bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure Loss Mechanisms in Pneumatic Tires
Authors: Dodge R. N. , Clark S. K. , Loo M. 
Published: June 2006

Abstract
An experimental method was developed for the measurement of air permeation leakage through tubeless automobile tires and wheels. A differential pressure measurement system was used with temperature as an independent parameter. The diffusion rates generally far exceeded the loss rates observed through either the valve core or the valve rim seal on several typical tires observed under normal static conditions.
While permeation loss rates vary from tire to tire, typical losses are of the order of 0.5 to 1.0 psi (3.4 to 6.9 kPa) per month at 70° F (21° C) ambient temperature. Losses increase rapidly with increase in temperature to about 1.5 psi (10.3 kPa) per month at 90°F (32°C).
An analytical model was developed which can predict pressure loss rates due to permeation under a variety of climatic conditions.
Study of Causes of Variability in Tire Wear Rates
Authors: Brenner F. C. , Galloway E. 
Published: June 2006

Abstract
Estimates of wear rate ratios for the two tire brands tested vary in replicated experiments run concurrently or after intervals of weeks or months. This study reports tests made on different car models, and repeated several weeks later. Rim width and shock absorber stiffness were also studied for their contribution to wear rate variability. Alignment settings for all cars were fixed at the midpoint of the manufacturer's specification range, and were frequently checked and adjusted if necessary. Hitherto unreported data from former experiments that were run under various controlled alignment procedures are reported here. No evidence was found in the present experiments that differences in car models, rim width, or shock absorber stiffness contribute to wear rate variability. The average wear rates in the several experiments varied by 30%, but the ratios of the tire brands varied by only ± 2.23% around the mid-range. The variations among cars when alignment settings were frequently checked and adjusted were characterized by a standard deviation of less than 0.20 mils/1000 miles (0.008 mm/1000 km).
On the Contact Problem of Tires, Including Friction
Authors: Rothert H. , Idelberger H. , Jacobi W. , Laging G. 
Published: June 2006

Abstract
The mathematical description of tires does not usually consider frictional interaction between the tire and the surface over which it moves. An approach for doing so is presented in the present paper for a homogeneous tire without grooves and which is loaded axially. The tire footprint area is divided into smaller areas that either stick or slide at the interface between the tire and its supporting structure when frictional forces are applied. Discretization of the contact problem into finite elements leads to a nonlinear system of equations for the nodal displacements. The algorithm applied to compute the normal and tangential forces in the contact zone is described. The Newton-Raphson method and the modern quasi-Newton methods BFGS (Broyden, Fletcher, Goldfarb, Shanno) and DFP (Davidon, Fletcher, Powell) proved to be the most effective. Normal and tangential forces in the footprint area were computed by the Lagrange multiplier method or directly by calculation of the stress tensor in the contact zone.
A Model Analysis of Tire Behavior Under Vertical Loading and Straight-Line Free Rolling
Authors: Loo M. 
Published: June 2006

Abstract
A structural analog, consisting of a flexible circular ring under tension with a nest of radially arranged linear springs and dampers, is developed as a pneumatic tire model. The model is concerned with the prediction of the tire's vertical load-deflection characteristics and its free rolling resistance.
The mathematical formulation of the boundary of the model's region of contact with a smooth hard surface is based on approximations made using the theory of a tensioned string supported by an elastic foundation. Forces developed within the contact region are computed from geometrical considerations.
The model's ring tension and radial foundation stiffnesses, as related to the tire's inflation pressure, are obtained experimentally by performing contact patch length measurements and static point-load tests on the specific tire modeled. Further, by prescribing a loss factor in the radial dampers, the model's free rolling resistance characteristics may be computed.
Experimental verification conducted on a radial tire shows general agreement between the predicted and experimental vertical load-deflection characteristics for the normal working range of inflation pressure, deflection, and interacting surface curvature. The predicted rolling resistance characteristics are also found to be in good accord with experimental measurements.
Finite Element Modeling of a Homogeneous Pneumatic Tire Subjected To Footprint Loadings
Authors: Ridha R. A. , Satyamurthy K. , Hirschfelt L. R. 
Published: June 2006

