The Three-Dimensional Contact Patch Stress Field of Solid and Pneumatic Tires

1992 ◽  
Vol 20 (1) ◽  
pp. 3-32 ◽  
Author(s):  
M. G. Pottinger
Keyword(s):  
Boundary Condition ◽  
Friction Coefficient ◽  
Stress Field ◽  
Three Dimensional ◽  
Vehicle Control ◽  
Operating Conditions ◽  
Pneumatic Tire ◽  
Contact Patch ◽  
Control Forces ◽  
Pneumatic Tires

Abstract Contact patch (footprint) physics is fundamental to the generation of vehicle control forces, tire and road wear, and tire structural mechanics. Footprint physics depends strongly on tire design, pavement topography, and operating conditions. This paper discusses the three-dimensional contact patch stress field of two generic tire types: solid and pneumatic. The discussion is limited to the comparison of the static and free rolling states of both tire types, examination of the effect of the bead-rim boundary condition in the pneumatic tire, and a brief look at the effect of the friction coefficient and viscoelasticity on the solid tire. The discussion is based on experimental results for a smooth-treaded urethane solid tire and a low-pull-force smooth-treaded radial which are assumed to generally represent solid and pneumatic tires. The results obtained offer significant guidance to those who are attempting to mathematically model tires, understand wear, and comprehend the physics of the tire contact patch.

Force and Moment Characteristics of a Rhombi Tessellated Non-Pneumatic Tire

2016 ◽  
Vol 44 (2) ◽  
pp. 130-148 ◽  
Author(s):  
Anand Suresh Kumar ◽  
Ramarathnam Krishna Kumar
Keyword(s):  
Load Distribution ◽  
Three Dimensional ◽  
Element Model ◽  
Operating Conditions ◽  
Lateral Stiffness ◽  
Contact Pressure Distribution ◽  
Static Behavior ◽  
Pneumatic Tire ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

ABSTRACT There has been a recent spate of activities in the design of non-pneumatic tires (NPTs). The validation of a NPT's design is incomplete unless its performance is compared with an equivalent pneumatic tire. Apart from its static behavior, an evaluation of the tire's performance can be done by observing its force and moment (F&M) characteristics. In the present work, an NPT has been designed with an aperiodic rhombi tessellated spoke acting as the load bearing member, where the “unit cell” design is based on the vertical, circumferential, and lateral stiffness offered by the structure. A three-dimensional finite element model has been used to capture the mechanics of load distribution in the spoke, contact patch, and variation of contact pressure distribution when the tire is subjected to different operating conditions. SIMULIA/Abaqus has been used to conduct static loading, acceleration/braking, and cornering analyses. The F&M characteristics have been extracted from these simulations and compared with those of a 165/70R14 passenger car tire. The variation in the vertical and circumferential stiffness based on the spoke geometry has also been highlighted. The use of conventional pneumatic tire's belts to alter the NPT's lateral stiffness, despite the tire behaving like a “bottom loader,” adds uniqueness to the design. The NPT's capability to match the pneumatic tire's performance and the variability observed in the tire's F&M characteristics reiterate the freedom available in NPT design, thus providing the opportunity to have similar tires with varying performance characteristics.

Experimental Investigation of the Tractive Performance of Pneumatic Tires on Ice

2020 ◽  
Vol 48 (1) ◽  
pp. 22-45 ◽  
Author(s):  
Emilio Jimenez ◽  
Corina Sandu
Keyword(s):  
Surface Temperature ◽  
Normal Load ◽  
Operating Conditions ◽  
Normal Operation ◽  
Inflation Pressure ◽  
Contact Patch ◽  
Ice Surface ◽  
Ice Surface Temperature ◽  
Drawbar Pull ◽  
Pneumatic Tires

