Tire Temperatures Research Articles

Analysis of effect on temperature field of tire curing process by initial temperatures and condensate discharging

To improve the heat transfer efficiency and temperature distribution uniformity of steam-heating vulcanization processes, a 3D simulation model was established by Solidworks and transient simulation studies were carried out by Fluent 2021 R1. The effects of four initial tire temperatures and five condensate discharging schemes on the heat transfer efficiency and temperature distribution uniformity were investigated. The study finds that: (1) At the end of the stage of filling the capsule with high-temperature and high-pressure steam, the temperature of the lower mold sidewall is 152.08 °C which is significantly higher than that of the lower mold bead with 128.03 °C, the lower mold shoulder with 115.00 °C, and the lower mold crown with 109.57 °C. (2) With the initial tire temperature increasing from 25 °C to 55 °C, the final temperatures at the lower mold crown and the upper mold sidewall are increased by 12.00 °C and 2.27 °C, respectively, indicating that the increase in the initial temperature helps to raise the temperature at difficult vulcanization locations of the tire. (3) It is recommended to carry out condensate discharging when the volume fraction of condensate at the lower mold sidewall is 0.2 %∼0.3 %, which improves the temperature uniformity in the steam-heating vulcanization process.

Thermomechanical Modeling of Aircraft Tire–Runway Contact for Transient Maneuvers

ABSTRACT The aircraft tire is the link between the aircraft and the runway and transmits forces and moments within the contact area. During ground maneuvers, the tire is exposed to a wide range of operating conditions. The tires support the weight of the aircraft, they ensure safe rolling during taxiing, and they transfer the required forces to the runway during takeoff and landing. Temperature development during these maneuvers is of great importance because temperature can affect both material stiffness and friction behavior as well as wear characteristics. Heat is generated inside the tire due to energy dissipation caused by the cyclic loading of the tire during rolling. In addition, heat is generated due to friction in the tire–runway contact. Experimental measurements of the temperature distribution in the entire tire are not yet possible. The tire temperatures can only be determined at selected critical spots. Simulation models can help to obtain a better understanding of the overall tire temperature distribution during transient maneuvers. In this work, the transient thermomechanical processes of a rolling aircraft tire, e.g., directly following the touchdown process or during taxiing, are modeled based on a simple physical tire model. An extended brush model is used to simulate the contact forces. The tire temperature is determined via the transient heat conduction equation in radial and circumferential directions. The mechanical and thermal models are coupled via the coefficient of friction and the sliding velocities in contact. The free model parameters are parameterized using experimental data, and the overall model is validated by measurements on the whole tire. The validated thermomechanical tire model is used for simulations or the analysis of different driving maneuvers to get a better understanding of the temperature development in the aircraft tire.

Snow-Covered Tires Generate Microhabitats That Enhance Overwintering Survival of Aedes albopictus (Diptera: Culicidae) in the Midwest, USA.

The Asian tiger mosquito, Aedes albopictus (Skuse), is a public health threat because it can potentially transmit multiple pathogenic arboviruses, exhibits aggressive diurnal biting, and is highly invasive. As Ae. albopictus moved northward into the United States, the limits of expansion were predicted as locations with a mean January temperature warmer than -2.5°C. We postulated that the range of Ae. albopictus could exceed these temperature limits if eggs in diapause overwinter in tires that provide an insulating effect from extreme temperatures. Fifteen tires with Ae. albopictus and Aedes triseriatus (Say) eggs, a native cold hardy species, were placed outside at five locations along a latitudinal gradient in Wisconsin and Illinois during the winter of 2018-2019; notably, in January 2019, a regional arctic air event brought the lowest temperatures recorded in over 20 yr. External and internal tire temperatures were recorded at 3 hr intervals, and egg survival was recorded after six months. Aedes albopictus eggs survived only from tires at northernmost locations. The mean internal January temperature of tires that supported survival was -1.8°C, while externally the mean temperature was -5.3°C, indicating that tires provided an average of +3.5°C of insulation. Tires that supported egg survival also had over 100 mm of snow cover during January. In the absence of snow cover, tires across the study area provided an average +0.79°C [95% CI 0.34-1.11] insulation. This work provides strong argument for the inclusion of microhabitats in models of dispersal and establishment of Ae. albopictus and other vector species.

