Tire Research Articles

Уменьшение колееобразования широкозахватных дождевальных машин

During the process of irrigation, when moving sprinklers across the field, the wheels of the run-ning supports create a track. As the number of passes increases, so does the depth of the track. At the end of the irrigation season, it can reach 0.3-0.45 m, lead to slipping wheels and excessive wa-tering. The intensity of the process of rutting and reducing the coupling properties of the running systems of sprinkler machines is further increased in the presence of free, not absorbed water, caus-ing the formation of runoff on the track. The greatest depth of the track by the end of the season in the last undercarriages occurs due to the increase in the intensity of irrigation and the diameter of the drops of sprinklers located at the end of the pipeline. The choice of running systems should be made taking into account the characteristics of irrigated surfaces, rational ratios of span lengths, di-ameters of pipelines and sprinkler arrangement schemes. The aim of the study is to consider the im-pact of the irrigation process on the bearing properties of the soil and the formation of a track. The article presents theoretical dependences for determining the depth and width of the track for two-wheeled and three-wheeled undercarriages of wide-grip sprinkler machines. Field studies were con-ducted on “Kuban-LK1M” (Cascade) and “CASCADE” sprinkler machines. The article presents the dependence of the track depth on the number of the undercarriages with a soil bearing capacity of 110-125 kPa. The research made it possible to determine the approximate zones of application of wheel systems, depending on the bearing capacity of the soil. Analysis of the data shows that it is advisable to equip sprinklers with narrow pneumatic wheels on soils of increased strength. On soils with low bearing capacity and significant irrigation rates from 600 m3 / ha - wide-profile pneumatic tires 18-24; 23-26, 21.3-24 for “Kuban-LK1”, “Kuban-LK1M” (KASKAD), KASKAD with a pro-file width of 0.30-0.54 m, including the installation of wider tires at the end part of the machines. In addition, in conditions of low soil strength, it is possible to use tires on sprinklers with smaller profile widths than the recommended ones, but for reduced span lengths or a reduced diameter of the water pipeline.

Fracture Reduction in Steel Cord Manufacturing Process

Improve quality and productivity performance of a steel cord manufacturing system. The most importuned material of steel cord for tyre manufacturing process and that steel cord have good mechanical properties of high breaking strength, and low thermal coefficient of expansion as compared to nylon. Process for producing a Steel cord for pneumatic tires comprising a bunch of wires and core, the core of which consists of 3wire filaments arranged and bunched together in parallel. Then 6 wire (filament) on Core twisted and bunched in together. While processing on steel cord we faced wire fracture frequently like torsional fracture, power fracture, one filament fracture, entanglement fracture bad winding issue due to interrupted power and improper clamping of spool (wire Bobbin) and machine vibration. In this project have modified to Spool shaft on wire drawing machine. In this shaft, locking position and changed that shaft design. That shaft was reduced the spool wobbling while running on machine. In bunching machine, the circuit have power circuit-1, power circuit-2, control circuit, and commend circuit. The command and control circuits connected by uninterrupted power and power circuits connected with normal power (EB power). When power the cut-off, command and control circuit switchover to uninterrupted power, and it lead to smooth stop in machine. Thus, the changes have leads to reduce the fracture in cord manufacturing process.

Graph-analytical optimization of the transverse vertical cross-section of a contact zone between soil and an elastic wheeled mover

