Relationship between Deflection and Contact Area of Drive Tire

Conducting approval tests of vehicles, especially in the case of trucks outfitted with special bodywork in many cases is difficult or impossible to carry out and unprofitable. For this reason, it is proposed to assess of the stability and vehicle dynamics use the theory of similarity, on the basis of the vehicle on a 1:5 scale. The possibility of transferring the results of a full size vehicle requires compliance of selected dimensionless parameters, including tire parameters. The paper shows the various types of tires test, under static conditions and installed in the vehicle. The aim of the study was to determine the characteristics of directional and cornering stiffness and the answer how they affect on the behavior of the vehicle including: sideslip angle the center of gravity, inclination angle, yaw rate and gradients of acceleration.

Journal of Solid Mechanics and Materials Engineering, 2010

From a traffic safety point of view, there is an urgent need for intelligent tires which can optimize braking control by estimating the slip ratio and friction coefficient between road surface and tire. In previous studies, we have proposed an application of strain data for estimating a friction coefficient. However, it only investigated the condition when the vertical or frictional loads changed but the other load remained constant. Since both of the frictional and vertical loads alter the measured strain data, an independent applied load estimation method is needed. This study develops a concurrent method for estimating the frictional and vertical loads applied to the tires from the measured strain data when both loads change. The method decomposes the measured circumferential strain to the frictional and vertical strain components using their symmetrical and anti-symmetrical characteristics. FEM analysis is used for simulating tire deformation under various wheel loads and braking torques and the relationship between the strain distribution at the sensing point and the applied loads are calculated. When the estimated and true applied loads were compared, it was confirmed that the vertical and frictional loads can be estimated independently from the circumferential strain with sufficient accuracy. Using this method, one can represent the slip slope curve during driving, which enables the optimization of vehicle control and implementation of a road condition warning system.

The primary forces which determine the dynamic behavior of aircraft are aerodynamic forces generated by pressure differentials acting over the aerosurface areas. In contrast, the primary forces which determine the dynamic behavior of automobiles are friction forces generated by contact pressure acting over the tire-to-road contact areas. It is the tires that transmit the forces that accelerate, decelerate, and maneuver the automotive road vehicle. It is the tires that play a major role in isolating the vehicle, its cargo and passengers, from the shock and vibration effects of road surface irregularities. Last, but not least, the tires play an absolutely critical role in providing vehicle directional stability. What tires do is necessary and very complex, so much so that in nearly 125 years of development no adequate substitute has been found for the pneumatic-elastic rubber and cord structure known as the tire. The tire has prevailed over all those years, undergoing innumerable improvements and refinements, despite still not being fully understood in its mechanisms and behavior. This document attempts to fully explain and understand tire mechanisms and behavior, and is an excerpt from a larger work entitled "Mass Properties and Advanced Automotive Design" presented at the 74th Annual International Conference of the Society of Allied Weight Engineers Inc. in May 2015. That paper, and this excerpt, have undergone considerable revision since then in an ongoing attempt to eliminate all spelling, grammatical, typographical, and other errors.

The purpose of this review paper is to study of effect of the different tire operating parameters on tire performance and review of testing setup to test these tire performance parameters. The testing of tire performance parameters by experimentally is help to designer to correlate the relationships of parameters and to design the tire, hence it is need to testing of tire. Knowledge about dynamic properties of tires is an essential for any kind of research and development activities on vehicle dynamics. The main purpose of laboratory testing is to separate the properties of the tire from the vehicle, achieve high rate of reproducibility and to optimize the cost. This review paper gives the information regarding of different researcher's works on inter laboratory tire testing setup for measuring tire performance parameters and also this review paper helps to understand the factors on which tire performance parameters is depends.

In this paper was developed a theoretical study, underpinning a solution which can be patented, for an adaptive tire, different from the conventional one, which provides, on arable soil, the advantages of a larger contact surface, with quite uniform pressure distribution in the contact patch, such as for rubber belt track. On public roads, this tire is capable to adapt so that the area of contact patch to be minimum and rolling resistance to be minimum. In tire construction is provided a piezoelectric material, which ensures the required energy to power a pressure sensor, located inside the tire and which monitors tire air pressure. Although the estimated cost of achieving such a tire is significantly higher compared to conventional tires, especially if tire production is not of large series, results obtained by simulation and numeric analysis using Finite Element Method are encouraging and they justify the need of such adaptive tire for agricultural trailers.

