Tire Research Articles

Experimental research in automobile non-pneumatic tire force heterogeneity

Simplicity and high efficiency of a wheeled mover as a mechanism for converting rotational motion into a translatory one have conditioned its wide application in overland machines including motor vehicles. However a wheel with a non-pneumatic tyre (NPT) has a sufficient drawback lying in termination of a wheeled machine movement at the excess air pressure loss. Moreover, the loss of excess air pressure in a pneumatic tyre of traditional design at high speed of movement of a motor vehicle can lead to a traffic accident with heavy consequences. The stop of a motor vehicle to change a wheel on a heavy traffic roadway or roadside also poses a threat. These reasons determine the necessity of both well-known design improvements and search for the new wheeled mover design solutions to enhance a motor vehicle safety, the use of wheels with non-pneumatic tyres of elastic polymeric materials being one of them. Safety enhancement by means of non-pneumatic tyre use along with keeping the high performance of wheeled machine operational properties, is an important scientific and technical task that determines the research urgency.

Investigation on the static and dynamic behaviors of non-pneumatic tires with honeycomb spokes

Non-pneumatic tires (NPTs) have wide application prospects due to their advantages of no run-flat, no need of air pressure maintenance, and low rolling resistance. In this paper, the static and dynamic behaviors of NPTs with different honeycomb spokes were investigated. Based on the static behavior of three types of NPTs with the same cell wall thickness of honeycomb or the same reference load carrying capacity, it is shown that the maximum stresses in spokes and tread of a NPT are much lower than that of traditional pneumatic tires, but its load carrying capacity is higher than the latter. In comparison with the dynamic behavior of three types of NPTs designed with the same load carrying capacity, it is found that the stress level in spokes and tread under dynamic loading are higher than that under static loading. The rolling resistance of NPTs with the smallest cell expanding angle is lowest, which is due to the lowest mass and smallest deformation of honeycomb spokes. Taking all these factors into account, it is suggested that an optimal NPT in applications is one with a small cell expanding angle and wall thickness.

Development of an experimental research complex for determining parameters of interaction of a pneumatic tire with ground

When designing an all-wheel drive vehicle, an important task is to predict its traction properties and expected cross-country parameters. To solve such a problem it is necessary to have an adequate design model for interaction of a wheel propulsor and the deformable support base. The article deals with the problems associated with development of the test stand design, which allows to conduct fine experiments in the mechanical system “active wheel - ground” in a laboratory. The main tasks during the experiments on this stand are: simulation of the power and kinematic interaction of a real pneumatic tire (automobile wheel) with a deformable ground surface, the mechanical state of which can be varied; measurement of force and kinematic parameters of interaction in the system “tire - ground”; visualization of the process of unsteady interaction of the tire and the ground in the spot of their contact during acceleration, skidding and braking; development and creation of a measuring complex for assessing the physical and mechanical state of a ground massif. The authors reviewed the existing designs of similar stands and installations for determining the parameters of interaction of the wheel with the support base. Problems that need to be solved during the experiments are considered, namely: simulation of the power and kinematic interaction of a real pneumatic tire (automobile wheel) with a deformable ground surface, the mechanical state of which can be varied; measurement of force and kinematic parameters of interaction in the system “tire - ground”; development and creation of a measuring complex for assessing the physical and mechanical state of a ground massif. A set of measuring equipment is presented, with the help of which the physical and mechanical condition of ground conditions is evaluated during the tests. Investigations and experiments will make it possible to clarify the physics of the processes occurring in the spot of their contact, both from the tire side and from the ground.

