• Journal of Biosystems Engineering
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• v.12 no.4
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• pp.9-15
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• 1987

The vibrational characteristics of a radial-ply (155SR13 4PR) and a biased-ply tire (6.15-134PR) were investigated for examining the effects of tires with different structure on the ride characteristics of the vehicle. The natural frequencies at the tread band, mode shapes, and damping factors of two tires at the state of plane vibration were determined experimentally. The test work was performed at four levels of the inflation pressure, ranging from 171.7 kPa to 245.2 kPa, and three levels of the vertical load, deviating by 10% from the standard load designated by the Department of Transportation of the United States of America. The following results were drawn by the analysis of the test results: 1. The first-order natural frequencies of the radial-ply and the biased-ply tires at the tread band were 112 Hz and 159 Hz, respectively, at the state o f the free vibration when the inflation pressure of 196.2 kPa was applied. It was known that the biased-ply tire has higher resonant frequency than the radial-ply tire and the natural frequencies of the both tires move to the high frequency range as t he inflation pressure is increased. 2. The vibration modes of both tires were quite different. No big difference in mode shapes was examined as the inflation pressure was increased. But the natural frequencies of two tires were changed. For the radial-ply tire, no difference in mode shape was found whether the vertical load was applied or not. But a significant difference in mode shape was examined for the biased-ply tire. 3. Any difference was not found in damping factor as the different inflation pressures were applied. 4. When no vertical load was applied, damping factors of the radial-ply and biased-ply tire at the state of the natural vibration ranged from 2.6 to 5.9%, and from 4.1 to 7.8%, respectively. It was estimated that the radial-ply tire would have better cushioning than the biased-ply tire since the vertical spring rate of the radial-ply tire was much less than that of the biased-ply tire, even though the damping effect of the radial-ply tire was smaller than that of the biased-ply tire.

• The tire
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• s.88
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• pp.38-44
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• 1980

Bias Ply 타이어의 타이어 품질등급제 (UTQGS: Uniform Tire Quality Grading Standard)가 작년 4월 1일부로 발효되었다. 한편 Belted Bias 타이어의 UTQGS도 79년 10월1일 부터 발효되었으며, Radial타이어의 UTQGS는 80년 4월에 발효되었다.

• The tire
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• s.11
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• pp.17-18
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• 1968

• The tire
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• s.11
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• pp.6-13
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• 1968

• The tire
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• s.12
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• pp.4-8
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• 1968

• The tire
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• s.2
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• pp.14-15
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• 1967

• The tire
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• s.1
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• pp.46-46
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• 1967

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.47-55
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• 2008

In this paper, comparisons are presented on the predicted tensile strains which can affect the fatigue life of a thin asphalt concrete (AC) pavement near the surface of pavement from three-dimensional (3D) finite element (FE) using 3D measured tire contact stresses of a radial tire and a bias ply tire and a layered linear elastic program (BISAR). The objective was to analyze the stress distributions for a 11R22.5 radial tire and a $10{\times}20$ bias ply tire, and to compare the predicted tensile strains at the top and bottom of AC surface using different analysis methods. The results show that the stress distributions of two tires are similar but the 11R22.5 radial tire has much higher vertical contact stress than that of the $10{\times}20$ bias ply tire. The predicted tensile strains at the bottom of AC layer under the center of tire showed higher value by BM (BISAR with the measured contact area) method, which the measured tire contact area is used in a layered elastic program, while the tensile strain at the top of AC surface of 3.5cm offset distance from tire edge by 3D FE analysis showed the highest values among three analysis methods.

• Journal of Biosystems Engineering
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• v.29 no.4
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• pp.301-306
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• 2004

Soil stresses were measured beneath the centerline of one new 12.4R28 radial-ply tractor tire. The tire was operated with three inflation pressures(59㎪ 108㎪ and 157㎪) and a dynamic load of 14.2 kN and 20% slip. Soil stress state transducer(SST) measured the stresses in a hardpan soil profile. The depth of the SST was 250mm from soil surface. Analysis of the original soil stress data showed that the inflation pressure of tire did significantly affect the vertical stress. The major principal stresses calculated were more when the inflation pressure was 108㎪ than when it was 157㎪. The peak stresses of the major principal stresses presented more than those of the vertical stresses.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.123-130
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• 2001

The research described in this paper was aimed toward improving the understanding of the interaction of tire inflation pressure and the soil-tire interface stresses. A three-directional stress transducer was developed to measure stress distribution on undertread for a tractor tire. The transducer can directly measure three-directional stresses (normal stress, tangental stress and lateral stress and lateral stress) simultaneously and has both strong structure and high sensitivity, which is not changed by the abrasion of the detecting plate. Measurements of soil-undertread interface stresses were made at tire center on undertread on a 12.4-R24 radial tractor tire opeated at three combinations of a dynamic load (11.8kN) and three inflation pressures (59kPa, 108kPa and 157kPa). These measurements showed that as inflation pressure increased, the soil-undertread interface stresses increased. The results of three stresses comparisons were shown that the peak normal stresses were considerably higher than the tangential peak stresses and the peak lateral stresses.