Tire Research Articles

COMPUTATIONAL AND EXPERIMENTAL STUDIES OF VIBRATION PROTECTION PROPERTIES OF THE PNEUMATIC WHEEL OF THE MTZ-82 "BELARUS" TRACTOR WITH EXTERNAL SPRING-HYDRAULIC MINI SUSPENSION

BACKGROUND: Currently used in various sectors of the national economy, numerous wheeled non-suspension vehicles on pneumatic tires have a low level of vibration protection of the frame and limited cross-country ability. Therefore, the development and study of the design characteristics of a pneumatic wheel with increased elastic-damping properties and cross-country ability is an urgent technical problem. AIMS: The purpose of the work is to develop a design and study the vibration-protective properties of a pneumatic wheel with an external spring-hydraulic mini-suspension to improve the smoothness and cross-country ability of large non-suspension vehicles. METHODS: A description of the design of a wheel with mini-suspension and support roller is presented. The wheel modeling was carried out in the PascalABC program, which takes into account the nonlinearity of the total force of the pneumatic tire and the spring-hydraulic mini-suspension, which is installed parallel to the tire at an angle to the vertical axis of the wheel. The test methodology consisted of conducting comparative free and forced vibrations of the rear pneumatic wheel from the MTZ-82 "BELARUS" tractor with a 400-965/15.5-38 tire, which operated without and with mini-suspension at a vertical load of 0.6 tons and different excess pressures in the tire. RESULTS: From the results of computational and experimental studies it follows that when the tire is radially compressed by 75 mm, the excess pressure inside the pneumatic wheel almost does not change, and when the pressure in the tire decreases from 1.6 to 0.4 bar, the resonant vibration frequency of the standard wheel axle decreases by 25%, while the dynamic coefficient remains unacceptably high (more than 5), leading to separation of the tire from the supporting surface. Installing a mini-suspension parallel to the wheel in the form of a spring-hydraulic shock-absorbing strut leads to an increase in the resonant frequency by 1 Hz, however, the resonant peaks are reduced by almost 3 times to a dynamic coefficient of 2.5...2, which significantly increases the smoothness of the ride of non-suspension vehicles and reduces the likelihood of wheel separation from the supporting surface. CONCLUSIONS: The research has established that the proposed wheel with a mini-suspension in the form of a spring-hydraulic strut and a support roller has a relatively simple design, provides high vibration-protective properties with small amplitudes of kinematic disturbance and can be used to improve the smoothness and cross-country ability of wheeled non-suspension vehicles.

Numerical study of steady-state dynamic characteristic of non-pneumatic tire with local structural damage

Non-pneumatic tires (NPTs) fundamentally avoid the risk of tire blowout of traditional pneumatic tires, but the overall and key component performance inevitably degrades due to factors such as high temperature, variable load, variable working conditions and impact in its service process. Once this leads to failure, it will significantly impact on vehicle safety. To this end, this paper studied the influence of local structural damage on the dynamic response of NPTs, which lays the foundation for realizing health monitoring of intelligent non-pneumatic tires (INPTs). Firstly, a three-dimensional nonlinear finite element model of NPTs was established, and the failure locations of NPTs were determined by fracture mechanics and maximum strain energy density; Secondly, the influence of structural damage on the static and dynamic performance of NPTs was analyzed; Finally, the sensitivity of the acceleration signal and sensor position of the tire inner liner to the local structural damage was studied. The research results show that structural damage will cause the stress of the spokes and shear layer to increase, and as the number of broken spokes increases, the shear layer will bear a larger load. Compared with the circumferential and lateral acceleration, the radial acceleration has the highest sensitivity to the damage of NPTs. The sensor closest to the damage location is the most sensitive to the damage. The research results provide a reference for the structural optimization design and health monitoring of INPTs.

