Tire Performance Characteristics Research Articles

Datum ranking and analysis of factors affecting tire wear

Relevance of the work. The operational efficiency and technical condition of mining vehicles to a large extent depend on the service life and performance characteristics of tires. The most important technological process that determines the effectiveness of field development is the transportation of rock mass. The share of motor transport costs in the total cost and production by open method at Russian mining enterprises is significant, and reaches 70% as the depth of open pits (cuts) increases. At the same time, the actual productivity of mining trucks is much lower than their technical and technological capabilities, and this difference is up to 2.5 times or more for various brands of vehicles, including imported ones. Today, both consumers and manufacturers of large tires are interested in the most efficient tire production management. Purpose of the work: consideration of the main factors affecting tyre life, as well as datum ranking of these factors to determine the degree of significance of each factor. Methodology of research. The systematic approach was used including datum ranking method, some analytical, computational methods and generalization. Results. The ranking was carried out by three independent groups of experts on a number of proposed factors. The main factors in each group were identified and the degree of agreement between the opinions of the interviewed specialists was evaluated. The general opinion of various expert groups on the significance and ranking of factors affecting the integrity of giant tires is confirmed. Conclusions. Datum ranking and analysis of factors affecting the wear of giant tires of mining dump trucks significantly affect the optimization of machine operation and, with appropriate adjustments, can give a positive economic effect.

Specifics of certification of agricultural tires with maximum consideration of their operating conditions

The problems of product quality and competitiveness are typical in the modern world. The international market constantly demands the improvement of the performance properties of automobiles, tractors, agricultural machinery and other types of mobile vehicles. At the same time, they can not be increased without significant improving of the tire performance characteristics. Pneumatic tires are among the critical units of mobile vehicles that have a significant impact on the following performance properties; therefore, as a complex product, they were included in the list of approval in accordance with Regulation No 106 for agricultural vehicles and their trailers. The purpose of the research was to develop recommendations for improving the methodology of conducting certification tests of agricultural tires aimed at improving product quality. The article discusses the methods of certification and approval of tires for agricultural vehicles and their trailers. The drawbacks of the method of certification of agricultural tires using the method of automobile ones are analyzed. It is proposed to supplement the certification with test methods developed in the Russian Federation that are as close as possible to the operating conditions of agricultural vehicles and tires of traction machines. The experience of work of “Bridgestone” and “Michelin” companies in the Russian Federation is presented. The absence of a national tire certification system in Russia influence in many cases vehicle breakdowns, which lead to downtime, as well as to the occurrence of accidents. In case of serious accidents in transport, when there is insufficient clarity of the causes of the accident or it is clear that the accident is related to tire failure, the victims initiate legal proceedings against the manufacturers, involving the payment of monetary compensation. At the same time, mass production defects are usually hidden behind the losses of consumers. To improve the quality of agricultural tires, it is proposed to revise UN/ECE Regulation No 106 as close as possible to operating conditions, as well as to create an independent accredited tire center.

An Analysis of Recreational Off Road Vehicle Tire Performance Characteristics

An Analysis of Recreational Off Road Vehicle Tire Performance Characteristics

A procedure for multi-objective optimization of tire design parameters

Article history: Received September 9 2014 Received in Revised Format October 23 2014 Accepted November 25 2014 Available online November 26 2014 The identification of optimal tire design parameters for satisfying different requirements, i.e. tire performance characteristics, plays an essential role in tire design. In order to improve tire performance characteristics, formulation and solving of multi-objective optimization problem must be performed. This paper presents a multi-objective optimization procedure for determination of optimal tire design parameters for simultaneous minimization of strain energy density at two distinctive zones inside the tire. It consists of four main stages: pre-analysis, design of experiment, mathematical modeling and multi-objective optimization. Advantage of the proposed procedure is reflected in the fact that multi-objective optimization is based on the Pareto concept, which enables design engineers to obtain a complete set of optimization solutions and choose a suitable tire design. Furthermore, modeling of the relationships between tire design parameters and objective functions based on multiple regression analysis minimizes computational and modeling effort. The adequacy of the proposed tire design multi-objective optimization procedure has been validated by performing experimental trials based on finite element method. © 2015 Growing Science Ltd. All rights reserved