Engineering Applications of Artificial Intelligence, 2024

Support Vector Regression (SVR) models with different kernel functions (radial basis and polynomial) were developed for predicting deflection and contact area of tubeless and tube-type tractor tyres. Data were collected from experimental trials on 13.6-28 tubeless and tube-type tyres under varying loads (750-1400 kg) and inflation pressures (69-179 kPa). A displacement transducer comprising a rack-pinion arrangement and a rotary potentiometer was developed for measuring tyre deflection. A total of 168 data points were split into 70% for training and 30% for testing the SVR models. An additional 42 new data points were collected at a normal load of 900 kg for validation purpose. As compared to tube-type tyre, tubeless tyre had higher contact area at higher normal loads due to higher tyre deflection. Two SVR models were constructed by considering normal load, inflation pressure, and tyre-type as input parameters. The well-trained SVR model could predict tyre deflection with a maximum deviation of 2% from the measured values as compared to-21% in case of Wulfsohn model. Similarly, the predicted contact area had a maximum variation of 1% from the measured values as compared to 9.99% in case of Komandi model and 31% in case of Diserens model. The sensitivity analysis indicated that the proposed models ranked normal load as the highest priority followed by inflation pressure and tyre-type for estimating both tyre deflection and contact area.

Mobility and Vehicle Mechanics, 2020

One of the most important features of special motor vehicles is the possibility of movement outside the regular roads. In order to provide appropriate characteristics of mobility, such vehicles should, among other things, meet the requirements in terms of geometric parameters of mobility, traction characteristics, characteristics of stability, and the possibility of overcoming obstacles. As the contact between the tire and the road is very important for ensuring proper performance of motor vehicles, significant attention must be paid to it. Keeping this in mind, a model for approximation of average specific pressure between the tire and the deformable surface has been identified in this paper. In the coming period, research that is more detailed should be carried out in order to define similar models for different tires and road surfaces.

Spanish Journal of Agricultural Research, 2015

tor, has a momentous impact on vehicle fuel efficiency. Energy loss in agricultural tires because of inaccurate management has been reported in USA to be about 575 million liters diesel per year (Wulfsohn, 1987). Considering the abovementioned facts, investigating the effect of tire parameters on rolling resistance is a significant issue. Many attempts have been made to explore the rolling resistance analytically, empirically and semi-empirically. Analytical approach is difficult to be interpreted by a tractor driver who should have good mathematical knowledge on the issue. Semi-empirical equations are limited to the prediction of separate performances in driving and braking modes. However, the model of Shmulevich & Osetinsky (2003), which is perfectly adapted for traction and resistance forces in the field, has been successfully verified by the data reported in the literature (Osetinsky & Shmulevich, 2004; Battiato & Diserens, 2013) and by full-scale field experiments.

IOP Conference Series: Materials Science and Engineering, 2020

Being accurately analyses of the dynamics of automotive tires is essential for a wide range of technologies. There are two primary aims of this study: 1. To investigate the use of a Finite Elements Method (henceforth, FEM) in the light-weight truck’ tire (LF3070G1) 2. To implement in Ansys Workbench software in the simulation. Two analyses of the tire dynamics were used. The first analysis was used when the tire is statically balanced between supporting the vehicle weight and the internal air pressure. The second analysis includes the dynamical balance while the vehicle is operating at different weight loads. Each analysis includes two parts. The first part was the mode shapes and the natural frequencies of the tire since it has an influence on the tire’s stiffness and damping constant. The second analysis employed numerical simulations and it was carried out to determine the tire’s time-dependent maximum deformation.