Regarding the issue of the influence of factors on the braking parameters of M1 category vehicles with electric or hybrid power unit

Problem. The relevance of this work is explained by the fact that there are no works at all in the reference and normative literature on the theory and practice of forensic auto technical examination, and even more so, methodical recommendations regarding the values ​​of the braking parameters of vehicles of the M1 category with an electric power plant. Goal. The purpose of the work is to establish the factors that affect the braking parameters of M1 category vehicles with an electric or hybrid power unit. Methodology. The approaches adopted in the work to solve the set goals are based on the theory of conducting the experiment, the theory of the interaction of the pneumatic tire with the road surface, the theory of the car and the laws of theoretical mechanics. Results. On the basis of the obtained experimental data regarding the value of permanent deceleration and the time value of the increasing deceleration during emergency braking of the M1 category vehicles with an electric or hybrid power unit, the tasks will be solved necessary for conducting forensic engineering and transport examinations for specific road traffic events with the participation of M1 category vehicles with an electric or hybrid power unit. Originality. The results of the study provided an opportunity to get an idea of the influence of factors on the braking parameters of M1 category vehicles with an electric or hybrid power unit. Practical value. The obtained results can be recommended to forensic experts when writing expert opinions or expert studies.

Influence of pneumatic tire enveloping behavior characteristics on the performance of a half car suspension system using multi-objective optimization algorithms

The interaction between a vehicle's tire and the road surface is pivotal for a driver's control over the vehicle's movements. It serves as the fundamental link between the vehicle and the road. The modeling of tires holds significant importance in contemporary vehicle design, playing a critical role in assessing aspects such as vehicle handling, ride comfort, and road load analysis. This study focuses on investigating the impact of the enveloping behavior characteristics of a pneumatic tire on the performance of a suspension system. The analysis of the vehicle's ride comfort utilizes a half-car model. Unlike a previous model with a single point of contact with the road, the presented suspension system, coupled with a four-degree-of-freedom rigid ring tire model, offers a more precise estimation of both ride comfort and road holding. The primary emphasis of this research lies in the modeling and evaluation of the proposed suspension system's performance. A comprehensive computer model of the entire system is developed using MATLAB software. This work enhances the existing framework by incorporating both a Multi-Objective Genetic Algorithm (MOGA) and a Multi-Objective Particle Swarm Optimization (MOPSO) to optimize the damping and stiffness coefficients of the passive suspension. This approach allows for a detailed comparison of the optimization capabilities and effectiveness of both algorithms in refining vehicle ride comfort. The results from MATLAB simulations highlight performance improvements, and the comparative analysis of MOGA and MOPSO provides insights into the selection of optimization techniques for suspension system design.

Innovative spoke design for non-pneumatic tyres with enhanced load-bearing capacity and customizability for all vehicles

For over a century, pneumatic tyres have been a crucial part of automobiles. Recently, non-pneumatic (airless) tyres have emerged, offering innovation but facing challenges in complexity, vehicle safety, adaptability, and load-bearing capacity. This research introduces a new spoke design for non-pneumatic tyres that outperforms conventional honeycomb and diamond spokes tyres in load-bearing capacity, while being less complex and customizable for various vehicles, including public transport. The study is structured into two phases. In Phase 1, the spoke design is selected from various CAD models using SolidWorks. This involves comparing the parabola design against prior design studies and honeycomb and diamond spokes concerning total deformation, maximum shear stress, equivalent (von Mises) stress, and maximum principal elastic strain with the help of FEA software Ansys. Results show that the Parabola design surpasses the pneumatic tyres in terms of load-bearing capacity, The parabola spoke design shows a consistent vertical stiffness under varying loads, ranging from 1500 N to 4500 N, with no sudden spikes or drops indicating structural instability. The objective is to identify the spoke design that best meets the performance objectives for phase 2 analysis. In Phase 2, the material selection and analysis are conducted. The goal is to determine the optimal polyurethane durometer rating for bus tyres. In this phase, the insights from Phase 1 are applied to scale up the design and choose suitable materials, showcasing the design’s adaptability from car tyres to bus tyres. Ansys will be used for analysing the total deformation of the tyre under a force of 40,000N, simulating the extreme operating conditions for bus tyres. This paper provides valuable data on non-pneumatic tyre spoke design, material selection, deformation analysis, design optimization, and standardization, enhancing vehicle safety and performance in public transport.

