Tire Research Articles

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.

A Study of Silica Reinforced Rubber Composites with Eco-Friendly Processing Aids for Pneumatic Tires

The conventional carbon black filler, used in tread formulations, is being replaced with silica with the development of “green tires” in the tire industry. For this, the addition of a processing aid containing zinc ion was required as a dispersing agent and lubricant However, zink being a heavy metal, zinc-free processing aids (ZFAs) are needed to satisfy global environmental issues. Therefore, this study pre sented a series of catalytically synthesized ZFAs and studied the effects of replacing “Y” zinc-containing processing aids (ZCAs) in a silica tread compounds. Interestingly, the rubber composite replacing ZCAs with ZFAs in 2 phr (parts per hundred rubber) improved both its tensile strength and elongation by as much as 31% and 20%, respectively. In addition, the rubber compounds with ZFAs exhibited a two-fold i enhancement in fatigue properties over those with ZCAs. Furthermore, pneumatic tires were fabricated from the rubber compounds containing ZFAs and compared against tires with ZCAs. The tires containing ZFAs rubber composite showed enhanced 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 maybe promising in tire engineering applications.

Injuries After Oldtimer Accidents: Eighteen Years Experience in the Emergency Department of a Swiss University Hospital.

In recent decades, morbidity in road traffi c accidents has declined in Western Europe, mainly due to the enforcement of road safety policies and innovations in car engineering. In classic cars-so called "oldtimers" in Switzerland-these innovations in car engineering and often even seat belts are lacking, leading to a greater risk of morbidity after accidents. Thus, we reviewed our own series of victims of accidents with oldtimers who were admitted to our Level 1 Trauma Centre in Switzerland over the last 18 years. Within the 18-year study period and a total of 500,000 consultations, six documented oldtimer accidents were included in this case series. In three of the six oldtimer accidents and in all high-speed accidents, the car was overturned. In one case, the reason for this was unknown, in another a tire had suddenly burst and in a third this was triggered by evading an obstacle. Four reports contained information about a missing airbag and/or seat belt. Injuries included blunt abdominal injuries (laceration, mesenteric vessel injury), chest trauma (pneumothorax, rip fracture, scapula fracture), brain injury, and contusions. None of the patients died. In conclusion, oldtimer accidents are rare. However, pre-clinicians and clinicians treating patients after oldtimer car accidents should be aware of the specific risks-such as steering wheel injuries and consequences of trauma, i.e., extensive injuries to the head, chest and abdomen.

Study on the Thermal Decomposition of Plastic Residues

The use of plastics in the last decades significantly increased, thus plastic recycling processes are needed. Generally, mixtures of plastic materials are disposed together, hence the recovery of the polymeric material is difficult and expensive. Plastic residues could be valorized by thermal degradation processes aimed at recovering energy and/or valuable compounds for chemical industry. The main technologies used for this purpose are gasification and pyrolysis. The latter is a thermal degradation process that occurs in the absence of oxygen at moderate temperature (300-700°C), that could be used to recover the thermal power of biomasses. The reaction products are bio-oil, biogas and biochar. The aim of this work was to employ pyrolysis to energetically exploit different pure plastic materials, namely polyethylene terephthalate (PET), polyamide (Nylon-6), polyvinyl chloride (PVC) and polyurethane (PU), as well as a complex one such as end of life tyres (ELT). The reaction was performed at 400 °C for 90 min. The pyrolysis system was composed by a tubular quartz reactor heated with a tubular vertical oven. An integrated condenser was used to separate the liquid reaction products, while the incondensable gases were collected in a latex balloon. The reaction products were quantified gravimetrically and, in order to evaluate the functional groups, characterized by FTIR analysis. The reaction gases were also analyzed by GC-MS to determine the composition of this fraction. Results obtained from the different plastics were significantly different in terms of distribution and composition. In particular, PET produced a biogas consisting mainly of acetaldehyde and hydrocarbons, while the liquid fraction was composed of benzoic and terephthalic acids. Nylon-6 degraded producing a large amount of reaction gas (65 g/100g) composed of ammonia and light hydrocarbons, while the reaction liquid was mainly caprolactam. Around 53 g/100g of PVC reaction products were gaseous, mainly hydrochloric acid, followed by toluene and benzene at high concentrations. The degradation of PU produced a reaction gas, mainly composed by formic and acetic aldehydes. ELT pyrolysis was responsible for the production of high amounts of solid residue, while reaction gas and liquid seemed to be mainly constituted by hydrocarbons. In general, the study of pure plastic pyrolysis could help to better understand the thermal decomposition of complex plastic residues such as ELT.

Controlled traffic farming delivers better crop yield of winter bean as a result of improved root development

This paper reports on the continuation of a long–term experiment on the effects of alternative field traffic systems (STP–random traffic with standard tyre inflation pressure, LTP–random traffic with low tyre inflation pressure and CTF–controlled traffic farming) on soil conditions and crop development as influenced by different tillage depths (DEEP–250 mm, SHALLOW–100 mm and ZERO–tillage), in a randomised 3 x 3 factorial design in 4 replicates launched by Harper Adams University in Edgmond, UK, in 2011. The results from season 2017–2018 revealed that CTF delivered 8% higher crop yield of winter field bean (Vicia faba) cv. Tundracomparing to STP (p = 0.005), i.e. 4.13 vs 3.82 tonnes ha-1respectively (at 14% moisture content). The ZERO–tillage plots featured significantly lower plant establishment percentage comparing to shallow and deep tillage: 79% vs 83% and 83% respectively (p = 0.012). The research showed that roots traits differed significantly between contrasting traffic at depths greater than 50mm with p < 0.05of: tap root biomass, number of lateral roots, biomass of lateral roots as well as total root biomass (tap+lateral roots),delivering significantly greater values of those before mentioned parameters on CTF comparing to STP. Tap root length significantly differed between traffic systems (p < 0.001)giving significantly greater results on CTF comparing to LTP and STP (17.7, 13.4 and 12.6 mm respectively). Significant differences in tap root diameter were found only at the depth of 100 mm (p < 0.001) where again CTF delivered significantly higher root diameter than the remaining 2 traffic systems.In the shallow layer of soil (0–50 mm) a significant difference was found only for tap root biomass, for interactions, where STP ZERO gave significantly higher results than STP SHALLOW and CTF SHALLOW (1.430, 0.733 and 0.716 g respectively).