The intensification of agricultural production under modern conditions implies the use of super-powerful mobile technical means, which leads to an increase in the levels of technogenic impact on soil and, consequently, deteriorates its fertility. Therefore, the most acute issue related to current agricultural production is aimed at resolving the task on improving the operational indicators of wheeled running systems of mobile technical means. This necessitates an analytical study into the processes of soil deformation under the elastic motors of mobile wheeled agricultural machinery. We have proposed a procedure of the graph-analytical step-by-step modeling of the process of soil deformation under pneumatic tires of mobile agricultural equipment taking into consideration the changing shape of an elastic tire sheath. Using appropriate graphic models makes it possible to explore, in stages, the process of soil compaction inside the profile of the track it formed. It has been found that in the contact area «deformed soil – the surface of an elastic wheeled mover of the mobile vehicle» the highest level of compaction is observed in the soil layer, which is directly in contact with the elastic mover. The depth of the recompacted soil layer on the «track bottom» depends on the dimensions of a tire of the wheeled mover and does not exceed the value of 0.075 width of the tire. The highest soil compaction level is observed in the area directly adjacent to the gauge. It has been established that the most dangerous design of a pneumatic tire, in terms of soil overcompaction in the track, is the shape of an elastic tire sheath that is described by the curve of the Cassini oval with four points of inflection. We have outlined distinctive features of recommendations to determine the operational values of tire working pressure depending on specific physical-mechanical and agro-technological properties of soil and the character of performed technological operations

Ways to Improve the Durability of Pneumatic Tires

Current trends of functional improvement of pneumatic car tires are described in the article. As a rule, these are the structural features of a car wheel that allow getting the nearest service station after a tire damage. The airless tire design eliminates the damages specific for pneumatic tires. They have been used for construction vehicles and military vehicles exclusively. However, improving the durability of pneumatic tires is relevant. This is due to the increase of free speed. There are two ways to improve the durability of automobile tires. The first way is to use tire damping, thanks to the new material structure of the tire. The second way is to use thermoelectric cooling to reduce thermal effects on the tire.

Research the advantages and disadvantages of monorail transport

Drawing on the technical characteristics of the monorail system design in article describes the advantages and disadvantages of this transport. Was noted important design features which assure should be considered when designing monorail system. It was shown what due to the simplicity of its structure monorail system requires much less time for construction and has a more aesthetic appearance as opposed to elevated design of railway or light rail vehicles. Most monorail wagon equipped with pneumatic tire, unlike the rail bogie with the metal wheels, that to a great extent reflected during operation. Provided the comparative analysis of monorail system with more popular types of ground and underground transport. Based on the statistics data collected indicated the relevance of using the monorail system and positive aspects of the implementation this transport. A detailed analysis of the ecological situation points to the urgent need to reduce emissions in the transport sector, which will be facilitated by the transition to systems operated on electrical feeding. The research of road traffic accidents from 2018 on the example of Ukraine indicates a large number of accidents caused by the collisions and hit-and-run, which can be avoided by introduction the monorail transport, because the system is arranged in such a way trains do not intersect with other road traffic accidents. The full automation of movement provides a high level of security on this type of transport. Several important shortcomings of this transport were identified, the analysis of which the enabling reduce of negative influence and coordinate the working towards their removal in the future. The practical importance of article lies in the fact that the information obtained can be used in the implementation of monorail transport. The research on this subject has prospects in the direction of improving domestic infrastructure and enhance the quality of passenger traffic.

Traction and energy efficiency tests of oligomeric tires for category 3 tractors

The wheeled running gear of an agricultural tractor must have sufficient traction and coupling properties to ensure that the tractor fulfills its main function. The solution to these problems depends to a large extent on the search and implementation of measures for improving and developing new tire designs, which are the main element of the wheel drive that meets modern requirements. The developing of new pneumatic tires requires creating a new formulation of rubber and materials, the use of rubber-oligomeric compositions that allow implementing new, advanced technologies in the manufacture of tires. Currently, tires based on rubber-oligomeric compositions are being created. In particular, the Austrian company Lim developed a range of wide-section tires based on oligomers. As a result of tests of tires for class 3 tractors, it was determined that the oligomer tire 66×43.00-25 has the best traction and energy performance on all supporting foundations, compared to the serial tire 21.3R24.