Optimizing the Honeycomb Spoke Structure of a Non-Pneumatic Wheel to Reduce Rolling Resistance

Traditional pneumatic tyres are prone to puncture or blowout and other safety hazards. Non-pneumatic tyres use a high-strength, high-toughness support structure to replace the “airbag body” structure of pneumatic tyres, which is made of fibre skeleton materials and rubber laminated layers, thus effectively avoiding the problems of blowout and air leakage. However, discontinuous spokes undergo repeated bending deformation when carrying loads, which leads to energy loss, of which the rolling resistance of non-pneumatic tyres is one of the main sources of energy loss. This paper focuses on the study of gradient honeycomb non-pneumatic tyres. Firstly, a finite element model was established, and the accuracy of the model was verified by numerical simulation and stiffness tests. Secondly, the order of the effect of different spoke thicknesses on rolling resistance was obtained through orthogonal test analysis of four-layer honeycomb spoke thicknesses. Then, four optimized design variables were selected in combination with the spoke angles, and the effects of the design variables on rolling resistance were analyzed in detail by means of the Latin hypercube experimental design. Finally, the response surface model was established, and the non-linear optimization model was solved by the EVOL optimization algorithm considering the tyre stiffness limitations so that the rolling resistance was minimized. The results of the study laid down theoretical and methodological guidance for the design concept and technological innovation of low rolling resistance comfort non-pneumatic tyres.

Rubber tracks and tyres: a detailed insight into force analysis during obstacle negotiation

The contact of a rubber track or a tyre tread with an edge corner is a process involved in many practical applications, i.e. traversing rough terrain and stair climbing. This paper presents a rigorous analysis along with experimental results to study what happens during the contact between a running gear and an edge corner as well as what forces are exchanged between these two elements by providing also a comparison between existing theoretical methods to assess which one is the most accurate. A testbed has been specifically developed for this research work to analyse the behaviour of a rubber specimen in contact with a step-like obstacle. The experimental results highlighted that the forces exchanged between a belt and a corner edge depend only on the relative inclination between the two sides of the belt and on the coefficient of friction while a pneumatic tyre patch behaves similarly to a belt when it is in contact with a step corner edge.

Development of spoke structure for agricultural non-pneumatic tire based on the decrease in soil compaction

Pneumatic tires are unsuitable for agricultural machinery due to their susceptibility to punctures from stumps in plantations. To address this, non-pneumatic tires (NPTs) were developed. This study experimented with and simulated the Michelin TWEEL NPT on sandy clay loam soil. An integrated method combining the finite element method and an empirical model was used to simulate NPT-soil compaction. A custom tire-soil compaction machine measured soil sinkage, aligning well with the experimental data. A novel arrow-shaped spoke for agricultural NPTs, made from polyurethane, significantly reduced soil compaction. Future work will involve prototyping and manufacturing this innovative agricultural NPT.

Steady-state rolling resistance prediction model of non-pneumatic tyres considering tread temperature: theory and experiment

Non-pneumatic tires have potential advantages over pneumatic tires, including lower rolling resistance. First, a non-pneumatic mechanical elastic wheel (ME-Wheel) was designed. Based on its structural characteristics, a tread temperature prediction model under steady-state rolling conditions was established, and the accuracy of the established model was verified through temperature measurement experiments. Combined with the tread temperature prediction model, a steady-state rolling resistance prediction model of ME-Wheel was established, and the basic parameters (ground length CL , ground width CW , radial stiffness SR ) required for the model were identified through experiments. Finally, the experimental data were compared with the predicted values under different speed and load conditions. The results showed that the average simulation value of the rolling resistance coefficient of ME-Wheel was 0.01853, which was positively correlated with speed and load. The test results and predicted values showed a similar trend under the same operating conditions, with a maximum error of less than 3.5%. This proved that the novel non-pneumatic tyre steady-state rolling resistance prediction model based on tread temperature could accurately predict the steady-state rolling resistance of tyres. This research addresses a significant topic in tyre technology and has the potential to influence future designs and optimizations of non-pneumatic tyres.