Abstract
In this paper, we use an approach which involves 3D finite elements and a contact algorithm. For a given deflection of the hub, the algorithm computes the nodes that come into contact with a predefined contact plane, and the magnitudes of the contact forces at the nodes. Thus, the algorithm computes the size and shape of the footprint, and the contact forces at the FE nodes. To illustrate the technique, we analyze a homogeneous tire subjected to footprint loading. The computed shapes and sizes of the footprint area at different levels of rim deflection are shown to be in good agreement with experimental results. The computed tire profiles and the load-deflection response of the tire are also in good agreement with experimental results. The computed results include the distribution of stress, strain, and strain energy density within the tire, and the changes in this distribution with applied footprint loadings.
Effect of Tire Tread Pattern on Groove Wander of Motorcycles
Authors: Doi T. , Ikeda K. 
Published: June 2006

Abstract
Water on a road surface can dangerously lower the coefficient of friction of vehicle tires. One way to reduce the water thickness is to cut many “rain grooves” into the pavement parallel to its edges. Such grooves, however, can exert unwanted side forces, particularly on motorcycle tires where driver reaction can cause accidents. This “grove wander” is somewhat related to vehicle geometry, but is more strongly related to interaction between road grooves and tire tread grooves. From studies of this interaction we have developed principles for tread groove design that can be evaluated from relative spacing of tread grooves and pavement grooves, as well as by subjective road tests.
Textile Mechanics Model of a Pneumatic Tire
Authors: Miller C. , Popper P. , Gilmour P. W. , Schaffers W. J. 
Published: June 2006

Abstract
A mathematical model to analyze the structural behavior of a pneumatic tire is described. The model consists of a series of unidirectional layers of tire cord bonded together in a contoured shape to form a laminated structure. The number of cord layers and the properties and orientation of the cords in each layer can be varied to represent various sections such as the belt and sidewall of a radial construction. The model includes only membrane stresses, but permits large deformations and geometric rearrangement of the cords. Inputs to the model include the initial uninflated tire geometry (mold shape), properties and arrangement of cords and rubber, and the applied load distribution. Model outputs include shape, cord tension distributions, and interply shear stresses. A selection of results from the model are presented for a particular radial tire, and a comparison is made between the calculated and experimentally observed shapes. The results are interpreted in terms of the fundamental mechanical behavior of the system.
Analytical Models for the Deformation and Adhesion Components of Rubber Friction
Authors: Schapery R. A. 
Published: June 2006

Abstract
Fourier methods of analysis are employed to develop linear viscoelastic stress and displacement solutions for use in contact problems, and then some exact results for contact area and the deformation component of the friction coefficient are derived for materials whose complex modulus obeys a power law in frequency. A model for predicting waves of detachment resulting from adhesion is proposed, and it is shown that an analogy exists whereby the solution method for sliding without adhesion can be used to predict these waves and the resulting frictional force.
A Note on a New Tire Cord Adhesion Test
Authors: Nicholson D. W. , Livingston D. I. , Fielding-Russell G. S. , Gent A. N. 
Published: June 2006

Abstract
A new tire cord adhesion test is described. The test piece contains two opposite, symmetrically embedded cord ends that are pulled during testing. Failure is initiated at the cord ends and propagates as an adhesive failure until one cord becomes detached. Representative experimental results are given.
A New Tire Cord Adhesion Test
Authors: Nicholson D. W. , Livingston D. I. , Fielding-Russell G. S. 
Published: June 2006