Effect of surfactants on MWNT filled elastomer composites by latex mixing

The recent interest in advanced elastomer composites has led to an intensive study of nanomaterials, which exhibit a range of excellent chemical and physical properties. The advent of carbon nanotubes (CNTs) has created attractive opportunities for developing novel high performance nanomaterials. However, due to their strong van der Waals binding energies, CNTs have a tendency to aggregate, and so disaggregation and homogeneous dispersion remain critical challenges to the synthesis of successful elastomer composites. Here, we prepared a non‐covalently functionalized CNT suspension using a surfactant, without degrading the physical and chemical properties of the CNTs. Furthermore, the suspension was mixed with styrene butadiene rubber (SBR) latex to enhance the dispersion of the CNTs in the elastomer matrix. The eco‐friendly, cost‐effective, and scalable preparation method shows great potential for the production of elastomer nanocomposites. The successful homogenous dispersion of the MWNT in the SBR matrix resulted in composites with outstanding mechanical, thermal, and electrical properties at low loadings. Furthermore, to confirm their potential use in green (uncured) tyre applications, we employed them directly as fillers in the tread compounds of a pneumatic tyre, which exhibited enhanced abrasion, wet grip, and rolling resistance performance. This research opens new opportunities for preparing high performance elastomer composites for future industrial applications. POLYM. ENG. SCI., 58:1843–1848, 2018. © 2017 Society of Plastics Engineers

Modelling of the influence of tire characteristics on stability of motion with using vehicle at a scale

Modelling of the influence of tire characteristics on stability of motion with using vehicle at a scale

Draft of the MEPS and HEPS for Motorcycle Tyre in Thailand

The aim of study is to find suitable high energy efficiency standard (HEPS) and minimum energy efficiency standard (MEPS) of pneumatic tyres for motorcycles in Thailand with the engine displacement below 125 cc excluding tyres for racing and off-road purposes. About 17 million pneumatic tyres (90% domestic product) are sold annually. By using the multistage sampling method on 8 groups (142 models), total 61 models were chosen for testing the rolling resistance coefficient (RRC) following ISO 18164:2005. The results of F-test and t-test show that the section width, diameter, tread, brand, load index and highest velocity index of tyres have no effect on RRC. For suitable HEPS and MEPS, it is found that the RRC of tyres should not be exceeded 12 N/kN and 15.5 N/kN, respectively.

Exper-imental study of the characteristics of tractor pneumatic tires

One of the factors affecting the performance indicators of machine-tractor units is the perfection of the movers, among which the wheeled ones are dominant. Optimization of the parameters of the pneumatic tire as one of the elements of the oscillatory system and the main element of wheeled mover is one of the directions of increasing the efficiency of operation of machine-tractor units. The investigations were carried out with the aim of developing an effective technique for the experimental determination of the elastically damping, deformation, traction characteristics of tractor pneumatic tires, which makes it possible to correctly compare their various variants. In the course of experimental studies, the characteristics of pneumatic tires of size 16.9-30 radial (serial) model F-39 and diagonally parallel (experimental) structures were studied. Facility for testing pneumatic tires (tire tester) allows to perform the determination of the required indicators in real operating conditions. The developed technique of experimental researches allows to define necessary characteristics of pneumatic tires, to carry out comparisons of various variants. The deformation characteristics of pneumatic tires in the general case of their loading show that they experience longitudinal, torsional and radial deformations. The presence in 16.9R30 serial tire in contrast to the 16.9-30DP experimental tire of radial deformation directed from the wheel axis in the zone in front of the contact surface under the driving rolling mode causes large hysteresis losses in it. The experimental traction characteristics of pneumatic tires show a higher efficiency of the diagonal-parallel 16.9-30DP tire and its less slipping, which predetermines less abrasion of the soil with this type of tire. It has been established that the application of the experimental tires

Tires and vertical dynamics of wheeled mobile driving simulators

Wheeled Mobile Driving Simulators (WMDS) promise a high potential for urban traffic simulation. The tires generate the accelerations of WMDS and therefore are a key component of this simulator type. Hence, the choice of a proper tire concept is of high importance. Solid tires with compact dimensions and a high vertical stiffness are a possible alternative approach to conventional pneumatic tires. To assess the application potential of solid tires their characteristics are identified. The results show that high slip values and slip angles are necessary to reach the maximum friction coefficient of about 0.8 while their correlation is highly nonlinear. With the identified tire properties, the impact of the tires on energy consumption and motion control performance of WMDS is investigated. The solid tires show an increased energy consumption of about 4% compared to pneumatic tires in representative urban driving cycle simulations. Solid tires with their nonlinear characteristics lead to five times higher lateral acceleration errors in relation to pneumatic tires at accelerations of 5m/s2 during a horizontal eight maneuver. The vertical properties of both tires were identified to be not sufficient for the application of a WMDS solely sprung by tires on uneven grounds of common quality.

