elastic wheels of tractors

The work is devoted to the theoretical study of the elastic properties of tractor wheels and the analysis of the effect of air pressure in the tires and vertical loads on the wheel axles. According to the developed computer program, which allows to implement the method of calculating the characteristics of the elastic properties of tractor wheels with pneumatic tires proposed in this work, one-factor and complete factor computer experiments of two types were carried out. In computer experiments of the first type, the dependences of the elasticity coefficients of a number of elastic wheels were investigated when operating on the practically non-deformable basis of tractors MTZ-82 and MTZ-142 from the air pressure in the tires at different values of the vertical dynamic loads on the axes of the corresponding wheels of tractors. In computer experiments of the second type, the dependences of the elasticity coefficients and the normal deflection of the wheels with tires of different sizes from the air pressure in the tires at constant values of the vertical dynamic loads on the wheel axles were investigated. In computer experiments of both types, the deviations of the elastic properties of elastic wheels found by calculation are within the limits of the accuracy of measurements of the experimental data. Based on the results of computer experiments of the first type, regression equations were obtained reflecting the dependence of the elasticity coefficients of the elastic wheels studied on the air pressure in the tire for various values of the vertical dynamic loads on the wheel axes. According to the results of computer experiments of the second type, equations of regression of the coefficients of elasticity and normal deflection of wheels with tires of different sizes from air pressure in tires at constant values of vertical dynamic loads on the wheel axle are obtained. The high correlation values for these regression equations indicate the high importance of the relationships in the found correlation dependencies. The application of the proposed calculation method makes it possible to simplify and shorten the work on the choice of tires of optimum sizes to different tractors, taking into account the specific conditions of their operation. It was calculated that wheels with tires 18.4R38 are optimal on the rear axle of the MTZ-82 tractor.

Design and Performance Analysis of Vehicle Tyre Pattern Material Using Finite Element Analysis and ANSYS R16.2

As it stands now, rubber has been the main material used in the making of pneumatic vehicle tyres. Speed of the vehicle depends on many factors like steering geometry, inflation pressure, vehicle load, road temperature and environmental conditions. The main aim of this research is to develop a finite element approach and computationally evaluate the performance of a steady-state rolling tyre by changing the tyre tread patterns. The tyre normally composed of rubber and body-ply was investigated with regards to the effect of the inflation pressure. Tyre modeling using six different types of patterns was completed by using Creo parametric 3D modeling software and then the tyre was discretized into small elements through ANSYS R16.2. The rim area of the tyre was fixed and pressure was applied to the inside surface of the rim. Finite element analysis was completed by using ANSYS R16.2 and equivalent stress, contact stress and contact pressure were found out to identify the best tyre pattern. From the final results it was observed that, Pattern-I had good agreement of results as compared to other type of patterns which showed medium frictional stress and contact pressure.

Static stiffness characteristics of a new non-pneumatic tire with different hinge structure and distribution

To eliminate the potential risk factors of the conventional inflatable tire, a creative non-pneumatic tire named “ME-wheel” was developed. Based on the analysis of the bearing characteristics, four types of ME-wheel with varying hinge structures and distributions were designed. The static stiffness characteristics of these four ME-wheels were investigated by numerical simulations and experiments. The hyperelasticity and incompressibility of the rubber material were described by the Mooney–Rivlin model, and the multilayer rubber-cord composites were modeled by the rebar layer. The nonlinear finite element model of the ME-wheel, which included nonlinear property of the material, contact condition, and anisotropy of rubber-cord composites, was validated by the load characteristic test. Stiffness characteristic tests of these four types of ME-wheel and a pneumatic tire, including vertical, longitudinal, lateral, and torsional stiffness, were carried out using a low speed flatbed test bench. A sufficient comparison and analysis were made between the experimental data and simulation data. The research results provided some theoretical and technical verification on the performance and structural optimization of the ME-wheel.

Characteristics and model of the initial spray caused by an aircraft elastic tire rolling on the water-contaminated runway

The initial spray caused by a rolling aircraft elastic pneumatic tire is studied by Smoothed Particle Hydrodynamics method. The tire spray is divided into four types: bow wave, rooster tail, impact-generated side plume and wave-generated side plume. The distributions of the particles involved in the different types of spray in the initial unperturbed water film are studied, with the relationship between the momentum transfer, the relative position of water particles and the aircraft tire being proposed. The impact-generated side plume is caused by the direct impact of tire, while the wave-generated side plume is caused by the breakup of the wave developed by the tire. The particles involved in the wave-generated side plume all come from a parabolic region inside the strip of initial injected particles at a given time. The width of the parabolic region reduces with the increasing water depth. The strips and the kinematic characteristics of particles at any time are both similar. A model is developed to predict the direction and magnitude of the momentum transfer velocity in water film based on the similarity of the strips and the kinematic characteristics of the particles, which works well for the cases with small tire load and thick water film.