타이어 저압감지를 위한 타이어 공진 주파수 추정

Indirect tire pressure monitoring system(i-TPMS) monitors the inflation pressures in pneumatic tires by using wheel speed signals acquired from the anti-lock braking system(ABS). Frequency analysis and wheel radius analysis are performed at the same time in order to monitor the tire pressures indirectly. The resonance frequency of the tire torsional vibration decreases as the tire pressure decreases. It is necessary to estimate the resonance frequency in order to detect a reduction in tire pressure. This paper discusses the method of estimating the resonance frequency with the rotational wheel speed signal. First, the toothed wheel error of the wheel speed sensor and the wheel speed corrected with the toothed wheel error are calculated from the wheel speed signals. The engine noise caused by the explosion in the four-stroke of engine is eliminated by the notch filter, which is designed by using the engine rotational speed. Finally, the resonance frequency is evaluated via model parameter estimation based on the autoregressive(AR) model. Vehicle tests have been conducted in order to evaluate the proposed estimation method of resonance frequency. The findings of the vehicle test have shown that the proposed method provides satisfactory performance for the warning indication of tire pressure loss.

Evaluation of drawbar performance of winter tyres for special purpose vehicles

Driving on ice is still a risky activity. Research has investigated the factors contributing to the friction mechanism and has reported experimental studies of pneumatic tyres on ice in order to develop models that predict tractive and braking performance on ice/snow. Therefore, developing testing methods to obtain relevant experimental data for the validation of models is equally important.There are agricultural and industrial vehicles which are also designed for pulling but there are no specific studies reporting experimental tests on traction force of such machines in snowy conditions. However, this issue is very topical, as demonstrated by the appearance on the market of winter tyres for such vehicles.This study presents a method for testing winter tyres in outdoor test facilities with a focus on traction performance. The conclusions will serve in future investigations as a concise knowledge source to develop improved testing facilities and tyre–ice interaction models, aiding the development of better tyre designs and improved vehicle safety systems.The functional tests hereafter described have been carried out with the aim of evaluating the possibility of measuring the influences of different technique solutions on the performance of certain 17.5 R25 sized industrial tyres.

Effect of Waste Type on Liquid Products Yields and Quality Obtained by Co-Liquefaction of Coal and Waste

The need to find alternative liquid fuels more environmental friendly and with a more secure supply, has led to the idea of studying the conversion of carbonaceous wastes, like plastics, used tyres and biomass into liquid products to be used as fuels or as raw materials for several industries. As coal liquefaction is a well-known process to produce liquid products, coal blended with used tyres and plastic wastes was co-liquefied. Coal impregnated with 1 % wt. of molybdenum was used in co-liquefaction tests blended with 50 % wt. of used tyres or with the main plastics present in municipal solid wastes: PE (polyethylene), PP (polypropylene), PS (polystyrene) and a mixture of these plastics. The results obtained showed that all wastes promoted coal liquefaction. However, liquids yield and quality improved with the presence of plastics, while more solids were obtained when used tyres were used. Coal blends with PS wastes led to the highest liquid yield (74 % wt.) and conversion (88 % wt.) The presence of PE favoured the formation of linear alkanes, while PS promoted the formation of more aromatic compounds, which is in agreement with these plastics initial molecular structure. Some co-liquefaction tests were done in presence of tetralin, a hydrogen donor solvent that promoted the formation of liquids. Tetralin allowed increasing liquids yields obtained with plastics to values higher than 90 % wt., while in co-liquefaction of coal with used tyres led to liquids yields around 77 % wt.

Method for experimental determination of the coefficients of stiffness and damping of rubber insulators

Rubber insulators are used in many dynamic systems to reduce the impact of vibrations. They are located in the mount system of the engine, gearbox, suspension, et cetera. Two of their characteristics are the dynamic coefficients of stiffness and damping. These characteristics are influenced by the frequency of vibration, the preload in the mounts and the hardness of the rubber. The characteristics of the rubber insulators in the suspension elements also influence the handling of the vehicle. In the work are investigated rubber insulators from different suspensions in the frequency range 70 - 220 Hz. This frequency range contains the resonant frequencies of the radial type pneumatic tyre due its interference with the road surface. The purpose of the work is to develop a method for obtaining the dynamic coefficients of stiffness and damping of the rubber insulators.