Abstract
A new tire cord adhesion test is reported. Although developed primarily for measuring adhesion of rubber to tire cord, the test is applicable to any cord- or wire-reinforced composite, for example, rubber hose or belting. The specimen is a rubber bar of square cross section containing two partially embedded cord ends opposite each other. Upon the application of sufficient tensile force to the cords, failure is initiated at the tip of the embedded end and proceeds along the cord to the exterior, resulting in pull-out of one of the ends. This result contrasts with the initiation of failure in a specimen of the pull-through type containing a throughgoing cord. In the latter specimen, failure initiates where the cord emerges from the rubber and runs back into the interior.
Failure is adhesive when pull-out occurs. Under special conditions cohesive failure (tear) occurs and the specimen is cleaved transversely. Reproducibility is excellent and the test has high discriminating power. A theoretical equation permits calculation of the energy of adhesion.
Analysis of Rubber Friction by the Fast Fourier Transform
Authors: Schapery R. A. 
Published: June 2006

Abstract
A numerical method for solving contact problems is developed and then used to predict friction (without adhesion) between rubber in plane strain and periodic arrays of parabolic and triangular substrate asperities; the numerical method itself, which is based on the fast Fourier transform algorithm, is not limited to these asperity shapes. Also, effects of superposing two and more scales of texture are described. Some generalizations and related applications, such as analysis of tire traction, are then discussed.
Effect of Slip Rate on the Peak Braking Coefficient of Automobile Tires
Authors: Boyd P. L. , Walston W. H. 
Published: June 2006

Abstract
The peak braking coefficient was measured for five tires at six slip rates on three wet surfaces. In addition, a slick tire was tested on dry asphalt in a similar fashion. The difference in braking coefficient for a tire-pavement combination over the range of slip rate varied from 3.6 to 33.6%. In general, the effect of slip rate was more pronounced with slick tires and low friction surfaces. In cases where statistically significant differences existed on wet surfaces, the highest friction coefficients occurred most often at intermediate slip rates (between 36 and 100%/s), and the lower friction coefficients usually were obtained at both very high and very low slip rates. It is hypothesized that a reduction in the slip rate causes an increase in the peak braking coefficient on a dry surface but increases the probability of partial hydroplaning on a wet surface. The balance between these two conflicting effects causes the peak braking coefficient to be maximum at intermediate slip rates on many wet surfaces.
The Relationship Between Texture and Pavement Friction
Authors: Henry J. J. 
Published: June 2006

Abstract
The transient slip method is shown to be a useful technique to evaluate the speed dependence of pavement friction. From the results of transient slip tests with a standard test tire, it is possible to predict skid resistance, speed gradients, and side force coefficients. Transient slip data can be predicted from wet pavement macro-texture and microtexture and, therefore, skid resistance-speed gradients and side force coefficients can be predicted from texture measurements.
Deformation of the Pneumatic Tire
Authors: Patel H. P. , Zorowski C. F. 
Published: June 2006

Abstract
A finite element model is presented for analysis of axisymmetric static loadings of a bias ply pneumatic tire. The model can predict deformed shapes and the resulting cord forces in the tire. The tire is considered as a thin shell of revolution with membrane and bending stiffness. Its material properties are assumed to be linearly orthotropic. Large axisymmetric deformations studied with the proposed model gave very close approximations to the actual situation. The predicted cord forces matched the experimental values very closely.
Automatic Tread Gaging Machine
Authors: Ludwig G. S. , Brenner F. C. 
Published: June 2006

Abstract
An automatic tread gaging machine has been developed. It consists of three component systems: (1) a laser gaging head, (2) a tire handling device, and (3) a computer that controls the movement of the tire handling machine, processes the data, and computes the least-squares straight line from which a wear rate may be estimated. Experimental tests show that the machine has good repeatability. In comparisons with measurements obtained by a hand gage, the automatic machine gives smaller average groove depths. The difference before and after a period of wear for both methods of measurement are the same. Wear rates estimated from the slopes of straight lines fitted to both sets of data are not significantly different.
Rubber Emissivity and the Thermal State of Tires
Authors: Browne A. L. , Wickliffe L. E. 
Published: June 2006

