Airless Tire Research Articles

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.

TPMS-based auxetic structure for high-performance airless tires with variable stiffness depending on deformation.

A novel auxetic structure applicable to airless tire spokes is designed based on the primitive-type triply periodic minimal surface (P-TPMS) to have higher stiffness through deformation under compressive force. For becoming higher stiffness by deformation, an unit cell of auxetic structure is proposed and its characteristics according to design parameters are studied. Based on the parametric study, a rotated primitive-type auxetic structure (RPAS) is designed, and the deformative behaviors of an airless tire with the RPAS spokes are compared with a generally used honeycomb spoke. Simulation and experiment results show that the designed RPAS tire exhibits more stable behavior through higher rigidity depending on the deformation state when compressed on flat ground and obstacles. This variable stiffness characteristic of RPAS tires can be advantageous for shock absorption and prevention of large local deformations. Also, the manufacturability of the designed auxetic structure is evaluated using real rubber-based additive manufacturing processes for practical application in the tire manufacturing industry.

Enhancing airless tire performance for military vehicles: natural rubber compound with carbon black Fillers N220 and N550 with dynamic mechanical analysis approach

Enhancing airless tire performance for military vehicles: natural rubber compound with carbon black Fillers N220 and N550 with dynamic mechanical analysis approach

Advancements in Bicycle Safety: Integrating Control Sensors and Artificial Intelligence for Enhanced Airbag Innovation

Abstract: Motorcycle safety is a critical concern in traffic systems worldwide. This paper introduces a novel approach to enhancing rider safety through the integration of airless tires and advanced airbag systems, underpinned by artificial intelligence (AI) and control sensors. Airless tires contribute to vehicle stability by eliminating the risk of sudden deflation, while AI-driven airbag systems promise dynamic protection for riders during collisions. The study begins with an analysis of airless tire technology, emphasizing its impact on motorcycle stability and safety. It then transitions to the development of motorcyclespecific airbag systems, which utilize AI to process sensor data and make real-time decisions regarding airbag deployment. The effectiveness of these systems is validated through crash simulation tests and impact force measurements, demonstrating a substantial reduction in injury severity. Challenges such as cost, user acceptance, and technical constraints are thoroughly examined. The paper concludes with a discussion on future trends, including the potential for AI to predict and prevent accidents before they occur, thereby setting a new standard for motorcycle safety.

Directional damping design of viscoelastic composites via topology optimization

Design of architected functional materials that possess desired damping performance is a topic of great interest in both academic research and industrial applications. This study investigates the concept of ‘directional damping’ for viscoelastic composites and develops a topology optimization framework to achieve directional damping design. Microstructures with both load-bearing capacity and dominant damping in the prescribed direction are obtained by maximizing the loss factor while imposing stiffness constraints. An optimized directional damping microstructure design exhibits a loss factor 1.8 times higher than the isotropic design in the prescribed direction. It is found that the optimized configurations with curved viscoelastic strips are similar to wavy ‘suture’ lines in the beaks of woodpeckers, which possess outstanding energy absorption performance. We have also verified the superiority of the directional damping design through numerical simulations and experiments of the microstructured composites. The experiment results show significant reduction of peak response for the directional damping design compared to the isotropic counterpart. To demonstrate the application potential of the optimized unit cell microstructures, a novel conceptual airless tire that exhibits improved stiffness and shock absorption performance is designed and validated through both numerical simulations and experiments.

Optimization of Natural Rubber Formulation for Military Vehicle Tread Using Filler Carbon Black Type N220/N550

This study aims to optimize the formulation of natural rubber (Hevea brasiliensis) into a compound for applications in military vehicles when passing through various field conditions. Natural rubber types SIR 20 and RSS 1 were used with Carbon Black types N220 and N550 as fillers. In this study, samples that were both normal and samples that had aged for 72 hours at 70°C were created. The results showed that the mixture of RSS 1 - CB N220 (i.e., 100 phr–75 phr) influenced strength and stiffness. The physical and mechanical properties of the specimens, including curing time, tensile strength, tear strength, elongation at break, and compression set had been defined. By utilizing the resulting mechanical characteristics, rubber compounds are optimized to meet the specific requirements of airless tires, including durability, comfort, and performance. It is anticipated to create an airless tire that provides essential performance while reducing the risk of punctures and flats.

