Static and Dynamic Analysis of Non-Pneumatic Tires Based on Experimental and Numerical Methods

Since the beginning of their production, pneumatic tires have experienced tremendous improvements in structure and materials, becoming the dominant design in the world tires market. Nevertheless, relying upon pressurized air, they are affected by maintenance and security issues that can lead to fatal accidents. Therefore, tire-makers are investigating new tire designs, called Airless or Non-Pneumatic, with the aim of removing air-related problems. The research about such tires is still at an early stage, especially if compared to the one conducted on the pneumatic ones. In this paper, the development of a methodology capable of studying the mechanical behavior of a Non-Pneumatic Tire (NPT) by means of experimental data and numerical approach is illustrated. The experimental activities consisted of a scanner acquisition of the NPT and a footprint analysis for the calculation of the radial stiffness and contact patch pressure distribution. Moreover, the Digital Image Correlation (DIC) technique was applied to carry out a more specific study about the spoke’s deformation. From the acquired 3D model, a calculation of the NPT vertical deflection with finite element analysis (FEA) was performed—validating the model and then submitting it to a steady state analysis—that allows the simulation of a steady state rolling tire with the possibility to replicate different values of slip ratio. The results of the experimental activities are in good agreement with the ones obtained with FEA, further validating the developed methodology.

Analisis Beban Statis dan Explicit Dynamic Roda Tanpa Udara yang Menggunakan Hexagonal Honeycomb Spokes Pada Kendaraan Taktis TNI

Non-Pneumatic Tires (NPT) have been used in several sectors since the wide application and following with advantages of the simplicity in maintenance. In this paper, the static and explicit dynamic behavior of NPTs is investigated with several different honeycomb spokes. The component of NPT with a hexagonal honeycomb type consists of a hub wheel, outer ring, spokes, and tread. The six models of NPT are denoted with the variation of spokes thickness (20 and 30 mm) and thickness of the wheel tread (3, 5 and 7 mm). Based on the computer simulation results, the B3 type NPT has an excellent ability to accept loads with deformation, which is 14,358 mm and the stress is 270 MPa.

The strength of the communication elements of pneumatic tires as composite material

The mechanical properties at the boundary of the distribution of the rubber matrix and metal and fabric fibrous materials as a separate area in the mechanism of crack inhibition and its effect on the durability of pneumatic tires during the accumulation of damage during operation are considered. Experimental studies on the stratification of the elements of the composition of the tire material in samples made from different parts of the car tire. The strength at the contact boundary "rubber matrix-fibers of metal cord" and between the fibers of the cord, which allows to assess the total strength of the tire material as a composition of reinforcing elements and the matrix in the accumulation of damage created during operation, artificial the nature and behavior of the rupture of the samples during the tests, the morphology of fracture on the surface of the interaction of the reinforcing fibers of the wire with the rubber matrix was evaluated.

A STATE OF ART AND PROSPECTS OF USED PNEUMATIC TIRES MANAGEMENT (REVIEW)

The basic data on the volume of production of pneumatic tires in the world and in Ukraine are presented. The need to improve the ways of handling pneumatic tires that have lost their con-sumer properties (worn out tires as a result of their intended use and tires rejected as a result of passing quality control during their manufacture) is shown as one of the most dangerous for the environment and promising in terms of using their properties. A detailed classification of methods for handling worn out and defective tires is proposed and a critical analysis of each of them is given. Particular attention is paid to the methods of utilization of tires, in particular, recycling, which makes it possible to efficiently use the secondary raw materials obtained from tires directly for their intended purpose. The features of physical, physicochemical and chemical processing methods, in particular combustion, gasification, pyrolysis of tires and their frag-ments, as well as the prospects for their decomposition under the influence of environmental factors, in particular microorganisms, are also considered. The main ways of solving the prob-lem of tires that have lost their consumer properties in Ukraine are proposed. Bibl. 88, Fig. 2.

SIDE SLIP OF WHEELS WITH LOW AND ULTRA-LOW PROFILE TIRES OF A PERSONAL CAR NEGOTIATING A TURN

This article studies the influence of the speed of a car with low and ultra-low profile tires, 14ʹʹ and 16ʹʹ, negotiating a turn through an interactive software system developed by us in the MATLAB environment. The changes of the normal and lateral loads of the wheels are obtained and the characteristics of the side slip angle (known as side slip) of the pneumatic tires are determined. Taking into account the side slip of the wheels, the software determines the center of the turn. The characteristics for the normal and lateral loads and of the side slip of the wheels for both types of tires are given. The influence of the tire profile on the handling characteristics is analysed. Recommendations are proposed for a personal car’s motion in a turn with both types of tires.