Numerical investigation and comparison of the aerodynamic characteristics of non-pneumatic tire and pneumatic tire

A non-pneumatic tire, in which the tire pressure is replaced by an elastic support body, is called an airless tire with elastic support (ALTES). In this study, the differences in the aerodynamic characteristics between ALTES and pneumatic tire (PT) were comparatively investigated using URANS simulations based on the DrivAer model. It was found that the vehicle body drag coefficient of the vehicle equipped with ALTES was reduced by 27% compared to that of the vehicle equipped with PT and had a significant drag-reduction effect. The drag coefficient and moment coefficient of the ALTES wheels are 2 and 3.5 times those of the PT wheels, respectively, which offset the drag-reduction benefits. The drag coefficient and aerodynamic power loss of vehicles equipped with ALTES were 97–102% and 108.5%–114% of those of vehicles equipped with PT. It is reasonable and necessary to evaluate the aerodynamic performance of ALTES based on the aerodynamic power loss. By suppressing the wheel ventilation flow and reducing the wheel drag, the aerodynamic wheel cover can reduce the aerodynamic power loss of a vehicle equipped with ALTES by 12%, and the vehicle aerodynamic performance is comparable to that of a PT.

Сервисное обслуживание пневматических шин на самоходные машины для подземных горных работ

The article presents the issue of short life of pneumatic tyres for mobile underground mining machines. It is noted that the correct choice of pneumatic tyres will increase the tyre life, but for a greater increase it is necessary to control the entire life cycle of the tyre, i.e. to carry out its service. The life cycle stages to be taken into account during tyre maintenance are presented. Control at each stage will minimise damage to the pneumatic tyres. The maintenance phase should include the records of tyre usage history and stock management. Analysis of the records will help to determine the reasons for tyre rejection and the wear conditions, the tyre condition before and after repair, and before and after retreading. Service maintenance of pneumatic tyres will allow planning the approximate level of stock, replacement periods and effective stock management. The article justifies the relevance of holding joint meetings of service specialists, tyre designers, and the company’s. In conclusion, it is noted that the issue of creating a national standard of service maintenance of pneumatic tyres for mobile underground mining machines is relevant.

Prediction of the Residual Resource of Pneumatic Tire Materials from Accumulation and Type of Damage

The present paper examines the mechanical characteristics at the boundary of the distribution of rubber matrix and metal and fabric fibrous materials as a distinct area in the crack braking mechanism, and their impact on the durability of pneumatic tires in the event of damage accumulation during operation. Experimental studies were conducted on the delamination of the components of the tire material composition in samples obtained from diverse locations of the car tire. The strength of the rubber matrix fibers of the metal cord was determined, which makes it possible to assess the overall strength of the tire material as a composition of reinforcing elements and the matrix during the accumulation of damage created artificially during operation. The method of experimental research is reasonably stable. The nature and behavior of the sample rupture during the tests were evaluated.

A toe-inspired rigid-flexible coupling wheel design method for improving the terrain adaptability of a sewer robot.

The human toe, characterized by its rigid-flexible structure comprising hard bones and flexible joints, facilitates adaptive and stable movement across varied terrains. In this paper, we utilized a motion capture system to study the adaptive adjustments of toe joints when encountering obstacles. Inspired by the mechanics of toe joints, we proposed a novel design method for a rigid-flexible coupled wheel. The wheel comprises multiple elements: a rigid skeleton, supporting toes, connecting shafts, torsion springs, soft tendons, and damping pads. The torsion springs connect the rigid frame to the supporting toes, enabling them to adapt to uneven terrains and pipes with different diameters. The design was validated through kinematic and dynamic modeling, rigid-flexible coupled dynamics simulation, and stress analysis. Different stiffness coefficients of torsion springs were compared for optimal wheel design. Then, the wheel was applied to a sewer robot, and its performance was evaluated and compared with a pneumatic rubber tire in various experiments, including movement on flat surfaces, overcoming small obstacles, adaptability tests in different terrains, and active driving force tests in dry and wet pipelines. The results prove that the designed wheel showed better stability and anti-slip properties than conventional tires, making it suitable for diverse applications such as pipeline robots, desert vehicles, and lunar rovers.