Design and analysis of non-pneumatic tyre

Non-Pneumatic Tyre (NPT) as the name suggests is a type of tyre that doesn't use air to support the load. Even though tyres made out of solid rubber exists, they don't have enough compliance and will not provide a supple ride if used in normal vehicles. The NPT discussed here consists of mainly three parts. A rigid hub, Deformable spokes that support vertical load, Reinforced shear band and tread made out of rubber which comes into contact with the surface. The properties of NPT like contact pressure, rolling resistance and load carrying capacity can be varied by altering the dimensions or materials used to manufacture NPT. Several researches are being carried out all over the globe to make NPT an alternative to the conventional pneumatic tyre. This paper consolidates an overview of the research works that were carried out to develop and improve NPT.

Modification of SSBR/BR with Trans-1,4-Polyisoprene Alloy Rubber for High Performance Passenger Car Radical Tire Tread Stock†

Modification of SSBR/BR with Trans-1,4-Polyisoprene Alloy Rubber for High Performance Passenger Car Radical Tire Tread Stock†

A Laminated Ring on Elastic Foundation Model and a Feedback Contact Algorithm for Tire-Road Contact Analysis

ABSTRACTThis article proposes (1) a two-dimensional tire model that extends the deformable ring on elastic foundation (REF) model by treating the ring as a laminated beam and (2) a feedback compensation approach to solve the tire-road contact problem as facilitated by the laminated REF model. The internal layer of the laminated ring is formulated using the Timoshenko beam theory that can also be easily regressed to an Euler beam. The external layer of the laminated ring is modeled as a circular beam that primarily takes into account the strain energy contributed by the tire tread in the transverse or radial direction. The elastic foundations are assumed to have a predeformation in the radial direction, which can model tire inflation pressure in pneumatic tires or foundation precompression/pretension for nonpneumatic tires. The analytical solution for the static deformation response of this laminated REF model due to an arbitrary external force is detailed first. Then, a feedback p-controller algorithm that penalizes geometry errors in the contact region is outlined as a unified approach that can be used to solve frictionless contact problems between a tire and arbitrary road profiles. The performances of the proposed model and algorithm are compared against those obtained from a detailed finite element analysis. Both flat surface and cleat contact responses are shown to illustrate the utility of this laminated REF model and the contact algorithm.

On the mechanical behavior of rubber springs for high speed rail vehicles

There are many engineering design problems that call for rubber components as the best solution. Vulcanized rubber has found its way into all sorts of devices, from the universal automobile pneumatic tire to the ubiquitous compliant bushing. Some high-speed rail vehicle suspensions make use of rubber, not only in the air spring itself, but also in the auxiliary spring. The mechanical characteristics of this component influence vehicle dynamics and, therefore, accurate spring models with which to conduct dynamic analysis would make for powerful design tools. Nevertheless, the mechanical behavior of rubber defies simple modeling on account of stress relaxation, creep, set, viscosity, internal friction, and nonlinear stress–strain relations. Despite the advances in the micromechanical understanding of these phenomena, as well as in the macroscopic modeling of rubber spring behavior, there is ample room for refinement, and this is precisely the goal of this paper. The mechanical behavior of a particular rubber spring for high speed rail vehicles has been characterized. The results reveal the necessary components of the model, and suggest the appropriate procedure for parameter extraction. Our model proposal consists of three elements in parallel: a nonlinear elastic spring; a “soft friction” element; and a Maxwell viscous component. The characterization procedure takes into account both stress relaxation and nonlinear elasticity. The proposed model accurately reproduces experimental results and may then be used with confidence in any type of numerical simulation. Nevertheless, for this statement to be true, the problem of “numerical softening” potentially induced by soft friction models should be resolved. The paper will show that a trailing moving average filter, seamlessly tied to the model, wipes out the softening effect.