Temperature influence on tire/road noise measurements: recently collected data and discussion of various issues related to standard testing procedures

Air, road, and tire temperatures substantially affect tire/road noise emission. For measuring purposes, one would like to normalize measurements to a reference temperature by means of a reliable correction procedure. Current studies show that temperature effects remain an important source of uncertainty in tire/road noise measurements and tire testing, even after applying the correction terms provided in the various standards. This seems to be the case for the measurement methods used in OBSI, CPX, SPB, and various regulations or directives based on ECE R117. This paper examines a new dataset consisting of 7.5 million temperature measurements aimed at contributing to a better understanding of temperature effects and the ways they relate to air, road, and tire temperatures. It is assumed that tire temperatures are the most relevant for noise corrections; therefore, special studies are made for how tire temperatures relate to air and road (test surface) temperatures. A profound analysis is provided on how these relationships vary over different day times, seasons, and climatic regions. Based on this analysis, the authors provide suggestions for improvement of temperature normalization in current tire/road noise and tire testing standards. Special considerations are devoted to measurements on test tracks having ISO 10844 reference surfaces.

Reducing Whole-Body Vibration Transmitted to Taxi Drivers and Occupants of Peugeot 405 by Providing Optimal Tire Inflation Pressure

This study aimed to reduce WBV transmitted to taxi drivers and occupants of Peugeot 405 by providing optimal tire inflation pressure. This experimental study was carried out on Peugeot 405 taxi manufactured by Iran Khodro Co. in Iran. Vibration characteristics were measured three times, in combined statuses of tire inflation pressure, type of gas used to inflate tires, presence or absence of tubes in tires, and car speed, according to ISO 2631-1 using SVAN 958A as a vibration analyzer with a calibration certificate. Tire temperature was also measured using an IR BE550 thermometer in each combined status. Then, the data were analyzed. The results showed an A (8) value of 0.99 (m / s2) at a tire inflation pressure of 30 PSI for Peugeot 405. The A (8) value decreased with reducing tire inflation pressure (P value<0.001). The A (8) value at an inflation pressure of 28 psi was reported to be 21% lower than that at an inflation pressure of 30 psi. There was an inverse correlation between tire temperature and tire inflation pressure (P value<0.001). The average tire temperature increased with reducing tire inflation pressure. However, no significant difference was found between the mean tire temperatures at tire inflation pressures of 28 psi and 30 psi (P value<0.05). In general, there were significant differences between tire temperatures at tire pressures below 28 psi compared with those at pressures above 28 psi, and higher tire temperatures were reported at pressures below 28 psi. The study results showed that the exposure of Peugeot 405 taxi drivers to WBV exceeds the permissible limits and it can be reduced below the permissible limits by providing a tire inflation pressure of 28 psi. A tire inflation pressure of 28 psi is recommended to replace the pressure recommended by car makers (30 psi).

Effects of Tire Pressures and Test Temperatures on Permanent Deformation of Direct Coal Liquefaction Residue Mixture

This main objective of this research is to investigate the permanent deformation of the asphalt mixtures added direct coal liquefaction residue (DCLR) under various tire pressures and temperatures. Three types of asphalt mixtures, including control/DCLR /composite-DCLR modified asphalt mixture, were prepared by the Marshall design procedure. The rutting test was conducted under various tire pressures changing from 0.7 MPa to 1.0 MPa with a 0.1 MPa interval and at temperatures varying from 55oC to 70oC with a 5 oC interval. Moreover, the dynamic stability and rutting depths were obtained to evaluate the resistance of permanent deformation withthree types mixtures. It was found that the rutting resistance of three mixtures declines with the increased tire pressures and temperatures at various rates. The mixture containing DCLR present has a lower rutting depth and higher dynamic stability compared to the control group asphalt mixture under the conditions. Furthermore, the rutting resistance of composite-DCLR added asphalt mixture is better than that of DCLR modified asphalt mixture. It indicates that the DCLR is favorable for the improvement of rutting resistance. Moreover, the ANOVA was applied, in which analysis results showed that the parameter of the temperature is more sensitive than the tire pressure. Based on the least square procedure, the relationship between dynamic stability and rutting depths is obtained, and the accuracy of the prediction is acceptable.

