ASTM Radial Medium Truck Tire Operating Temperatures—Curved versus Flat Surfaces2

2008 ◽  
Vol 36 (2) ◽  
pp. 82-107 ◽  
Author(s):  
T. M. Ruip
Keyword(s):  
Motor Vehicle ◽  
Test Surface ◽  
Test Conditions ◽  
Truck Tire ◽  
Truck Tires ◽  
Model Predictions ◽  
Endurance Testing ◽  
Operating Temperatures ◽  
Haul Truck ◽  
Speed Response

Abstract This paper reports the results of an extensive design of experiment (DOE) conducted on radial medium truck tires by the ASTM Committee F09.30 Task Group on Truck/Bus Tire Test Development. These results are from Phase I of the task group’s work, operational (“real world”) tire temperature benchmarking. DOE variables were tire inflation, load, and speed. Response temperatures from embedded thermocouples were measured at apex/ply ending, no. 2/no. 3 belt ending, and shoulder and centerline ribs. Steady-state temperatures for steer, drive, and trailer tires from three different test venues are compared, i.e., flat belt lab machine, road/track, and 1.7 m diam laboratory roadwheel. Results from temperature regression modeling are discussed. Examples of the effects of a curved test surface on tire operating temperatures as well as on tire strain levels are provided. Model predictions are used to compare temperatures and strains of tires running at current Federal Motor Vehicle Safety Standard (FMVSS) 119 test conditions versus a severe service long-haul truck operating condition. The concept of “highway speed equivalency” for laboratory endurance testing is proposed.

Truck Tire Operating Temperatures on Flat and Curved Test Surfaces

2005 ◽  
Vol 33 (3) ◽  
pp. 156-178 ◽  
Author(s):  
T. J. LaClair ◽  
C. Zarak
Keyword(s):  
Flat Surface ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Load Pressure ◽  
Truck Tire ◽  
Endurance Testing ◽  
Operating Temperatures ◽  
The Impact ◽  
Tread Rubber ◽  
Cylindrical Test

Abstract Operating temperature is critical to the endurance life of a tire. Fundamental differences between operations of a tire on a flat surface, as experienced in normal highway use, and on a cylindrical test drum may result in a substantially higher tire temperature in the latter case. Nonetheless, cylindrical road wheels are widely used in the industry for tire endurance testing. This paper discusses the important effects of surface curvature on truck tire endurance testing and highlights the impact that curvature has on tire operating temperature. Temperature measurements made during testing on flat and curved surfaces under a range of load, pressure and speed conditions are presented. New tires and re-treaded tires of the same casing construction were evaluated to determine the effect that the tread rubber and pattern have on operating temperatures on the flat and curved test surfaces. The results of this study are used to suggest conditions on a road wheel that provide highway-equivalent operating conditions for truck tire endurance testing.

Natural Rubber Compounds for Truck Tires

1985 ◽  
Vol 58 (4) ◽  
pp. 740-750 ◽  
Author(s):  
D. Barnard ◽  
C. S. L. Baker ◽  
I. R. Wallace
Keyword(s):  
Stearic Acid ◽  
Heat Generation ◽  
Rolling Resistance ◽  
Synthetic Compound ◽  
Wear Performance ◽  
Test Pieces ◽  
Truck Tire ◽  
Truck Tires ◽  
Rubber Compounds ◽  
Lower Severity

Abstract An 80 NR/20 BR truck tread compound containing a semi-EV cure system and modified with a 6.0 phr level of stearic acid has been shown to exhibit excellent resistance to reversion when compared to a similar compound containing a normal 2.0 phr level of stearic acid. Improvements in the retention of laboratory abrasion resistance, heat generation, and most physical properties have been identified on test pieces subjected to typical truck retread overcure conditions. In highway fleet testing trials of 1100 × 22.5 truck retreads fitted to both third and fourth drive axles of tipper trucks, the modified compound displayed a 42% improvement in treadwear performance over the normal compound in the lower severity third axle positions while performance in the higher severity fourth axle positions was inferior by 20%. In comparison to a 55 SBR/45 BR truck tread, both NR compounds displayed superior wear performance on the fourth axles while some further adjustments of the modified compound are required to match the synthetic compound on the third axles. The reversal of wear performances for all compounds between third and fourth axles is due to the different abrasion mechanisms encountered. Laboratory abrasion rankings do not correlate with wear performances of compounds on the fourth drive axle of trucks, but they do correlate with wear performances on third drive axles. Despite the reversion characteristics of the normal semi-EV compound, no significant adverse effect on treadwear performance was evident at the start of tire life. The low heat generation of the modified compound in laboratory tests is confirmed in actual tire testing. Advantages in rolling resistance characteristics are also evident for the modified compound. Current studies at MRPRA suggest that further modifications of cure system design, in combination with the optimization of NR/BR ratios and mixing methods, will potentially provide NR dominant truck tread compounds which will exhibit superior wear performance in both the higher and lower abrasion severities encountered in heavy-duty truck tire service conditions.