Расчётная оценка вибронагруженности автомобиля с колёсами повышенной безопасности при потере избыточного давления воздуха в пневматической шине

Расчётная оценка вибронагруженности автомобиля с колёсами повышенной безопасности при потере избыточного давления воздуха в пневматической шине

Prediction and Sound Quality Analysis of Tire Pattern Noise Based on System Identification by Utilizing an Optimal Adaptive Filter

Identifying the cause of vehicle noise is a basic requirement for the development of low-noise vehicles. The tire pattern noise depends on the tire itself and causes complex and unpredictable sounds. In pneumatic tire pattern design, the prediction technology of the tire pattern noise according to pattern shape design is important. The conventional method of predicting tire pattern noise is to simply scan the pattern shape of tire and to analyze its spectrum. However, this method has limitations because it does not consider the transfer function and precise mechanism of tire pattern noise. In this study, adaptive filter theory was applied to identify the transfer function between the grooves of patterns and measured acoustic data. To predict the waveform of an actual pattern noise in the time domain, the impulse response of this transfer function was convolved by the scanned pattern input of tires. The predicted waveform of pattern noise was validated with the waveforms of measured noise data. Finally, a sound quality index (SQI) of tire pattern noise was developed using the measured pattern noises and was applied to estimate the sound quality of pattern noise. Eventually, using the prediction method from this study, we hope to reduce the time and cost spent on tire pattern design and verification.

Recent advances and test processes in automotive and motorsports aerodynamic development

This article highlights the advances in the aerodynamic development and test processes of both road and motorsports cars over the last two decades, including explaining the main driving forces behind this evolution. The relentless and continuous drive to improve efficiency and correlation between computational fluid dynamics, real-time simulation, wind tunnel testing, and the track is explained. Key enabling technologies are described, such as: continuous motion systems; high-speed data acquisition systems; steel moving belt ground planes with under floor load cells; on-demand robotic particle image velocimetry; pneumatic model tyres with integral sidewall and contact patch deflection systems; driver simulators and rapid prototyped rake systems for track cars. Finally, as aerodynamicists attempt to simulate and test within ever more complex and realistic environments potential future directions and emerging trends are outlined, including gusts, aeroelasticity, adaptive cooling, and cornering.

Soft robot development: Air muscle for rehabilitation robotic application

Physiotherapy is a science which acts in the area of biomechanical and functional disorder, establishing diagnostics and supporting the locomotor system rehabilitation. These procedures require assistance of a physiotherapist, however they are insufficient for the country´s demand. Usually such procedures use devices with the newest technology, in order to enable recovery and avoid possible permanent trauma. In order to face this reality, we have committed to develop an air muscle, based on the McKibben´s model, with the purpose of proposing a new low-cost parallel robot to physiotherapy (Soft Robot) for the rehabilitation of patients with ankle injuries. This robot is responsible for moving three degrees of freedom platform, therefore acting directly in the rehabilitation of the patient through the execution of soft and accurate therapeutic movements that stimulate the recovery of operated tissues. First, it is build an air muscle that will be used as actuator in parallel platform. Then is raised a curve of behavior to shift versus pressure on proposed muscle. In conjunction with these data to actuator behavior is modelled and simulated the new parallel robot. This air muscle was build using a latex tube covered by a braided fibred mesh and fuelled by a pneumatic tire valve, therefore obtaining a nonlinear behavior of contraction to each pressure value admitted on muscle. By means of this prototype building purpose, we obtained satisfactory results, such as a contraction of 25% of the nominal length for pressures up to six bars. Considering such a result and the low cost involved building actuator as this one, the advantage in using this model is perceptible.