ABSTRACT This investigation was motivated by the need for performance improvement of pneumatic tires in icy conditions. Under normal operation, the pneumatic tire is the only force-transmitting component between the terrain and the vehicle. Therefore, it is critical to grasp the understanding of the contact mechanics at the contact patch under various surfaces and operating conditions. This article aims to enhance the understanding of the tire-ice contact interaction through experimental studies of pneumatic tires traversing over smooth ice. An experimental design has been formulated that provides insight into the effect of operational parameters, specifically general tire tread type, slip ratio, normal load, inflation pressure, ice surface temperature, and traction performance. The temperature distribution in the contact patch is recorded using a novel method based on thermocouples embedded in the contact patch. The drawbar pull is also measured at different conditions of normal load, inflation pressure, and ice temperatures. The measurements were conducted using the Terramechanics Rig at the Advanced Vehicle Dynamics Laboratory. This indoor single-wheel equipment allows repeatable testing under well-controlled conditions. The data measured indicates that, with the appropriate tread design, the wheel is able to provide a higher drawbar pull on smooth ice. With an increase in ice surface temperature, a wet film is observed, which ultimately leads to a significant decrease in traction performance.

scholarly journals Analysis of Vertical Stiffness Characteristics Based on Spoke Shape of Non-Pneumatic Tire

2021 ◽  
Vol 11 (5) ◽  
pp. 2369
Author(s):  
Jongkeun Sim ◽  
Jiyeon Hong ◽  
Insu Cho ◽  
Jinwook Lee
Keyword(s):  
Three Dimensional ◽  
Structure Design ◽  
Minimum Size ◽  
Three Dimensional Model ◽  
Pneumatic Tire ◽  
Vertical Stiffness ◽  
Applied Model ◽  
Stiffness Characteristics ◽  
Tire Models ◽  
Pneumatic Tires

Recently, research regarding non-pneumatic tires that are resistant to punctures has been actively conducted, and the spoke structure design of non-pneumatic tires has been found to be a crucial factor. This study aimed to analyze the vertical stiffness characteristics of a non-pneumatic tire based on the shape of the spoke under the application of a vertical load. The three-dimensional model of a commercial non-pneumatic tire was obtained from the manufacturer (Kumho Tire Co., Inc., Gwangju, Korea), and the vertical stiffness characteristics of the three tire models with modified spoke shapes were compared and analyzed based on a reference tire model. Results show that the vertical stiffness of the fillet applied model is most appropriate. Furthermore, the vertical stiffness characteristics of the analyzed tire models indicate that if fillets with a minimum size are applied to the spokes, the stability of the non-pneumatic tire is expected to improve.

Analytical Techniques of Case and Pad for 5-Pad Tilting Pad Bearing

2012 ◽  
Vol 569 ◽  
pp. 620-623
Author(s):  
Min Jae Shin ◽  
Jae Duk Hwang ◽  
Chae Sil Kim ◽  
Soo Yong Cho
Keyword(s):  
Boundary Condition ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Analytical Techniques ◽  
Operating Conditions ◽  
Rotational Degree ◽  
Analysis Techniques ◽  
Actual Operating ◽  
Tilting Pad ◽  
Actual Load

As the pad of a tilting pad bearing has invisible, three dimensional complicated movements around its pivot point inside the bearing case, its contact surface is difficult to establish. The loading points inside the bearing case are also not easy to predict accurately. This paper presents practical analysis techniques and loading conditions for the pad and bearing case of a tilting pad bearing in the structural analysis to meet the actual operating conditions. The analysis for the pad is conducted by applying the pressure of lubricant to the whole pad surface and constraining the circumferential degrees of freedom at nodes around the pivot. Part of the pad of boundary condition is hydraulic of practically applied lubricant and contact area of pivot and the rotational degree of freedom in line with circumferential. It is proposed to using of external case boundary condition 4 pads and 5 pads. Points of the case, combined with the pad are applied to the actual load. The result of analysis, the reliability of the pad and the case was obtained, because stress distribution is nearly identical with the actual phenomenon.

Temperature Rise Times in Pneumatic Tires

1976 ◽  
Vol 4 (3) ◽  
pp. 181-189 ◽  
Author(s):  
S. K. Clark
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Temperature Rise ◽  
Thermal Equilibrium ◽  
Transfer Coefficients ◽  
Pneumatic Tire ◽  
Heat Transfer Coefficients ◽  
Idealized Model ◽  
Pneumatic Tires

Abstract An idealized model is proposed for heating of a pneumatic tire. A solution is obtained for the temperature rise of such a model. Using known thermal properties of rubber and known heat transfer coefficients, the time to reach thermal equilibrium is estimated.

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