The tire-terrain interaction is complex and tremendously important; it impacts the performance and safety of the vehicle and its occupants. Icy roads further enhance these complexities and adversely affect the handling of the vehicle. The analysis of the tire-ice contact focusing on individual aspects of tire construction and operation is imperative for tire industry's future. This study investigates the effects of the tread rubber compound on the drawbar pull performance of tires in contact with an ice layer near its melting point.
A set of sixteen tires of eight different rubber compounds were considered. The tires were identical in design and tread patterns but have different tread rubber compounds. To study the effect of the tread rubber compound, all operational parameters were kept constant during the testing conducted on the Terramechanics Rig at the Terramechanics, Multibody, and Vehicle Systems laboratory. The tests led to conclusive evidence of the effect of the tread rubber compound on the drawbar performance (found to be most prominent in the linear region of the drawbar-slip curve) and on the resistive forces of free-rolling tires.
Modeling of the tire-ice contact for estimation of temperature rise and water film height was performed using ATIIM 2.0. The performance of this in-house model was compared against three classical tire-ice friction models. A parametrization of the Magic Formula tire model was performed using experimental data and a Genetic Algorithm. The dependence of individual factors of the Magic Formula on the ambient temperature, tire age, and tread rubber compounds was investigated. / Master of Science / The interaction between the tire and icy road conditions in the context of the safety of the occupants of the vehicle is a demanding test of the skills of the driver. The expected maneuvers of a vehicle in response to the actions of the driver become heavily unpredictable depending on a variety of factors like the thickness of the ice, its temperature, ambient temperature, the conditions of the vehicle and the tire, etc. To overcome the issues that could arise, the development of winter tires got a boost, especially with siping and rubber compounding technology. This research focuses on the effects on the tire performance on ice due to the variation in the tread rubber compounds.
The experimental accomplishment of the same was performed using the Terramechanics rig at the Terramechanics, Multibody, and Vehicle Systems (TMVS) laboratory. It was found that the effect of the rubber compound is most pronounced in the region where most vehicles operate under normal circumstances.
An attempt was made to simulate the temperature rise in the contact patch and the water film that exists due to the localized melting of ice caused by frictional heating. Three classical friction models were used to compare the predictions against ATIIM 2.0, an in-house developed model. Using an optimization technique namely the Genetic Algorithm, efforts were made to understand the effects of the tread rubber compound, the ambient temperature, and the aging of the tire on the parameters of the Magic Formula model, an empirical model describing the performance of the tire.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/108320 |
| Date | 20 August 2020 |
| Creators | Shenvi, Mohit Nitin |
| Contributors | Mechanical Engineering, Sandu, Corina, Taheri, Saied, Kennedy, Ronald H. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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