Investigation of Additive-Manufactured Carbon Fiber-Reinforced Polyethylene Terephthalate Honeycomb for Application as Non-Pneumatic Tire Support Structure.

A non-pneumatic tire (NPT) overcomes the shortcomings of a traditional pneumatic tire such as wear, punctures and blowouts. In this respect, it shows great potential in improving driving safety, and has received great attention in recent years. In this paper, a carbon fiber-reinforced polyethylene terephthalate (PET/CF) honeycomb is proposed as a support structure for NPTs, which can be easily prepared using 3D printing technology. The experimental results showed that the PET/CF has high strength and modulus and provides excellent mechanical properties. Then, a finite element (FE) model was established to predict the compression performance of auxetic honeycombs. Good agreement was achieved between the experimental data and FE analysis. The influence of the cell parameters on the compressive performance of the support structure were further analyzed. Both the wall thickness and the vertically inclined angle could modulate the mechanical performance of the NPT. Finally, the application of vertical force is used to analyze the static load of the structure. The PET/CF honeycomb as the support structure of the NPT showed outstanding bearing capacity and stiffness in contrast with elastomer counterparts. Consequently, this study broadens the material selection for NPTs and proposes a strategy for manufacturing a prototype, which provides a reference for the design and development of non-pneumatic tires.

АНАЛИЗ ВЛИЯНИЯ ОСНОВНЫХ ВНЕШНИХ СИЛ И РЕАКЦИЙ НА ВЕЛИЧИНУ БОКОВОГО УВОДА УПРАВЛЯЕМЫХ И НЕУПРАВЛЯЕМЫХ КОЛЕС ПРИ КРИВОЛИНЕЙНОМ ДВИЖЕНИИ ДВУХОСНОГО АВТОМОБИЛЯ

Pneumatic tires must have elasticity, strength, wear resistance and, taking vertical, tangential and lateral loads, must ensure vehicle stability when cornering. Optimization of their parameters and properties, often of a contradictory nature, is an urgent task, for the solution of which hypotheses were put forward based on the information and analytical research carried out and which made it possible to specify the purpose and objectives of subsequent research.

Development and Analysis of Additively Manufactured Non-Pneumatic Tires for Mars Rover

Mars rovers are developed using the most sophisticated technology. Competitions such as the University Rover Challenge (URC), European Rover Challenge (ERC), and Anatolian Rover Challenge (ARC) encourage students to become acquainted and experienced with cutting-edge technology. This paper focuses on the development and analysis of a modified version of a non-pneumatic tire (NPT) for the MIST Mars rover “Phoenix 2.0.” Recent studies show that NPT has a good potential to replace conventional tires. To optimize the tire design for the rover, many design aspects are considered. The additive manufacturing process is used to fabricate the tire model to ensure the proper geometrical shape and usage of material. Later, a static structural analysis is conducted to investigate the stress and deformation of the tire that it may experience during rover operation. The developed deformation and stress in this analysis are well protected by the honeycomb structures that are optimized from many design attempts. The result shows a positive indication of meeting the desired criteria that eventually results in the fabrication of the tire and participation in the ARC competition. This research will inspire others to contribute to the advancement of NPT in various circumstances where pneumatic tires perform inadequately.

Разработка стандартизированного подхода по выбору пневматических шин на самоходные машины для подземных горных работ

Orientation towards foreign suppliers with their methods and recommendations for tire application on mining machines without taking into account the requirements and specific features of operating conditions in the Russian Federation has led to a lack of domestic regulatory approaches to their use. The article justifies the relevance of developing a standardized approach to selection of giant tires. The development was initiated by “ERT-GROUPP” LLC. Standardization tools are presented, through which the basis for ensuring the quality and efficiency of mine machinery operation will be determined. Provisions of the standardized approach to selection of giant tires for mining machines are developed. An example of tire selection for the Epiroc ST1030 LHD operated in conditions of the Sheregeshskaya mine, EVRAZ ZSMK JSC, is given according to the developed approach to tire selection. The main directions in the industry for application of the standard for the selection of pneumatic tires for underground self-propelled mining machines are given. In conclusion, it is noted that the development of a draft standard for selection of giant tires for mining machines corresponds to the key directions in development of standardization and technical policy to provide the mining industry with modern standardization tools. The use of the national standard entitled “Mining equipment. Self-propelled machines for underground mine workings. The order of selection of pneumatic tires” will contribute to reducing downtime of mining machines associated with the incorrect selection of giant tires depending on the type of machine and the operating conditions, which will reduce economic and material losses of underground mining enterprises.