Substantiation of prospective direction for developing devices to reglate pressure in truck tires

Analysis of the theory of the car and its basic elements makes it possible to state the exceptional importance of the pneumatic tire, which provides movement during the operation of the vehicle. The most important parameter that characterizes the condition of the pneumatic tire is the pressure, which can fluctuate during movement, but, at the same time, is a controlled parameter due to the possibility of inflating the tire in the presence of special devices during movement. Methodology. The purpose of the article is a reasonable prospect of creating new models of devices for tire pressure regulation in trucks. To achieve this goal, the methods of hypothesis, mathematical modeling to confirm it, methods of analysis, generalization were used. Results. The article proves that under the influence of the load on the wheel, the air temperature in the tires will be different and, accordingly, there will be differences in the pressure parameters in the pneumatic tires of trucks. In this regard, the solution to the issue of tire pressure regulation in trucks should be considered from the standpoint of differentiated pressure regulation, taking into account the difference in pressure parameters, which allows pumping each individual tire without a forced stop. Originality. The scientific novelty of the article is that it substantiates the promising direction of development of pressure monitoring devices in truck tires based on the analysis of the theoretical model of heating the pneumatic tires. Practical value. The practical significance of the study is that the article identifies the need to change approaches to pressure regulation based on the transition from centralized pumping systems to pumping systems based on a differentiated approach to individual air pressure control systems in truck tires.

Time factor research of tires tread wear for selfpropelled scraper

Problem. The publications analysis about the self-propelled scrapers use on sites of road and reclamation construction is showed that during the performance of working operations there is unacceptable wear of the tires tread as a result of the intensive sliding on the support surface. Over time, the pneumatic tires wear leads to decrease on the durability of the wheeled mover or tire failure as a result of the carcass rupture and the tread delamination. In its turn, the time factor of the tire tread wear depends directly on the duration of the scraper operating cycle, which implements the traction and transport modes. Goal. The life time increasing of the wheeled mover for the self-propelled scraper by reducing the tire tread wear. Methodology. Analytical methods for interaction process research of the pneumatic tires with support surface are used. Mathematical modeling methods were used to determine the time factor of the tire tread wear during scraping. Results. Dependencies for determining the duration of operating cycle components according to the elliptical scheme of scraping organization are presented. Based on the proposed mathematical model, such as takes into account the force, speed and time factors, the fractions of tire tread wear are determined by the components of the scraper operating cycle, which including its maneuvering in the face. It was found that most often the tire tread wear occurs when moving of the soil-loaded scraper. The presented calculation results of the tire life time according to the proposed method are showed the sufficient convergencewith the scraper performance attributes, taking into account only the abrasive mechanism of the tire tread wear. Originality. To determine the life time of pneumatic tires for the self-propelled scraper, as the most fully combined characteristic features of the traction and transport machine, it is proposed to use the preferred mechanism of tire tread wear – abrasive, as well as the deformation models of the pneumatic tire and support surface. Practical value. The use of the proposed method for calculating the tire tread wear will to make the life time forecast of the wheeled mover for the self-propelled scraper at the design stage and to determine the reasonable needs for material and technical means of this machine operation.

Determination of tangential properties of a single pneumatic tire in the vehicle braking mode of a vehicle

Problem. In the event of circumstances that may cause a traffic accident (accident), drivers apply emergency braking, which usually leads to the blocking of car wheels and the formation on the road surface of track information from pneumatic tires. If automated brake force control systems are installed in the brake actuator of the vehicle, the tracking information from the pneumatic tires may be absent or weak, and the braking efficiency of the wheeled vehicle will depend on the angular deformation of the tire relative to the road surface, which in turn is limited. coupling properties in the contact spot "tire-road surface". Goal. The aim of the work is to improve the method of determining the angle of twist of the pneumatic tire of a single car wheel in the mode of its braking by taking into account the effects of the coefficient of friction-sliding on roads with high traction. Methodology the peculiarities of twisting the pneumatic tire of a car wheel with a single busbar in the mode of vehicle braking on roads with low and high coefficient of friction - sliding are considered. The analysis of the model of dynamic change of the tire twist angle depending on the sliding of the tire tread elements in the spot of contact with the road surface is performed, and the results of simulation modeling are obtained, which are confirmed by experimental experiments. Originality. An empirical dependence is proposed, which takes into account the nature of the decrease in the value of the angle of twist of the tire on roads with high traction properties. Practical value. The obtained results of simulation modeling according to the proposed dependence determine that the highest indicators of torsional rigidity of the pneumatic tire are reached at a tire pressure of 0.8 MPa and a vertical load on it of about 2.6 104 N.