Comparative advantage and export performance of India’s rubber sector: an exploratory analysis

During the last 21 year period from 1996–2016, the total value of imports of rubber and rubber products grew at a rate of 17.66% compared to 14.18% growth rate in the value of exports. As a result of higher growth in imports and lower growth in exports, in the last 10 years, external trade in this segment had shown negative balance of trade consistently. In 2016–2017, the country had a negative balance of trade of US$ 414.76 million dollars. The broad objective of the present study is to identify products groups with comparative advantages in the global market. The study used methods such as Revealed Comparative Advantage, Revealed Symmetric Comparative Advantage and concentration ratio to analyse the comparative advantage of all the 17 rubber and rubber product groups (four digit level) under chapter 40 of the harmonised system nomenclature. Data from world integrated trade solution (WITS) during the period 1996–2016 are used for the analysis. Our results showed that despite a comparative disadvantage of the rubber sector at the aggregate level in the world market, the three product groups, viz, reclaimed rubber (HS 4003), inner tubes, of rubber (HS 4013), and hygienic or pharmaceutical articles (including teats) (HS 4014), exhibited comparative advantage consistently throughout the 21 year period. The two major product groups, viz., new pneumatic tyres of rubber (HS 4011) and other articles of vulcanised rubber other than hard rubber (HS 4016), which accounted for 68.68% of the total value of exports from the sector showed varied trends.

Oscillations Analysis of Front-Mounted Beet Topper Machine for Biomass Harvesting

The beet leaves and tops, which currently are excluded from the production process of sugar, could be an interesting opportunity for the production of renewable energy. Usually, the defoliators are joined with root collar remover machines, which are installed in front of the tractor. In working conditions on soils having natural roughness these front-mounted beet topper machines carried by tractors are affected by angular oscillations in a longitudinal-vertical plane that strongly affect the cutting uniformity. A theoretical study of these oscillations was carried out in this paper using Lagrange II kind equations, with the aim to assess the design and kinematic parameters of a front-mounted beet topper, corresponding to more stable and suitable movements in the longitudinal-vertical plane. A numerical simulation was then performed adopting the developed mathematical model. In order to improve the efficiency of this harvesting machine, a significant role is assumed by the soil preparation. In this work the stiffness and damping parameters of the feeler wheels pneumatic tires have been considered constant but further studies are in progress to assess their effective importance and influence for reducing the vibration of the front-mounted beet topper machine with the final aim to achieve a better machine design.

Application of the finite element method for calculating the thermal stress state of pneumatic tires

The processes of deformation of some of the widely used layered composite materials with elastomeric matrix, consisting of thin unidirectionally reinforced layers, or from alternating unidirectionally reinforced and isotropic layers are considered.The method of solving the problems of thermoelasticity of constructions from such materials is proposed, which is based on the finite element method.To form of resolving equalizations of finite element method for layered solid with initial tensions the super element method is considered. For every layer of finite element the stiffness matrix is built on the basis of incremental theory of deformation.The decision of task for the package of finite elements, that modeling the package of the layered construction, is taken to the decision of the system of equalizations in relation to moving of knots to the surfaces of package.On the second stage of decision of task moving of knots is calculated to the border of division of layers.The components of tensor of tensions are calculated for every layer taking into account the temperature of layer.The field of temperatures determined for all package on the basis decisions of task of heat conductivity.At the construction of matrix of heat conductivity an ideal thermal contact is assumed between layers.The function of internal heat source is calculated for every layer as average energy for the complete cycle of loading.The solution of the linked problem of thermoelasticity of a layered composite is obtained by the method of successive approximations.The offered method is applied for the decision of task about thermoelasticity deformation and dissipative warming-up of pneumatic tires. Pressure in a tire is considered as an initial load.Loading is attached to the axis of wheel creates additional deformations of tire. The process of tire roll is considered as cyclic deformation.Solution of the linked task of thermoelasticity is offered for over a large size tireDependences of temperature of dissipative warming up are got on frequency of vibrations and size of loading.The got results satisfactorily comport with experimental data.