Tire Rolling Resistance from Whole-Tire Hysteresis Ratio

1992 ◽  
Vol 65 (2) ◽  
pp. 444-452 ◽  
Author(s):  
P. S. Pillai ◽  
G. S. Fielding-Russell
Keyword(s):  
Rolling Resistance ◽  
Simple Equation ◽  
General Applicability ◽  
Full Size ◽  
Truck Tire ◽  
Truck Tires ◽  
Wide Range

Abstract A simple equation for tire rolling resistance in terms of whole-tire hysteresis ratio, tire load, and footprint dimensions has been developed from energetic considerations. The rolling resistances of a number of radial passenger and truck tires have been calculated using the equation, and the calculated values were successfully compared with the measured results. The general applicability of the equation was illustrated by predicting the rolling resistances of a wide range of tires—from an experimental HR78-8 minitire to a full size 11R24.5 truck tire.

Through-Plane Water Distribution in a Polymer Electrolyte Fuel Cell at Various Operating Temperatures

2010 ◽  
Author(s):  
Yun Wang ◽  
Ken S. Chen
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Water Distribution ◽  
Electrochemical Reaction ◽  
Neutron Imaging ◽  
Polymer Electrolyte Fuel Cell ◽  
Two Phase ◽  
Model Predictions ◽  
Higher Temperature ◽  
Operating Temperatures

A multi-dimensional mathematical model is formulated for simulating the transport and electrochemical reaction phenomena in a polymer electrolyte fuel cell (PEFC). The model describes the two-phase flows, electrochemical reaction kinetics, species transport, and heat transfer, as well as their intrinsic couplings within a PEFC. Two-dimensional model predictions are computed for the two typical operating temperatures at 40 and 80 °C. Computed results reveal that liquid water level may be lower at the higher temperature operation due to water vapor phase diffusion. Detailed water and temperature distributions are displayed to explain the water and heat transport and their interaction. The computed water-content profiles are compared with available experimental data obtained by neutron imaging.

A novel evaluation on rolling resistance characteristics of truck tire through the simplified experimental modal analysis

2020 ◽  
Vol 234 (12) ◽  
pp. 2771-2782
Author(s):  
Chengwei Zhu ◽  
Jingjing Yan ◽  
Ye Zhuang ◽  
Xueliang Gao ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Evaluation Method ◽  
Single Point ◽  
Rolling Resistance ◽  
Damping Characteristics ◽  
Truck Tire ◽  
Truck Tires ◽  
Half Power ◽  
Resistance Coefficients ◽  
Correlative Relationship

A novel evaluation method for the rolling resistance characteristics of truck tire is proposed, in which a simplified modal experiment is suggested through a single-point vibration sampling from the tire surface with a polyvinylidene fluoride (PVDF) piezoelectric film. Three truck tires are utilized in the modal experiments, and the half-power bandwidth method is employed to identify the damping characteristics of the three tires. The damping characteristics of the tires are ranked by their values. These values are compared with their corresponding rolling resistance coefficients to manifest their correlative relationship. The experimental results, which are obtained from the modal experiment and the rolling resistance test, indicate that the modal parameters and the half-power bandwidth of the tire are exactly correlated to the rolling resistance coefficients. Furthermore, the damping ratios of the tires are correlated well with the rolling resistance coefficients among the tires. Overall, the proposed evaluation method could effectively evaluate the rolling resistance characteristics of the tire, which enable it to be a simple and economical alternative over the conventional tire rolling resistance experiments.

Transient Properties of Truck Tires on Real Road Surfaces

1987 ◽  
Vol 15 (3) ◽  
pp. 188-197
Author(s):  
R. Weber ◽  
M. Münster
Keyword(s):  
Frequency Response ◽  
Phase Angle ◽  
Lateral Force ◽  
Force Response ◽  
Heavy Duty ◽  
Time Rate ◽  
Heavy Duty Truck ◽  
Truck Tire ◽  
Truck Tires ◽  
Road Surfaces

Abstract The cornering, or lateral force response of heavy-duty truck tires, has been evaluated on real road surfaces at speeds of 10–60 km/h. The special mobile truck tire dynamometer has a two-test-tire carriage mounted just ahead of the rear support tires of an articulated truck (tractor) trailer. Equal slip angles may be applied simultaneously to both test tires. The frequency response was evaluated by typical phase angle methods. The phase angle (lag of lateral force behind instantaneous angle) increased with frequency (time rate of application of angle) and decreased with increasing speed.