Towards a real-time pneumatic tire performance prediction using an advanced tire-ice interface model

Icy road conditions and tire operational parameters play a vital role in determining the overall performance of a vehicle. This study builds on prior work in the researchers’ group. The Advanced Tire-Ice Interface Model (ATIIM) simulates the temperature rise in the contact patch based on the measured pressure distribution and the thermal properties of the tread compound and of the ice surface. It has the capability to simulate the height of the thin water film created from the melted ice, to predict the tractive performance, and to estimate the viscous friction due to the water layer and the influence of braking operations, including the locked wheel condition. The experimental investigation included measuring the bulk temperature distribution in the contact patch to validate the temperature rise simulations of the ATIIM. As shown by the simulations and the test data, a rise in temperature was observed from the leading edge to the trailing edge of the contact patch. As the wheel load increases, the difference in temperature rise increases, as also reflected in the experimental study. When the temperature difference was significant, a thin water film was observed that resulted in a reduction of friction, which was simulated using the ATIIM.

Potential of three-dimensional footprint mold in investigating the effect of tractor tire contact volume changes on rolling resistance

In the present study a method is developed to estimate the three-dimensional (3D) footprint of pneumatic agricultural tires based on molding the tire footprint by liquid plaster and converting these molds to three-dimensional models using a 3D scanner. A Goodyear 12.4–28, 6 ply tractor drive tire was operated on a clay loam soil in a soil bin under three vertical loads, using three inflation pressures and three soil moisture contents at a constant forward speed of 0.45 ms-1. The results showed the rut depth and contact volume increased by increasing the vertical load and inflation pressure and soil moisture content. Contact volume was increased by increasing the vertical load, inflation pressure, and soil moisture content. A multiple regression model was presented with a coefficient of determination (R2) of 0.88 to predict the contact volume based on vertical load, inflation pressure, and soil moisture content. Finally, a univariate regression model was presented to predict the rolling resistance based on the contact volume with a relatively high R2 of 0.93. It was also found that in deformable surfaces, vertical penetration and soil contact volume are the main reasons for the increase in rolling resistance.

Magnetism of automotive wheels with pneumatic radial tires

This paper shows enhancement of knowledge about magnetic flux density of automotive wheels with radial pneumatic tires equipped with ferromagnetic belt made of tangled steel wires. The investigations were focused on the measurement of magnetic flux density vector (B) over tire’s tread using sensor ability to measure 3 Cartesian projections of B. The other aim of the article is to introduce the prototype of a measuring device as well as measurement technique the purpose of which is to obtain a single or a collection of so called magnetic profiles. Circumferential and crosswise to the tread magnetic profiles and scans over tread surface were presented and analyzed. Moreover, magnetic profile’s parameters were proposed in order to quantitatively characterize magnetic flux density changes in circumferential profiles. Usefulness of them was analyzed and discussed in the context of the measurement technique and the practical utilization. The results revealed that the magnetic flux density is not uniform over tire’s tread surface and the “magnetic surface” is not anisotropic but highly directional. What is more, there are preferred sensor’s locations and measurement directions. The Authors also pointed out some potential application of gained knowledge in domain of vehicle state measurement such as speed, distance and wheel slip.

Recycling of pneumatic scrap tyre into nano-crumb rubber by pulsed laser ablation in different pH media

Nano crumb rubber from scrap tyre is synthesized via 1064 nm pulsed Nd:YAG laser ablation in three different pH media i.e. DI-water (pH∼6.45), D-limonene (pH∼3.47) and NaOH solution (pH∼13.41). Field Emission Scanning Electron Microscope (FESEM) results show spherical morphology of crumb rubber with high degree of aggregation in DI-water and in D-limonene. However, dispersion of crumb rubbers is observed in NaOH solution. The smallest particles size is obtained in NaOH solution within the range of 10.9 nm – 74.3 nm. Energy-dispersive X-ray spectroscopy (EDX) and FTIR analysis confirmed the elements distribution and chemical bonding of rubber with DI-water, D-limonene and NaOH solution. The experimental findings shows that pulsed Nd:YAG laser ablation has potential for fabricating nano-crumb rubber in liquid media.

Coupled lateral-longitudinal vehicle dynamics and control design with three-dimensional state portraits

ABSTRACTThe dynamics of vehicles with pneumatic tyres are well-known to be non-holonomic, nonlinear, and subject to state bounds in order to remain on defined roadways. As such, it can be challenging to apply many of the tools typically used to analyse nonlinear dynamics and synthesise control strategies. Furthermore, the use of traditional stability analyses is often insufficient for vehicle control design since adherence to the roadway geometry implies a constrained space that dictates stricter conditions on the states than provable stability. A two-state phase portrait approach has been used to analyse vehicle dynamics and provides an illustrative view of the state trajectories at constant speed. This paper extends the phase portrait to three states to represent the nonlinear vehicle dynamics with steering and longitudinal tyre force inputs and consideration of the longitudinal vehicle dynamics. The concept of a fixed point in the phase plane is extended to a stable curve and example controllers are examined and synthesised using the three-dimensional vector space.