Numerical Simulation of Vehicle Tyre under Various Load Conditions and Its Effect on Road Traffic Safety

The main objective of the transport reliability and maintenance analysis is to improve the understanding of accidents through incident investigations. This research focuses on composite pneumatic tyres used in transportation engineering and presents both theoretical and experimental studies. The finite element method used for numerical simulation combined with pre-experimental measurements based on optimisation by material vibration response is presented for tyre material modelling. Piezoelectric vibration test was used for the pre-experimental test of the tyre quarters. The simulation results indicate that the pneumatic tyre with the recommended air pressure inflation shows the least amount of deformation. In comparison, pneumatic tyres with recommended and reduced air pressure inflation of 0.25, 0.5 and 0.75 bar are under research. Additionally, it was established that, when subjected to external forces that exceed the tyre’s maximum weight capacity, as determined by the manufacturer, the tyre exhibits significant stiffening and internal stress. The research suggests that this methodology can be used to obtain a realistic model of vehicle tyre dynamic processes and assess the impact on road traffic safety with different inflation pressures and loads.

Experimental and numerical investigation on radial impact of pneumatic tyre

Experimental testing and numerical modelling were conducted to investigate the dynamic responses of the pneumatic radial tyre subjected to radial impact loadings. A finite-element simulation strategy for the radial impact process of the pneumatic tyre was developed. Especially, uniaxial tensile tests at various strain rates up to the order of 102s−1 were carried out to obtain the required stress – strain data for the tyre rubbers. A three-dimensional constitutive model was proposed to characterize the nonlinear hyperelastic and viscoelastic behavior for the tyre rubber, and was incorporated via a user defined material subroutine in the radial impact simulation. Deformation profile of the radial tyre and velocity variation of the striker obtained from numerical simulations agree well with experimental results, which demonstrates the rationality of the simulation method and the validity of the proposed constitutive model. The stress data of the carcass ply inside the tyre, which is not easy to be known using the traditional non-destructive measurement technique, can be obtained by means of the proposed simulation method. Numerical results indicate that the carcass ply cords near the tyre shoulder have higher force levels during the radial impact process, and such tensile forces increase with the camber angle of the striker. The shear strain concentrations of the tyre rubbers in the carcass plies occur at the sidewalls near the shoulder and the bead.

Characteristic study and design factor analysis of a novel non-pneumatic tyre with V-shaped spokes

Compared with conventional pneumatic tyres, non-pneumatic tyres (NPTs) have various advantages such as zero-blowout risk, maintenance-free, and environment-friendliness. Instead of compressed air, NPTs employ elastic spokes as the main load-carrying structure. Honeycomb and flexible radial spokes are the commonly used types, and various spoke geometries are also continuously emerging. In this study, an innovative NPT with V-shape spokes was developed. With the specially designed V-shape spokes, the NPT can achieve better supporting performance and aerodynamic characteristics. A finite element (FE) model was constructed for the proposed NPT, and mechanical properties were studied. Prototypes of the proposed NPT were fabricated, and experimental test confirmed the fidelity of the FE model. To reveal the impact mechanism of design parameters on the mechanical properties of the proposed NPT, we used the Taguchi method for parametric analysis. Based on the verified FE model, orthogonal experimental simulations were conducted to study the interactions among the design parameters and the multi-axis properties such as the radial, longitudinal, lateral, and torsional stiffnesses. Based on the result analysis, design principles are extracted for the proposed NPT to satisfy its multi-axis mechanical property demands.