INVESTIGATION OF OVER OBSTACLE PERFORMANCE ANALYSIS OF AUXETIC AIRLESS TYRES

Advancing technologies are leading to the development of airless tire designs that can perform well on challenging road conditions. These designs include lattice structures, mesh structures, and periodic structures, among others. In this study, three different tire designs were analyzed using finite element analysis (FEA) to evaluate their strength and dynamic behavior. Dynamic analyses were conducted on two commercial designs and one original design with re-entrant lattice structures. The study found that these structures are versatile as they provide multiple load paths to resist deformation and failure, and they can be modified to produce different properties like stiffness and strength. The original design with re-entrant structures demonstrated mechanical properties that were twice as good as other commercial tires. Moreover, a spline-lined structure was developed, and it was discovered that a two-stage tire design could enhance strength. The analyses were conducted at specific and controlled speeds with a designated bump size. The new design demonstrated at least 66% higher impact absorption energy performance than other car tyres examined. In total, nine analyses were performed, making a significant contribution to the development of airless tire design.

High Stability in Compressive and Shear Behavior of Airless Tire Using Primitive TPMS-Based Cylindrical Spoke

High Stability in Compressive and Shear Behavior of Airless Tire Using Primitive TPMS-Based Cylindrical Spoke

Airless tires in the LEON-T project: How can they reduce tire/road noise emission

For more than a century, pneumatic tires (inflated with air) have totally dominated the market for road vehicle tires. However, in the recent two decades, interest has grown in developing airless tires; tires whose load is not carried by the inflation by air, but by the mechanical structure that connects the belt and rubber tread with the hub. The EU project LEON-T includes a part in which prototypes for innovative heavy goods vehicle (HGV) tires are developed, with the main purpose to reduce noise emission by 6 dB. To reduce noise that much it is believed that airless tires are needed. In LEON-T, two airless tire prototypes are intended to be developed by partner Euroturbine, in cooperation with other partners and subcontractors. Originally, the load-carrying material was intended to by composite material (reinforced plastic), but initial calculations have shown that a stronger material is needed; consequently, steel springs are currently being used. This paper will describe the principle of airless tires but with focus on the version being developed in LEON-T. The main part of the paper will deal with the noise generation mechanisms and the ways that airless tires can reduce the noise emission are thoroughly identified and discussed.

Design, properties, and applications of non-pneumatic tires: A review

The interest in airless or non-pneumatic tire (NPT) structures emerges due to potential performance and environmental advantages, such as reduced rolling resistance and improved recyclability, when compared with traditional rubber-based pneumatic tires. NPTs can already be found in commercial applications such as forklifts, electric scooters, and wheelchairs. Even so, up to the knowledge of authors, there is no known established large-scale production of NPTs for most applications. This work presents a systematic literature review regarding the mechanical design and development of NPTs. A summary of structural characteristics and mechanical behaviour analysis is provided. Relevant standards, analysis strategies, materials, production techniques, and the end-of-life of tires are addressed. In the end, the authors debate the current challenges and prospects of these emergent products. Furthermore, this research aims at being used as a tool, potentiating the development of innovative and efficient, airless tire solutions. The review presented clarifies that many academic efforts are focused on finding optimal functional designs, which are frequently complex and physically demanding. These geometrically complex design proposals are, in most cases, composed of intricate cellular structures and spokes arrangements. Based on the current lack of knowledge, authors identify key research areas to be further developed such as the production, performance, and reliability of NPTs. It is debatable whether there will ever be a shortcoming of the rubber tire, or a time when fully recyclable tires are a societal obligation. Nevertheless, the number of reasons to promote the development of a reliable replacement to the traditional tire is far from scarce.

