The properties of rubber have allowed it to be utilized across many different industries. One of the industries that use rubber is the tire industry. The rubber used in tires affects the performance of the vehicle such as its fuel consumption and safety. Hence, study on tire performance becomes important from different aspects. This study will look at the calculation of the friction coefficient of tire rubbers, which affects vehicle safety, based on studies conducted by different research groups. By combining different models, we suggest a new simple model to predict the friction coefficient. Several discussions in the article will be for validation of the model and its range of applications. We then implement a parametric analysis to determine which factors critically affect the friction coefficient. By finding the sensitivity of the inputs of the model/code, the critical factors can be identified and focused on. The parameters that are studied are the storage modulus, loss modulus, surface asperities heights, the surface asperities wavelength, and the adhesive contribution to friction. The adhesion and hysteresis contributions to the friction coefficient are also discussed in this article. It is shown that the adhesive contribution plays a large role in determining the friction coefficient.
Dielectric relaxation and viscosity data are presented for glycerol as a function of pressure and temperature. Viscosity data are given over a temperature range +10°C to —10°C and over a pressure range of atmospheric to 4000 kg/cm2. Dielectric data are given at —6.7°C over the same pressure range. The form of the pressure dependence of the dielectric relaxation time appears to be Arrhenius and that of the viscosity is approximately Arrhenius. However, the pressure dependences of the dielectric time and the viscosity are significantly different, the ratio of ηs to τD varying by approximately two over the pressure range studied. The pressure dependence of ηs and τD were examined according to both the free volume theory of Williams, Landel, and Ferry (WLF) and the hole theory of Eyring. Both theories fail to give the proper pressure dependence of the data. When the WLF theory is applied to the data, the resulting form of the pressure dependence of ηs is incorrect. Although the hole theory of Eyring predicts the correct form of the pressure dependence, a strongly temperature-dependent hole volume, with a negative temperature coefficient of expansion, is needed to fit the experimental data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.