Abstract
An experimental procedure is described for obtaining accurate values of emissivity for materials of low thermal conductivity such as rubber. This procedure is then used to obtain data for the emissivity of tire tread, white sidewall, black sidewall, and inner-liner surfaces. The significance of these results to infrared (IR) temperature measurement and to the analytical modeling of the thermal state of a tire is discussed.
A Note on Groove Depth Changes Without Wear
Authors: Brenner F. C. 
Published: June 2006

Abstract
Tread wear rates during first wear measured by groove depth and weight changes do not always agree. Sometimes, the groove depth method shows a high rate and the weight loss method a low rate. Reported here are experiments designed to determine if grooves show depth changes without wear.
Four tires were measured before mounting on a wheel, after mounting and inflation, and after inflation and storage. The mounted and inflated tires showed shallower shoulder grooves and deeper center grooves than the unmounted tires. In a second experiment, tires were measured immediately after a tread wear test and then stored mounted for two weeks before remeasuring. Each groove became deeper, and there was no change in the crown radius of any tire.
A Simple Tire Deformation Model for the Transient Aspect of Hydroplaning
Authors: Agrawal S. K. , Henry J. J. 
Published: June 2006

Abstract
When a nonrotating tire moves from a quasi-dry section to a flooded section of pavement, a transition from a nonhydroplaning to a hydroplaning state takes place; during this transition, the tire deforms continuously. With the assumption that each instant during this transition represents an equilibrium state, a tire deformation model is developed. The deformation is computed by modeling a nonrotating tire as a semi-infinite solid, and by replacing the effects of tire inflation pressure and vertical load by a modified elastic modulus. The close agreement between the predicted results from the model and the experimentally measured tire deformation values at a limited number of points on the tire contact surface suggests that the semi-infinite-solid model for the tire deformation computations is a reasonable technique for determining tire elastic behavior under hydroplaning condition.
Parametric Study of Convective Heat Transfer Coefficients at the Tire Surface
Authors: Browne A. L. , Wickliffe L. E. 
Published: June 2006

Abstract
Analyses have shown that the thermal state of a tire is influenced by both the size of and variation in the value of the convective heat transfer coefficient at the tire surface. In the work reported here, a test facility was constructed to permit the determination of convective heat transfer coefficients under a broad range of operating conditions. Data were obtained to show the effects of air speed, boundary layer thickness and turbulence level, humidity, tire surface contamination, tire surface roughness and unevenness, and tire surface wetness on convective heat transfer coefficients. The significance of these results to tire power loss is discussed.
Distribution of Speed and Acceleration on a Tread Wear Course
Authors: Ludwig G. S. , Brenner F. C. 
Published: June 2006

Abstract
Belted bias and radial Course Monitoring Tires were run over the National Highway Traffic Safety Administration tread wear course at San Angelo on a vehicle instrumented to measure lateral and longitudinal accelerations, speed, and number of wheel rotations. The data were recorded as histograms. The distribution of speed, the distributions of lateral and longitudinal acceleration, and the number of acceleration level crossings are given. Acceleration data for segments of the course are also given.
Contouring the Tire Sidewall with Moire
Authors: Browne A. L. 
Published: June 2006

Abstract
Knowledge of the tire sidewall deformation is necessary for accurate modeling of the response of a pneumatic tire to applied forces. An experimental method, the moire fringe technique, is described which permits the contouring of the tire surface under all normal operating conditions. Results are presented for a series of tests which were conducted to determine the tire sidewall deformation due to static loading, centrifugal force, combined vertical and centrifugal loading, and high speed operation (during which standing waves are present in the tire sidewall).
Compression of an Inflated Tube Between Rigid Surfaces as an Elementary Tire Mechanics Model
Authors: Nicholson D. W. 
Published: June 2006