Investigation on the use of waste tyre crumb rubber in concrete paving blocks

This paper investigates the utilization of waste tyre crumb rubber as the fine aggregate in precast concrete Paving block (PCPB). PCPB\'s are generally preferred for city roads, pedestrian crosswalk, parking lots and bus terminals. The main aim of this paper is to evaluate the mechanical properties of wet cast PCPB containing waste tyre crumb rubber. The mechanical properties were investigated using a density, compressive strength, split tensile strength and flexural strength tests at 7, 28 56 days according to the IS 15688:2006 and EN1338. The wet cast method was followed for producing PCPB samples. The fine aggregate (river sand) was replaced with waste tyre crumb in percentage of 5%, 10%, 15%, 20% and 25% by volume. All the test results were compared with the conventional PCPB (Without rubber). The test results indicate its feasibility for incorporating waste tyre crumb rubber in the production of PCPB by the wet cast method.

Morningness-Eveningness preferences and academic results: correlation between practical and theoretic discipline

Human beings organize most of their biological and behavioural activities according to a 24h period. The biological rhythms show differences between individuals and this variability is known as Circadian Typology (CT). Morning-types (M-types), are active early in the morning and soon reach their peak in mental and physical performance but tire early in the evening. Evening-types (E-types) find difficult to get up in the morning and require more time to reach their optimal status. Neither-types (N-types) show intermediate characteristics. Many studies indicate that age and sex may influence: morningness preference increases with age in adults, and women show a stronger trend toward morningness than men [1]. Student chronotype can represent one of the factors that may affect academic achievement. This study investigates whether the CT of the students is related to the final exam grades of two different disciplines, theoretic (Anatomy) and practical (Athletics). Anatomy and Athletics grades are good indicators of the overall academic performance of the undergraduates. The aim of this study was to evaluate whether the performance in Anatomy is correlated with Athletics for the three chronotypes. Participants were recruited among students of the School of Sport Science, University of Milan. They were 427 (294 males; 133 females). They completed the Morningness-Eveningness Questionnaire (MEQ): 44 students were classified as M-types, 280 as N-types and 103 as E-types. Individual performance in the final exams of Anatomy and Athletic were collected among them. M-type students achieved better results on final exams in Anatomy and Athletic than either E-type or N-type students. Moreover for M-types (R2= 0.187), it was observed a higher correlation concerning the results of the two disciplines than E-types (R2=0.0727) and N-types (R2=0.0236).

Experimental Study of Normal Contact Force Between a Rolling Pneumatic Tyre and a Single Asperity

This paper proposes a novel experimental test apparatus that permits direct measurements of tyre/asperity normal contact forces under rolling conditions without interfacial layer. A reduced-sized pneumatic tyre is set rolling on the exterior surface of a cylindrical test rig simulating a smooth road surface except a single asperity of simple geometric shape connected to an embedded force transducer. Distinct asperity geometries lead to similar shapes of force signal but different magnitudes whose relationships with the indentation have exponents close to those in classical analytical solutions. By analyzing the time signals of the contact force and their frequency contents for different rolling speeds, the quasi-static nature of the contact, commonly assumed in numerical models, is verified.

Calculation of the Tyre Curing Mould Cavity Shape Using FEM

This paper describes a modelling methodology that predicts a contour of a pneumatic tyre in the curing mould. Tyre contour is designed to be in the equilibrium shape. Such shape is described by a system of complex mathematical equations that has to be solved numerically. In this new approach a standard FEM software is employed to gain the shape without the need of dealing with these equations manually. The quality of the proposal of FEM approach was assessed by comparing the meridian to a verified solution for several tyre constructions and sizes. Selected results are presented to show the accuracy of the FE modelling procedure. Nowadays, most of the produced tyres are of a radial construction. Therefore, this paper deals only with radial tyres.