Research on a tubeless tire for a mobile robot

Airless tires are used not only in cars, but also in vehicles used in the construction, road, forestry, and robotics industries. In order to develop the construction of an airless tire, its optimization at the stage of their design, a comprehensive method of researching the operational properties of an airless tire is proposed. The methodology includes stress-strain analysis, modal and thermal analysis of an airless tire using three-dimensional modeling using the finite element method. The airless tire was studied in the following modes of uniform movement of the wheel on a solid base: driven wheel; driving wheel; free wheel; neutral wheel; brake wheel. An example of the study of an airless tire of a mobile robot is given.

Study on clarification of the mechanism for tire force generated in airless tire during rolling motion

Study on clarification of the mechanism for tire force generated in airless tire during rolling motion

Study on clarification of the mechanism for tire force generated in airless tire during rolling motion

Study on clarification of the mechanism for tire force generated in airless tire during rolling motion

Study of Tweel Non-Pneumatic Tires

Abstract: Non-Pneumatic Tyre (NPT) is an airless tire that supports the weight of the car. Although tires manufactured of solid rubber exist, they don't provide a smooth ride even though they have enough compliance if used in conventional vehicles. The NPT discussed here is mainly divided into three parts. Deformable spokes that support the downward weight, a rigid hub, Tread made out of rubber which comes into contact with the road and Reinforced shear band also plays a vital role. The properties of Non-Pneumatic Tyres like contact pressure, rolling resistance, and weight carrying capacity can be varied by differentiating the dimensions or the manufacturing materials used to produce NPT. Many kinds of research are taking place all over the world to make NPT an alternative option to the traditional pneumatic tire over a decade. This paper integrates an overview of the research works that were carried out to develop and improve NPT. Keywords: Pneumatic, Tweel, Honeycomb structure, Hyperelastic

The COMPOND COMPOSITION OF AIRLESS TIRE TREAD (AIRLES TYRE)

The tire without air is a tire that has a very extraordinary influence on the units of vehicle users, both public vehicles and tactical vehicles in the military. In addition to being used in the field of duty, this airless tire can be used for other supporting vehicles of army so there are not many obstacles during operations. Therefore, it takes good materials and proper calculations in making this airless tire tread so that in the future there are no obstacles when using it. The research methods used are experimental methods and field studies. The study was conducted repeatedly and the data was taken directly in the field. After mechanical testing of the rubber material is done to find out the physical properties of the strength of the material. Furthermore, the entire printing and assembly process is carried out and tested on the vehicle, for the conclusion of static analysis of rubber sample material that has been done has determined the proper hardness for the material connected with polyurethane, the appropriate hardness for this rubber is 80 KN/mm. The process has been tested from each sample of rubber hardness variations and the results are determined, in addition to rheometer testing or maturation process takes 5 minutes and is given a temperature of 100 °C and is assisted by hydraulic so that air from volcanic rubber is lost with the help of hydraulic pressure.

Comparison of two different surface for rolling airless tire by finite element method

Drum testing was carried out to determine rolling tire performance. The finite element method was used to model the drum testing instead. In order to yield accurate results, the generalized Maxwell’s viscoelastic material model with hyperelastic material model was employed to simulate the drum testing on the airless tire. However, it consumed a lot of simulation time because of the contact surface between tire and drum was difficult to compute by using a finite element method. The finite element model of rolling an airless tire on a flat surface was developed. The contact patch and spoke deformation were carried out to investigate the surface effects. The spoke deformation of rolling an airless tire on a flat surface was found to be in accord with the curvature surface of the drum. The flat surface showed little difference in the contact area against the drum. Particularly, it was found that the analysis time of rolling an airless tire on a flat surface was less than the drum 10.13 times.