Abstract
An infinitely long membrane tube under lateral compression between various rigid surfaces is used as a model to illustrate the load carrying mechanism in tires. The surfaces include parallel flat plates, indentors, and surfaces which are flat and parallel except for a semicircular hump. Such configurations are relevant to deflection of tires against flat ground, the plunger test of tire behavior, and tire enveloping properties.
In the flat plate case, compression rate appreciably affects both the force-deflection relations and strength. But even at its weakest the structure bursts only at very high deflection. In the indentor case, burst cannot occur unless the initial pressure exceeds a value dependent on the indentor radius to which behavior is otherwise insensitive. Regarding envelopment, the magnitude of the disturbance due to the presence of a hump increases with decreasing tube inflation pressure.
Nondestructive Inspection of Aircraft Tires by Pulse-Echo Ultrasonics
Authors: McConnell G. K. , Klinman R. 
Published: June 2006

Abstract
Recent technological advances in ultrasonic flaw detecting apparatus (broad band characteristic) have shown that ultrasonic pulse-echo inspection of aircraft tires is now possible. The acoustic properties of rubber and rubber composites have been studied so that optimum system requirements may be determined. A prototype inspection system has been constructed to demonstrate the ability of pulse-echo ultrasonics to locate critical internal flaws and structural elements in tires. Electronic and mechanical refinements necessary to complete automated inspection systems are discussed and the importance of defect standards for aircraft tires considered.
Wet Skid Resistance of Car and Truck Tires
Authors: Dijks A. 
Published: June 2006

Abstract
Two test trailers for measuring tire characteristics are described. One of the trailers is specially built for testing car tires and can steer, camber, and brake the test tire. This trailer is provided with a five component measuring hub. The second trailer, for testing truck tires, is restricted to braking only.
Braking forces are measured with a dynamometer. The determination of peak and locked wheel braking force coefficients is discussed. In addition, for car tires, a method for obtaining side force coefficients is given. Test results are given for both car and truck tires showing the influence of road surface texture, speed, and tread depth on skid resistance, and the results are compared.
Analysis of Rim and Belt Constraints on the Forces and Motions of a Tire Model
Authors: Nicholson D. W. 
Published: June 2006

Abstract
A model is proposed for the influence of the rim and the belt on load carrying in tires. It consists of an infinitely long, inflated, thin-walled tube whose cross-sectional geometry is constrained by two rigid plates. The model structure is subjected to a vertical load, a transverse load, and a rotational moment. A general set of equations is derived in terms of one inflation and two geometric parameters. Methods of numerical solution are given which hold whether forces or deflections are the independent variables. Numerical results are given for the case of slow motions and deflections specified.
Comparative Study of Tread Depth Measurement Techniques
Authors: Brenner F. C. , Kondo A. 
Published: June 2006

Abstract
Although there are over 20 organizations in the United States engaged in tread life evaluation by average groove depth measurements, no previous attempt has been made to compare the results obtained by the variety of procedures in use. Therefore, ASTM Committee F-9 on Tires organized an experiment in which four tires were measured at 14 laboratories representing most major tire producers and independent test houses. Each participant measured the tires following his normal practice. In several laboratories the tires were measured by each of their operators.
The data show in general that there are significant differences between laboratories but none between operators within a laboratory. Precision and accuracy vary between laboratories. Practices between laboratories vary greatly with respect to the number and locations at which measurements are made. On ribbed tires, 7 of 14 measured all grooves at 10 positions in each. For snow tires, there was no most common practice.
Fore-Aft Stiffness Characteristics Of Pneumatic Tires
Authors: Dodge R. N. , Clark S. K. 
Published: June 2006

Abstract
A simple mathematical model is proposed for estimating the fore-aft elastic stiffness of pneumatic tires. This model is based upon two idealized solutions, the first being that for the extensional stiffness of a pressurized tube reinforced with inextensible cords, while the second solution is that for the shear deformation of an unpressurized elastic tube. The combination of these two elements allows one to estimate fore-aft stiffness characteristics of pneumatic tires. The validity of the proposed model was tested by static measurements at different inflation pressures of the fore-aft spring rates of four tires varying in size and construction. Additional structural data required for the analytical solution of the model were also obtained from these tires. Comparison of the calculated and experimental results indicates that the trends are generally correct, although close correlation between experiment and calculation is difficult to obtain.