Analytical justification of the load capacity of pneumatic tires for tractors and agricultural machinery

Information on the parameters and operating modes of pneumatic tires for tractors and agricultural machinery is contained in state standards in the form of tables in digital form. The variety of types, sizes and designs of tires makes it difficult to determine the tire parameters taking into account conditions and operating modes. The information on the tire parameters is insufficient due to the lack of information about the contact area of the tire with a solid support surface. The article suggests the dependences of the load-carrying capacity of a tire on the generalized geometric parameter equal to the product of the outer diameter and width of the tire profile. The area of contact is an important parameter that affects the traction characteristics of the tractor, the depth of the track when driving on a plowed field and the resistance to movement of the tractor. New terms have been introduced - the theoretical and actual contact areas of the pneumatic tire. The dependence of the theoretical contact area on the generalized parameter equal to the product of the outer diameter and width of the tire profile for diagonal and radial tires is obtained. The cross-section method is used, by means of which the bus contact is cut off from the shell. In this case, the internal forces of the pneumatic tire framework are transformed into real external forces. The analytical dependence of the load capacity of a pneumatic tire is obtained, representing the algebraic sum of the lifting force of the shell and the vertical force of the frame. The universal formula is proposed for determining the actual contour area of the tire contact, in which the contact length and width are used. The values of the length and width of the contact, as well as the ratio of these quantities, are determined experimentally for different loads and pressures, the contact length being determined by the proposed analytical method.

Microplastics in the sediments of Terra Nova Bay (Ross Sea, Antarctica)

This is the first survey to investigate the occurrence and extent of plastic contamination in sediments collected in Terra Nova Bay (Ross Sea, Antarctica). Plastic debris extracted from 31 samples of sediments were counted, weighted and identified by Fourier-transform infrared spectroscopy (FT-IR). All sediment samples contained plastics: a total of 1661 items of debris (3.14g) were recorded from the 31 samples of sediment. Plastic particles in the samples ranged from 0.3 to 22mm in length. Fibres were the most frequent type of small plastics debris detected. In terms of abundance, microplastics (<5mm) accounted for 78.4% of debris. 9 polymer types were found: the most common material (94.13% by weight) was styrene-butadiene-styrene copolymer (SBS), widely used in pneumatic tires, etc. A decreasing concentration of plastic debris at increasing distances from the Mario Zucchelli Base was evidenced.

A hierarchical sequential ALE poromechanics model for tire‐soil‐water interaction on fluid‐infiltrated roads

SummaryThis paper introduces a hierarchical sequential arbitrary Lagrangian‐Eulerian (ALE) model for predicting the tire‐soil‐water interaction at finite deformations. Using the ALE framework, the interaction between a rolling pneumatic tire and the fluid‐infiltrated soil underneath will be captured numerically. The road is assumed to be a fully saturated two‐phase porous medium. The constitutive response of the tire and the solid skeleton of the porous medium is idealized as hyperelastic. Meanwhile, the interaction between tire, soil, and water will be simulated via a hierarchical operator‐split algorithm. A salient feature of the proposed framework is the steady state rolling framework. While the finite element mesh of the soil is fixed to a reference frame and moves with the tire, the solid and fluid constituents of the soil are flowing through the mesh in the ALE model according to the rolling speed of the tire. This treatment leads to an elegant and computationally efficient formulation to investigate the tire‐soil‐water interaction both close to the contact and in the far field. The presented ALE model for tire‐soil‐water interaction provides the essential basis for future applications, for example, to a path‐dependent frictional‐cohesive response of the consolidating soil and unsaturated soil, respectively. Copyright © 2017 John Wiley &amp; Sons, Ltd.

Design and Static Analysis of Airlesstyre to Reduce Deformation

In this work a model of an air less tire is introduced with a replacement of natural rubber materials in place of synthetic rubber in tread and polyester in place of nylon in carcass. The construction and material study of various types of air less tyre is done by comparing with pneumatic tire. A brief structural study has been done on spokes of airless tyre and analyzed by ANSYS software. Analysis has been carried out on various structures like honey comb, Spokes, triangular and diamond with an applied load of 1200N. Comparison study has been carried out among various structures with different materials and it study shows that tyre with diamond structure with synthetic materials gives less deformation compared to other structure