• Journal of Biosystems Engineering
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• v.26 no.3
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• pp.245-252
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• 2001

This study was carried out to investigate the effect of three factors(dynamic load, inflation pressure and multiple passes of the tire) on the contact pressure and the soil stresses under the tire. A series of soil bin experiment was conducted with a 6.00R14 radial-ply tire for sandy loam soil. Tire contact pressure at soil surface and soil stresses at 10cm and 20cm soil depth were measured for the three levels of dynamic load(1.17kN, 2.35kN and 3.53kN), for the three levels of tire inflation pressure(103.42kPa, 206.84kPa and 413.69kPa), and for five different number of passes(1, 2, 3, 4 and 5 pass). The following results were drawn from this study 1) As dynamic load, inflation pressure and number of passes of the tire increased, tire contact pressure at soil surface and soil stresses at 10cm and 20cm soil depth increased accordingly. Thus increased in dynamic load, inflation pressure and number of passes of the tire would increase soil compaction. 2) The effect of three different factors, or dynamic load, inflation pressure and number of passes of the tire, decreased as the soil depth increase. Consequently, it was found that the soil compaction at a shallow depth in soil is larger than that at deep place in soil. 3) The increase of dynamic load and number of passes increased soil stress exponentially, but the increase of inflation pressure increased soil stress linearly. The effect of tire inflation pressure on soil stress was relatively less than that of the dynamic load. Therefore, it was concluded that dynamic load is more important factor affecting soil compaction in comparison to the inflation pressure of tire.

• Journal of Biosystems Engineering
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• v.27 no.1
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• pp.1-10
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• 2002

This study was carried out to investigate experimentally the effect of three factors(dynamic load, inflation pressure and number of passes of tire) on soil compaction under the tire. The experiment were conducted with a 6.00R14 radial-ply tire for sandy loam soil using soil bin system. To evaluate the effect of three factors on soil compaction under the tire, the sinkage. density and volume of soil under the tire were measured fur the three levels of dynamic load(1.17kN, 2.35kN and 3.53kN), for the three levels of tire inflation pressure(103.42kPa, 206.84kPa and 413.67kPa), and for three different number of passes(1, 3 and 5). The results of this study can be summarized as follows : 1. As dynamic load, inflation pressure and number of passes of the tire increased, soil sinkage and density increased. and volume of soil decreased. Thus increase in dynamic load, inflation pressure and number of passes of the tire would increase soil compaction. 2. The effect of tire inflation pressure on sinkage. density and volume of soil under the tire was relatively less than that of the dynamic load. Therefore, it was concluded that dynamic load was more important factor affecting soil compaction in comparison to the inflation pressure of tire. 3. The effect of three different factors on sinkage, density and volume of soil decreased as the soil depth increase. Consequently, it was fecund that soil compaction at a shallow depth in soil was larger than that at deep place in soil.

• Smart Structures and Systems
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• v.19 no.2
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• pp.151-161
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• 2017

A new method is developed to estimate road profile in order to estimate IRI based on the ASTM standard. This method utilizes an accelerometer and a Dynamic Tire Pressure Sensor (DTPS) to estimate road roughness. The accelerometer measures the vertical axle acceleration. The DTPS, which is mounted on the tire's valve stem, measures dynamic pressure inside the tire while driving. Calibrated transfer functions are used to estimate road profile using the signals from the two sensors. A field test was conducted on roads with different quality conditions in the city of Brockton, MA. The IRI values estimated with this new method match the actual road conditions measured with Pavement Condition Index (PCI) based on the ASTM standard, images taken from an onboard camera and passengers' perceptions. IRI has negative correlation with PCI in general since they have overlapping features. Compared to the current method of IRI measurement, the advantage of this method is that a) the cost is reduced; b) more space is saved; c) more time is saved; and d) mounting the two sensors are universally compatible to most cars and vans. Therefore, this method has the potential to provide continuous and global monitoring the health of roadways.