Predictive Indoor Wheel Testing of Heavy Duty Truck Tires

1987 ◽  
Vol 15 (1) ◽  
pp. 58-67
Author(s):  
R. L. Keefe
Keyword(s):  
Load Transfer ◽  
High Stress ◽  
High Load ◽  
Heavy Duty ◽  
Low Speed ◽  
Service Failures ◽  
Heavy Duty Truck ◽  
Truck Tire ◽  
Truck Tires ◽  
Load Tests

Abstract An indoor wheel test for heavy duty truck tires has been developed to predict in-service failures of commercial and developmental tires. The test, run at slow speed and high load to emphasize stress and fatigue rather than heat, is based on the premise that repeated high stress is the principal cause of in-service tire failure. These stresses occur when dynamic or transient overloads are caused by road bumps, load transfer during braking and cornering, or dual tire configuration on non-uniform surfaces. Although these overloads may occur infrequently, they can become very significant in the long distances run by truck tires. Other current heavy duty truck tire tests are generally run at higher speeds, emphasizing heat resistance of rubber compounds, or else are low-speed, much-overloaded bead tests which are unrealistically severe. Since its development in 1974 the present test has been broadly predictive for many belt, carcass, or fatigue related in-service failures of both bias and radial commercial and developmental truck tires. The test is called “The DuPont High Load Wheel Test” to distinguish it from other low-speed-high-load tests.

Viscoelastic Properties of Truck Tire Compounds and the Related Heat Build-Up

1972 ◽  
Vol 45 (1) ◽  
pp. 1-9
Author(s):  
P. Kainradl ◽  
G. Kaufmann
Keyword(s):  
Multiple Regression ◽  
Viscoelastic Properties ◽  
Loss Factor ◽  
Truck Tire ◽  
Rubber Compounds ◽  
Minimum Residual ◽  
Shoulder Region ◽  
Rubber Coating ◽  
Heat Build Up ◽  
Operating Temperatures

Abstract Rubber compounds used in the manufacture of tread-cap, tread-base, and for the rubber-coating of the rayon cord for 12.00–20 tires have been varied in composition and, in consequence, their viscoelastic properties have been altered. Operating temperatures, in test-wheel runs, have been measured in the shoulder region of the tire close to the casing, using a needle-thermocouple. Multiple-regression has been used to investigate which combinations of viscoelastic properties of the rubber vulcanizates would give a linear, significant correlation to the heat build-up in the tire with a minimum residual. From the nature of the variables in the regression functions, conclusions have been drawn on the type of load occurring in the different components of the tire. It was found that the tread cap contributed to the heat build-up according to its loss compliance E″/|E*|2 and the carcass according to its loss-factor, E″/E′. Thus, the statistics show that the greater contribution to the heat build-up comes from the tread-base, according to its loss-factor also. The values of temperatures, calculated by the multiple-regression, show deviations of only a few degrees centigrade compared to the average temperatures of tires of the same construction. Therefore the operating temperatures of tires to be expected as a result of the compound variations can be estimated in advance. On individual tires greater deviations, up to 10°C, have been measured. These are due to inevitable inaccuracies in tire building and errors in temperature measurements.

scholarly journals DOWNSCALING EFFECTS ON MODELLING WAVES, TIDES AND STORM SURGE

2011 ◽  
Vol 1 (32) ◽  
pp. 33 ◽  
Author(s):  
Yongping Chen ◽  
Shunqi Pan ◽  
Judith Wolf ◽  
Yanliang Du
Keyword(s):  
Storm Surge ◽  
Surface Wind ◽  
Local Domain ◽  
Test Conditions ◽  
South West ◽  
Eastern Atlantic Ocean ◽  
North Eastern ◽  
Model Predictions ◽  
Wave Heights ◽  
The Uk

This paper presents the results of downscaling effects when modelling waves, tides and storm surge using a nested modelling system. In this study, the coupled POLCOMS/ProWAM models are used, with 3 nested computational domains, the largest of which covers part of north-eastern Atlantic Ocean with a coarse resolution grid and the smallest covers the surrounding waters of south-west Cornish coast of the UK with a finer resolution grid. Applying the identical surface wind forcing to all 3 computational domains and the wave and tide boundary conditions provided from the coarse to finer domains, the computed wave heights, tides and surge levels are examined at selected locations to study the downscaling effects. The results show that downscaling could considerably increase accuracy of model predictions in the local domain. For the particular test conditions used in the present study, 3-level and 2-level downscaling produces similar results in the local domain. The results also indicate that downscaling with reduction of grid resolution by 6 times is acceptable for the study site.

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