Study of Mechanical Properties of 3D Printed Material for Non-Pneumatic Tire Spoke

The spokes of airless tire or non-pneumatic tire (NPT) are normally made with thermoplastic polyurethane (TPU), which is highly elastic material, to replace inflation pressure in conventional pneumatic tire. However there are limitation in designing of complex spoke geometries due to difficulty in manufacturing process, which normally involve molding process. Recently, the 3D printing technique has been improved and can be used to create highly complex geometries with wide range of materials. However the mechanical properties of printed spoke structure using 3D printing technique are still required to design and development of NPT. This research aim to study the mechanical properties of TPU while varying in printing conditions. The specimens were prepared from actual NPT spoke using waterjet cutting technique and 3D printing technique according to the testing standard ASTM D412 and D638, respectively. The tensile tests were performed on the specimens with corresponding crosshead speed. The testing speed of 3D printed specimen were also varied to 100 and 200 mm/min to study the effects of strain rate on mechanical properties. The stress-strain relationships were obtained from tensile testing and the important mechanical properties were then evaluated. The mechanical properties of specimens prepared from actual NPT spokes and 3D printed specimens were then compared. The ultimate stress of specimens prepared from actual NPT spokes in radial direction and 3D printed specimens with 100% infill were found to be 32.92 and 25.47 MPa, respectively, while the breaking strain were found to be 12.98 and 10.87, respectively. Thus, the information obtained from this research can be used to ensure the possibility in creating NPT spoke using 3D printing technique based on elastic material such as TPU.

Optimized Stress-Strain Ranges for Hyperelastic Constitutive Models Supporting the Simulation of Vertical Stiffness on Airless Tire

The airless tires are developed to overcome a disadvantage of pneumatic tire which lost maneuverability caused of flattening and blasting. The finite element analysis (FEA) is an effective method for development of airless tires which have a complex construction. The material properties which describe mechanical behavior of each tire component are very important to yield accurate result. The high order constitutive model usually obtains the accuracy of FEA results. Unfortunately, it consumes the simulating time. The suitable stress-strain range of Mooney-Rivlin and Ogden model was selected in this research. The vertical stiffness of airless tire model was compared to the experiment. This study found that the accurate result and consuming less time of TWEEL airless tire model depended on an appropriate pair of material properties. There were 100% of tread and 30% of spoke stress-strain characteristic based on the Mooney-Rivlin model. Consequently, the study and design of airless tire by finite element method will be carried out efficiently in the further works.

Design optimization of Airless Tyre - Numerical Approach

The airless tire is a solitary unit supplanting the pneumatic tire, haggle get together. It replaces all the segments of a normal outspread tire and is included an inflexible center point, associated with a shear band by methods for adaptable, deformable polyurethane spokes and a track band, all working as a solitary unit. An airless tire is a singular unit overriding the pneumatic tire, in getting get together. The problem in the pneumatic tyre is life of the tyre is less, danger of explosion, maintenance cost is high, pressure monitoring is required. It replaces all of the fragments of an ordinary extended tire and is contained an unyielding focus point, related with a shear band by strategies for versatile, deformable polyurethane spokes and a track band, all filling in as a singular unit. In this paper, air less tire model is presented with a substitution of common elastic materials instead of engineered elastic in track and polyester instead of nylon in body. The development and material investigation of different kinds of air less tire is finished by contrasting and pneumatic tire. The design of the Airless tyres structures is done in solidworks. A concise underlying investigation has been done on spokes of airless tire and broke down by ANSYS programming. Investigation has been completed on different structures like Spokes, triangular and custom structure of circular and Hexagon with an applied load of 1000N. Correlation study has been completed among different structures with various materials and it study shows that tire with round structure with engineered materials gives less twisting contrasted with other structure.

Multiphysics Analysis of Contact Pressure Profile of Airless tires as compared to Conventional Tires

Abstract The harsh climate of the Arctic has always posed significant challenges to car drivers. The severe loss in traction due to snow and icing on the roads has led to an increased risk of collisions. The chapter compares the conventional air-filled tire with a nonpneumatic tire to improve the grip in the Arctic conditions. The grip obtained for tires is determined by the weight of the car and the friction between the tire and the road. The friction coefficient, used to determine friction, is a function of the contact pressure. This chapter discusses research work to obtain a concentrated pressure profile for the airless tire, compared to a conventional tire. A finite element analysis using ANSYS® Workbench is performed on two distinct models. The different pressure profiles of the models are analyzed, and the results proved the nonpneumatic tires have a more concentrated pressure profile with higher-pressure values.