• 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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.87-97
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• 2020

In general, tires require various sensors and power supply devices, such as batteries, to obtain information such as pressure, temperature, acceleration, and the friction coefficient between the tire and the road in real time. However, these sensors have a size limitation because they are mounted on a tire, and their batteries have limited usability due to short replacement cycles, leading to additional replacement costs. Therefore, vibration energy harvesting technology, which converts the dynamic strain energy generated from the tire into electrical energy and then stores the energy in a power supply, is advantageous. In this study, the output voltage and power generated from piezoelectric elements are predicted through finite element analysis under static state and transient state conditions, taking into account the dynamic characteristics of tires. First, the tire and piezoelectric elements are created as a finite element model and then the natural frequency and mode shapes are identified through modal analysis. Next, in the static state, with the piezoelectric element attached to the inside of the tire, the voltage distribution at the contact surface between the tire and the road is examined. Lastly, in the transient state, with the tire rotating at the speeds of 30 km/h and 50 km/h, the output voltage and power characteristics of the piezoelectric elements attached to four locations inside the tire are evaluated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.3
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• pp.249-256
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• 2010

This paper presents performance analysis of a quarter-vehicle magneto-rheological(MR) suspension system with respect to different tire pressure. As a first step, MR damper is designed and manufactured based on the optimized damping force levels and mechanical dimensions required for a commercial mid-sized passenger vehicle. After experimentally evaluating dynamic characteristics of the manufactured MR damper, the quarter-vehicle MR suspension system consisting of sprung mass, spring, tire and the MR damper is constructed in order to investigate the ride comfort. After deriving the equations of the motion for the proposed quarter-vehicle MR suspension system, vertical tire stiffness with respect to different tire pressure is experimentally identified. The skyhook controller is then implemented for the realization of quarter-vehicle MR suspension system. Ride comfort characteristics such as vertical acceleration RMS and weighted RMS of sprung mass are evaluated under various road conditions.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.409-414
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• 2001

This paper reports a technique for measuring a three-dimensional soil deformation and a simplified method to determine the three-dimensional contact area of agricultural tires in a soil bin. A Pirelli 12.4R28 radial-ply tire was used on soft soil. Effects of dynamic load and inflation pressure were determined using the equipment for measuring soil deformation on the soil surface. Soil deformation measurements were made under three conditions of over-load (59kPa-14.2kN), rated-load (108kPa-11.8kN) and under-load (157kPa-9.3kN) in the combinations of the inflation pressures (kPa) and the tire load (kN). The results from three conditions were shown that the contact area of the over-load increased considerably bigger than those of the rated-load and the under-load. Therefore, to regulate soil deformation, the inflation pressure and the tire load should be set according to the soil conditions.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.1
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• pp.64-72
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• 2009

In order to convert efficiently vibration energy of a car tire wheel into electrical power by using piezoelectric materials, the design of the materials must be performed for the dynamic characteristics of the piezoelectric materials to be matched with them of the vibration energy sources well. An accelerometer was installed on the tire wheel with a slip ring to investigate the dynamic mode of the wheel as one of the vibration energy sources. During road test, the measurement on the vibration mode of the tire wheel was performed with variations of car speed and road condition. The experimental data were analyzed details for availability as a micro power source for wireless TPMS(Tire Pressure Monitoring System).

• Elastomers and Composites
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• v.34 no.4
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• pp.321-331
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• 1999

The curing process is the final step in tire manufacturing whereby a green tire built from layers of rubber compounds is formed to the desired shape and the compounds are converted to a strong, elastic materials to meet tire performance needs under elevated pressure and temperature in a press. A numerical optimization procedure was developed to improve product quality in a tire curing process. First, a dynamic constrained optimization problem was formulated to determine the optimal condition of the supplied cure media during a curing process. The objective function is subject to an equality constraint representing the process model that describes the heat transfer and cures kinetic phenomena in a cure press and is subject to inequality constraints representing temperature limits imposed on cure media. Then, the optimization problem was solved to determine optimal condition of the supplied cure media for a tire using the complex algorithm along with a finite element model solver.

• 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.