Proper Radial Spokes of Non-Pneumatic Tire for Vertical Load Supporting by Finite Element Analysis

This research aimed to develop the 3D finite element model of non-pneumatic tire (NPT) for designing the proper radial spoke. The NPT was cut using waterjet cutting technique to prepare the appropriate test specimens. The hyperelastic constitutive models were used to model the deformation behavior of these NPT components. The rebar elements were used to model steel belt layers of the non-pneumatic tire, while the tying equation was used to tie the degree of freedom between belt layers and rubber elements. The NPT model was assigned to contact the rigid surface at the load of 14, 16, 18, 20 and 22 kN. The deformation analysis result of NPT model was compared with the physical experiment which obtained the average error of 9.29 %. The vertical stiffness of the NPT model was 810.66 N/mm; therefore the error was 6.81 % when it was compared to the experimental result. The validated NPT model was then used to search for the proper spoke thickness. The spoke thickness of 5 mm was found to be the proper thickness which given the identical vertical stiffness as the pneumatic tire.

Effects of Zinc-Free Processing Aids on Silica-Reinforced Tread Compounds for Green Tires

With the development of “green tires” in the tire industry, the conventional carbon black filler that is used in tread formulations is being replaced with silica. Generally, this requires the addition of a processing aid, containing zinc ion, which acts as a lubricant and dispersing agent. However, because zinc is a heavy metal, zinc-free processing aids (ZFAs) are required to satisfy worldwide environmental concerns. We present herein a series of catalytically synthesized ZFAs and evaluate the effects of replacing zinc ion-containing processing aids (ZCAs) on a silica tread formulation. Interestingly, replacing ZCA with ZFA in a two parts per hundred rubber (phr) by weight formulation improved both its tensile strength and elongation by as much as 31% and 20%, respectively. ZFA-rubber formulations also exhibited a twofold enhancement in fatigue properties over those of ZCA-rubber formulations. Furthermore, pneumatic tires were fabricated from our ZFA-rubber formulation and compared against tires containing ZCAs. The ZFA-rubber composite exhibited improved dry and wet braking and rolling resistance due to enhanced dispersion of silica in the rubber matrix. These results show that rubber composites prepared with ZFAs may be promising in tire engineering applications.

Anisotropic Combined Dry Friction in Problems of Pneumatics’ Dynamics

Traditionally used shimmy models assume vanishing slip at each point of a roadwheel contact spot, at the same time the observed instable wheel motion observed at unsteady rolling stages with significant sliding could not be described by traditional theories. Thus, a principally new model of the wheel shimmy is required to be consistent with such regimes. A new model of a rolling wheel accounting for the dry friction under the conditions of combined kinematics (i.e. simultaneous sliding, spinning and rolling) as well as for contact pressure distributions in pneumatic tires could become a background for various engineering methods of prediction of the shimmy appearing at unsteady rolling regimes. The proposed model of a pneumatic wheel’s motion is based on the improved dry friction theory accounting for the friction anisotropy; the Coulomb law is assumed for each contact spot’s point where the summary slip velocity is resulted by the simultaneous sliding and spinning, and the contact pressure could be obtained from the finite element simulation of quasistatic tire deforming. The theory of the coupled dry friction is improved by accounting for the anisotropy of the friction factor represented in a form of the second-rank tensor. The general formulation for the resultant vector of dry friction forces, dry friction torque and the rolling friction couple are obtained. The contact pressure for a typical tire is computed numerically, its polynomial interpolation is introduced, and the coefficients of the approximate model of the dry friction are obtained. The constructed model allows an efficient accounting for the dry friction effects on the rolling stability as well as the real contact pressure distribution; thus, it can be interpreted as the second approximation improving the model of the shimmy of quasi-rigid wheel.