Numerical evaluation of the temperature field of steady-state rolling tires

Rubber is the main component of pneumatic tires. The tire heating is caused by the hysteresis effects due to the deformation of the rubber during operation. Tire temperatures can depend on many factors, including tire geometry, inflation pressure, vehicle load and speed, road type and temperature and environmental conditions. The focus of this study is to develop a finite element approach to computationally evaluate the temperature field of a steady-state rolling tire. For simplicity, the tire is assumed to be composed of rubber and body-ply. The nonlinear mechanical behavior of the rubber is characterized by a Mooney–Rivlin model while the body-ply is assumed to be linear elastic material. The coupled effects of the inflation pressure and vehicle loading are investigated. The influences of body-ply stiffness are studied as well. The simulation results show that loading is the main factor to determine the temperature field. The stiffer body-ply causes less deformation of rubber and consequently decreases the temperature.

A System to Measure Both Inner and Outer Car Tire Temperatures “in situ”

In the paper, a system for the complex analysis of the internal and external tire temperatures and pressure of sporty tires is presented. Tests were performed on the test circuit of a tire producer. The CTPA 05 measuring system (complex temperature-pressure analyzer) enables simultaneous measurements of the internal temperature and pressure in a passenger or sports tire. The experimentalist determines that the CTPA 05 can be used to measure independently the external temperature of the overcoat on the front wheel driving tires at three points. Measurements of both the internal tire temperature and pressure, as well as of the external tire temperature, are collected together with GPS (global position system) data. The system of measurement is fully automatic and contactless. The obtained results are in very good agreement with those obtained by independent methods.

Flat versus Curved Contact Surfaces Effect on Consumer P-Metric and LT Tire Operating Temperatures

Abstract Rolling stress and resultant operating temperature is critical to the endurance of a tire. There are fundamental differences between the tire stresses when operating on a flat surface, as experienced in normal highway use, and on a cylindrical laboratory test wheel. Even though there are substantially higher tire stresses and temperatures on a curved test wheel, nonetheless, cylindrical road wheels are widely used with the industry for tire endurance testing. Therefore, it is important to consider the severity of test conditions intended for a flat surface and the equivalent severity on the curved surface in order to avoid subjecting the tire to unrealistic stresses and temperatures. In this study, temperature measurements were made at the tire belt edge and centerline, for both flat and curved surfaces, under designed ranges of load, pressure, and speed conditions. Statistical regression models that predict the temperatures at the tire centerline and belt edge locations are developed and discussed. A simple yet consistent conversion from flat to curved conditions is provided so that equivalent tire temperatures are obtained. Flat highway conditions are derived that are temperature equivalent solutions to each of the FMVSS139 step test conditions.

A Finite Element Algorithm for the Prediction of Steady-State Temperatures of Rolling Tires

Abstract A review of the literature on the numerical techniques used for the determination of tire temperatures shows that many attempts have been made to simulate tire temperatures with axisymmetric geometry through a simple decoupled representation of the total thermomechanical behavior. The deformation models used in these studies are primarily statically loaded tires with centrifugal forces to simulate tire-rolling behavior at different speeds. These techniques are usually limited to axisymmetric tires, which make the models applicable to only smooth or circumferential grooved tires. In this study, a finite element (FE) algorithm is developed using Petrov-Galerkin Eulerian technique in cylindrical coordinates. An objective of this approach is to provide a technique that is more appropriate for extension to nonaxisymmetric tires with tread patterns. The developed algorithm has been implemented for the prediction of three-dimensional operating temperatures for axisymmetric tires through a simple decoupled procedure. An iterative procedure is used to determine that the equilibrium temperatures, as loss modulus properties, are functions of strain and temperature. The experimental techniques required to determine tire operating temperatures are fairly involved and highly sophisticated. Therefore, the computation results of the developed algorithm for a smooth treaded tire are compared with the results obtained from a standard FE solver.

