Please use this identifier to cite or link to this item: http://nopr.niscair.res.in/handle/123456789/7230
Title: Inflation pressure effect on whole tyre hysteresis ratio and radial spring constant
Authors: Pillai, Padmanabha S
Issue Date: Apr-2006
Publisher: CSIR
IPC Code: G01L17/00, B60C
Abstract:  The basic equation for rolling loss R in terms of the whole tyre hysteresis ratio h is modified by incorporating tyre radial stiffness K and rewritten as R = L2 (h/K). (w/A), where w and A are footprint dimensions. Tyre inflation pressure p influences the magnitude of h and K. The primary objective of the present study is to obtain quantitative expressions relating h versus p and K versus p. Three P195/75R14 size radial tyres are selected for the present investigation. The h and K values of these tyres are measured as a function of p and analyzed by invoking two limiting structural terms, viz., structural hysteresis ratio h(0) and structural radial stiffness K(0). The empirical relation between h and p is found to be inversely related as h = k (1/px). The h(0) values are about 0.38, 0.27 and 0.28 for tyres 1, 2 and 3. The hysteresis ratio reduction factor h(f) is normalized with respect to h(0) and is found to be about 78% of h(0) value of the respective tyre. The K term is partitioned into structural stiffness K(0) and inflation pressure stiffness K(). The K(0) values are about 60, 25 and 67 N/mm respectively. The K versus p relation can be expressed as K = K(0) + m.p. = K(0) + K(). The pressure stiffness K() is directly proportional to p as K() = 0.56.p. These empirical equations with experimentally determined fitting coefficients k, ϰ and m for the three P195/75R14 tyres are presented. This study indicates that the tyre size primarily controls the magnitude in reduction of h, through h(f), and the increase in K, through K(), with p. The total tyre load of 5337 N is separated into structural load and pressure load; the former load has a direct relationship with R while the latter has an inverse relation. This is a new analytical approach relating tyre load and rolling loss.
Page(s): 110-116
URI: http://hdl.handle.net/123456789/7230
ISSN: 0975-1017 (Online); 0971-4588 (Print)
Appears in Collections:IJEMS Vol.13(2) [April 2006]

Files in This Item:
File Description SizeFormat 
IJEMS 13(2) 110-116.pdf93.85 kBAdobe PDFView/Open


Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.