Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 01 Dec 2011

Directionality of Tangential Force Variation in High Speed Uniformity

Page Range: 256 – 269
DOI: 10.2346/1.3672823
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Abstract

Tire nonuniformity may affect vehicle ride comfort quality especially while vehicles are running at highway speeds. Spindle force variations in the radial, tangential, and lateral directions are normally used as parameters evaluating tire high speed uniformity performance. An interesting physical phenomenon—directionality of tangential force variation has been observed for many tires. The directionality of tangential force variation means that tangential force variation is different when a tire is measured in the clockwise and counter-clockwise directions under the same test conditions. In this paper, a theory is developed to explain the interesting physical phenomenon. Simulation and analysis are conducted using a dynamic tire model. It is found that the directionality of tangential force variation is caused by the interaction of different types of nonuniformities in tires such as mass and geometry variations.

Keywords: tire nonuniformity; vibration; vehicle ride comfort; tangential force variation; high speed uniformity
Copyright: The Tire Society
FIGURE 1
FIGURE 1

T1H of tires in the CW and CCW directions.

FIGURE 2
FIGURE 2

Coordinate system.

FIGURE 3
FIGURE 3

Schematic of the phases of the 1st harmonic runout and the induced T1H.

FIGURE 4
FIGURE 4

Schematic of the phases of the 1st harmonic mass variation and the induced T1H.

FIGURE 5
FIGURE 5

Simulated and tested R1H generated by a 0.75 mm 1st harmonic runout.

FIGURE 6
FIGURE 6

Simulated and tested T1H generated by a 0.75 mm 1st harmonic runout.

FIGURE 7
FIGURE 7

Simulated T1H generated by a 0.75 mm 1st harmonic runout in the CW and CCW directions.

FIGURE 8
FIGURE 8

Simulated T1H generated by a 1st harmonic mass variation of 0.293 kg/m in the CW and CCW directions.

FIGURE 9
FIGURE 9

Normalized waveform of the 1st harmonic runout and the generated T1H at 120 kph.

FIGURE 10
FIGURE 10

Normalized waveform of the 1st harmonic mass variation and the generated T1H at 120 kph.

FIGURE 11
FIGURE 11

T1H magnitude difference in the CW and CCW directions versus phase difference between runout and mass variation at 120 kph. (a) Tire 1. (b) Tire 2.

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