Accurate and efficient tire models for soft soil operations are needed for mobility simulations of wheeled vehicles operating in off-road conditions. The tire model is essential in a vehicle model; the accuracy of the predicted tire forces and moments has a large impact on assessing the vehicle performance, reducing the number of stuck vehicles, avoiding rollovers, and developing advanced control strategies. While finite element method leads to the most detailed tire-soil interaction models, their complexity and extensive computational effort make them less than ideal for the applications envisioned, requiring hundreds of thousands of evaluations. Semi-analytical models such as the F-tire were developed for on-road applications. The semi-analytical soft-soil tire model developed in this study employs a similar construction as F-tire and adds an advanced tire-soil contact model. The tire is discretized in a user-defined number of lumped masses structured in three layers (two for the sidewall, one for the tread and belt), connected by elastic and damping elements connected in various configurations. Simulation results for several case studies performed with the tire model developed in this study are presented. In this paper we also present the experimental work related to soil testing and tire instrumentation and testing, as needed to collect input data and to validate the new off-road tire model. The soil of interest is silty sand. Soil characterization, performed in collaboration with Schnabel Engineering, will be presented. A physical tire has been instrumented with sensors able to collect deflection information in real time. Such information, in addition to the information received from a string potentiometer, is critical in allowing the estimation of the true sinkage (versus just measuring the tire rut). Experimental results obtained for tire deflection with the instrumented tire on a quarter-car test rig will also be presented. Furthermore, since ensuring controlled, repeatable testing conditions is a very important aspect for data collection, the efforts made to guarantee that the normal load applied to the tire will stay constant during testing will also be discussed. The influence of tire and vehicle parameters and soil characteristics on the tire dynamics is also investigated.

2014

In terms of safety and environment, reduction of the noise generated by tire vibrations on a road is very significant. In order to study the vibration properties of vehicle tires, various methods have been presented in literature. In most of these methods, the global structure of tires has been modelled as circular ring, orthotropic plate, periodic or full 3-dimensional models. A brief review of the characteristics of these models and comparison of their dynamic behaviour are the main purpose of the current study. The tire is supposed to be subjected to an excitation caused by contact of the tire and road. Study of vibrational responses demonstrates that the validity of each model is limited to a certain frequency range. To employ the circular ring and orthotropic plate models, first, we require to estimate some structural and material data associated to the nature of these models. To this end, the vibrational response of a 3D model is considered to determine some properties such as...

Journal of emerging technologies and innovative research, 2020

Abstract: It is realized that legitimate abuse of wheel tires are troublesome and it relies upon many affecting elements. Tire expansion pressure has a noteworthy significance on their anxiety conveyance. Tire strain impacts the size of the contact surface with the moving track. Low weight produces a misrepresented flexing of the tire remains, expanding the moving obstruction of the wheel. Too huge weight causes the diminishing of tire bond, sporadic and quicker wear, particularly for the driving wheels. For different soil conditions relying upon the tire pressure, distinctive soil pressure appropriations can be gotten. The paper presents an investigation a model of a wheel tire, by methods for the Finite Element Method. A model of the tire is created utilizing solid works programming.. The investigation was created for different tire pressures. The outcomes and ends got from the investigation are helpful to distinguish the need of any mechanical innovation to keep up vehicle tire P...

1987

Transportation Research Record: Journal of the Transportation Research Board, 2014

Three-dimensional tire-pavement contact loads of two truck tires-a new-generation wide-base tire (WBT) and a dual tire assembly (DTA)were measured and analyzed. Extreme and typical values of tire inflation pressure (552, 690, 758, and 862 kPa) and tire loading (26, 35, 44, 62, and 79 kN) were considered in the experimental program. The measurements were performed with the stress-in-motion Mk IV system at the Council for Scientific and Industrial Research in South Africa. Peak values in three directions were compared, and the importance of tangential contact stresses was highlighted. In addition, characteristic variations of the measurements in the longitudinal, transverse, and vertical directions were identified. A function depending on two regression parameters, applied load, and distance along the contact length was proposed to represent the contact load in the vertical and transverse directions. An analysis was performed on the measurements to obtain the regression parameters, and a simplified procedure was proposed to determine tire-pavement contact loads. The contact area and contact length of the WBTs and the DTA were also compared.

Journal of Terramechanics, 2012

An instrumented drive axle is introduced for a prototype tractor using in field research on tractor and implement performance. This mechanism was developed to determine whether such an instrumented drive axle is practical. The drive axle was equipped with a set of transducers to measure wheel angular velocity, rear axle torque and dynamic weight, as well as tire side forces. Measuring the drawbar pull acting on the tractor provides data for calculating net traction, motion resistance and chassis resistance for each driven wheel.