Tire Temperature Measurements for Validation of a New Rolling Resistance Model

Rolling resistance of inflated tires contributes greatly to the total load and fuel consumption of heavy vehicles. Correct modeling of rolling resistance is hence very important in order to be able to predict fuel consumption and emissions by computer simulations.Traditional models for rolling resistance are normally only valid under steady state conditions. A new model with improved transient characteristics has been derived in previous work. In this work the temperature dependent part of the adopted model is evaluated by experiments on a heavy truck tire. The measurements have been carried out on both a chassis dynamometer as well as on a truck in actual driving. The temperature has been measured on several positions inside the tire and in the encapsulated air. The results show very good repeatability indicating that tire temperature is an appropriate input to the model. The temperature rise due to a change in velocity shows an exponential relation to time, which corresponds to the new model. The study has been carried out for a number of different velocities and vertical loads. The results show that the temperature model can accurately capture both load and speed dependence. The study clearly shows that the model is able to reproduce tire temperatures measured on a truck driving on real roads with very good accuracy.

A Simple Method of Handling Thermomechanical Coupling for Temperature Computation in a Rolling Tire

Abstract The thermomechanical analysis of a pneumatic tire is a highly complex process due to the effects of temperature on both the mechanical state and the viscoelastic energy dissipation in the tire. This coupled thermomechanical behavior typically requires that rolling tire temperatures be determined iteratively. As a result, a steady-state analysis involves updating the temperature dependent elastic and viscoelastic properties as the solution proceeds. The process is further complicated in a non-steady-state analysis where material properties need to be updated at multiple intervals in time. A simplified method is proposed. First, the sensitivity of the tire elastic response of the tire to changes in material stiffness is characterized using the “deformation index”. Then, using a commercial finite element program and an appropriate user subroutine, heat generation is expressed as a function of the local temperature using a simple algebraic expression involving the temperature dependent material properties and the deformation indices. Temperatures are computed using the finite element program with the coupling information contained in the user subroutine. The result is a simplified method for a fully coupled thermomechanical analysis of a tire for steady-state and transient thermal analysis. The accuracy and the simplicity of the method are demonstrated using a small “tire-like” model. The simplified method is compared to the fully coupled iterative method for a steady-state thermal solution.

Characterization of Tire Emissions Using an Indoor Test Facility

Abstract A tire emission facility has been built in which several tire-wear modes can be simulated while the gaseous, airborne particulate, and sedimentary particulate emissions are collected. The facility was shown to produce tire temperatures and wear rates typical of operating tires. This approach to tire-emission research has many advantages over previous attempts to study tire emissions. The emission rate of gases and airborne particulate matter was nearly independent of wear rate and accounted for only 1–20% of the total emissions. The balance of the emissions were large particles which would be expected to settle on or very close to roadways. Chemical analysis of these large particles showed that approximately 30% of the SBR is unvulcanized, compared to only 1–2% in the tread. The total organic content of the particles was unchanged. This degradation of the rubber leads to enhanced oxygen absorption rates. However, the full significance of the increased rate of oxidation is not known.

A Technique for Evaluating the Hysteresis Properties of Tire Cords

Abstract A slow speed cyclic test has been developed to evaluate tire cord hysteresis properties. Programmed stress variations on an Instron were used to simulate the magnitude and sequence of cord stresses in a running step-loaded tire and relationships were formulated to approximate the dependence of cord heat generation on tire loads, air pressures, and temperatures. The test assumes that tire air pressure imposes a peak stress on cords and that increasing loads on a running tire cause increasing intermittent cord stress relief. Nearly linear relationships result between the log of work loss and the extent of stress relief, which affords a means of comparing cord hysteresis properties over a range of simulated tire loads. The validity of the slow speed results was verified at laboratory test speeds comparable to those encountered in normal tire use. Results generally agreed with long standing qualitative observations of tire cord performance. Commercial PET and nylon greige cords were used for test development and other cord materials, both greige and dipped, have been evaluated. A range of hysteresis properties was obtained on variations in polyester cords.