Reliability Approach to Horizontal Curve Design

AASHTO's Policy on Geometric Design of Highways and Streets contains geometric design criteria for horizontal curves for new and major reconstruction. These criteria are based on design side friction factors that were established in the 1940s. The objective of this research was to establish a probabilistic approach to the design of horizontal curves and compare the results with current design criteria. Reliability analysis commonly is used in structural engineering and recently has been used in stopping sight distance research for transportation design. In this research, design variables were considered random instead of deterministic to incorporate variations that occurred in the field (e.g., driver heterogeneity or differences in tire performance characteristics) into the analysis. The effects of wet pavements and tire characteristics for passenger cars and heavy trucks were considered. The superelevation rate was considered as a design input, and minimum radii for a target reliability index were presented for combinations of input mean speeds and superelevation rates. All other design inputs were considered random variables (e.g., available pavement friction), along with their appropriate distributions, in the reliability analysis. The results show that a target reliability index of 3.0 is appropriate for use in the probabilistic design of horizontal curves. Furthermore, when only skidding failure is considered, the design criteria for passenger cars can reasonably accommodate heavy trucks. The recommendations for future research consider probabilistic methods and more complex models of horizontal curve forces.

Prediction of Tire Shape Change During Post Cure Inflation

Abstract One step in the tire manufacturing process may be post cure inflation. In this step, the tire is cooled from cure temperature to below the glass transition temperature of the fabric cords while being held at a constant inflation pressure. Due to the thermal effects and creep of the component materials, the shape of the tire will be different after the post cure inflation than before. This change in tire shape from that in the mold drawings should be accounted for in performing finite element analyses to predict tire performance characteristics. This paper describes a modeling methodology that predicts the tire's shape change through the post cure inflation process using the finite element method. This is a complex process to represent analytically, with many different mechanisms contributing to the deformations of the tire. These include thermal expansion/shrinkage of the rubber and cords as they cool, creep of both the rubber and fabric cords, and change in material moduli. Since these mechanical effects are temperature dependent, the model uses results from the thermal history prediction model presented previously. The quality of the modeling process was assessed by comparing predicted to measured dimensions for several tire constructions and sizes. Selected results are presented to show the accuracy of the modeling procedure.

Designing elastomer network for desired tire performance characteristics

AbstractRubber elasticity is associated with changes in configurational entropy of a long chain. Because the chain cannot change its configuration instantaneously, there is a time delay in deformation to an applied force. This delayed response is the source of viscoelasticity and hysteresis energy loss of elastomer networks. Many tire performance properties are related to the viscoelasticity of tire components. Wet and dry traction of tire is related to the energy loss of the tread material at very high frequencies. On the other hand, rolling resistance of tire is characterized by the energy loss of tread material at relatively low frequencies. The dynamic viscoelastic properties of elastomer network shows characteristic zones on a frequency scale. At very high frequencies the energy loss is controlled by the segmental motions of the polymer chain. At lower frequencies the energy loss is related to the longer range motions of the chain. A series of polymers was synthesized to study the effect of micro‐ and macro‐structure of the polymer on the viscoelastic properties of tread compounds and their tire performance properties. As expected from the theory, the wet traction of the tire was highly correlated to the segmental motions of the chains; namely, the glass transition temperature of the polymer. The energy loss of the compounds at a higher temperature, however, was related to the macrostructure of the polymer chain. Those examples illustrate that the fundamental understanding of the theory of elastomer network allows a tire engineer to obtain the best balance of tire performance characteristics.

Effect of Material Properties on Tire Performance Characteristics — Part II, Tread Material

Abstract This report, on the effect of tread materials on tire performance, continues the study in Part I [1] on the analogous effects of cords. A new “deformation index” concept for the characterizing energy loss is proposed. Principles are developed for maximum correlation of this index to rolling resistance, wet and dry traction, ice traction, and cornering force. The deformation index is used to determine the dynamic property most relevant to each of these tire functions.