• Elastomers and Composites
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• v.34 no.4
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• pp.350-359
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• 1999

Conversion and oil-yield of a used automotive tire sample in supercritical decomposition and extraction for three solvents such as water, 28% ammoina solution and ammonia, were compared. Supercritical extraction with ammonia gave the highest conversion and oil-yield at the same temperature and pressure. In this paper, supercritical ammonia was used as major solvent and tetralin acting as hydrogen-donor, was used as cosolvent. As the amount of tetralin increased, oil-yield was Increased. When a tire sample was extracted by supercritical ammonia, oil-yield was 48.8% at $280^{\circ}C$, 22.3MPa. But when the weight ratio of tetralin to tire sample (weight of tetralin/weight of tire sample) was 5, oil-yield was 61.2% at $280^{\circ}C$ and 22.3 MPa. These phenomena indicate that as radicals produced in supercritical decomposition become stable, the polymerization and the second decomposition of products may be inhibited. Supercritical extraction of a tire sample swollen by tetralin gave high oil-yield although the amount of tetralin was a little.

• Journal of the korean Society of Automotive Engineers
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• v.25 no.3
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• pp.14-19
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• 2003

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.803-812
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• 2006

In order to reduce the negative effects of dynamic coupling among vehicle subsystems and improve the handling performance of vehicle under severe driving conditions, a vehicle chassis control integration approach based on a main-loop and servo-loop structure is proposed. In the main-loop, in order to achieve satisfactory longitudinal, lateral and yaw response, a sliding mode controller is used to calculate the desired longitudinal, lateral forces and yaw moment of the vehicle; and in the servo-loop, a nonlinear optimizing method is adopted to compute the optimal control inputs, i.e. wheel control torques and active steering angles, and thus distributes the forces and moment to four tire/road contact patches. Simulation results indicate that significant improvement in vehicle handling and stability can be expected from the proposed chassis control integration.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.7
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• pp.595-601
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• 2015

This paper presents an unified chassis control with electronic stability control (ESC) and active front steering (AFS) under lateral force constraint on AFS. When generating the control yaw moment, an optimization problem is formulated in order to determine the tire forces, generated by ESC and AFS. With Karush-Kuhn-Tucker optimality condition, the optimum tire forces can be algebraically calculated. On low friction road, the lateral force in front wheels is easily saturation. When saturated, AFS cannot generate the required control yaw moment. To cope with this problem, new constraint on the lateral tire force is added into the original optimization problem. To check the effectiveness of the propose method, simulation is performed on the vehicle simulation package, CarSim.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.234-243
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• 2002

When a vehicle is operated over sort terrain, torque(or soil thrust) applied to driving wheel brings about shear displacement far soil due to compression and shear failure of soil under tire. This shear displacement give rise to slip and a additional sinkage due to slip. This additional sinkage is usually referred to as slip-sinkage. The slip-sinkage is affected by soil conditions and inflation pressure of tire. This slip-sinkage influence tractive performance on driving wheel . We conducted the experimental study far investigating the effect of slip on sinkage and tractive performance of driving wheel, such as motion resistance, thrust and drawbar pull. The experiment was carried out over three different soil conditions(soft, hard and very hard soil) far a tire with three levels of inflation pressure(120kPa, 240kPa and 360kPa). The results of this study show qualitatively slipsinkage characteristics and slip-tractive performance relationships of driving wheel with soil conditions and inflation pressure of tire.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.102-110
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• 2008

It is well known that the acoustic cavity inside the tire-wheel assembly contributes to vehicle interior noise and ride comfort. In this paper, we performed acoustic and structural modal testings by varying the temperature ranging from $20^{\circ}\;to\;45^{\circ}C$ to investigate the effects of temperature on acoustic cavity resonance and structural vibration characteristics for unloaded and loaded tires. The testing has given us some findings, which are reported in this paper.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.128-133
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• 2008

In this paper, a new technique was suggested to estimate vehicle speed for the traffic accident reconstruction, and accident investigators can estimate initial vehicle speed based on this suggested technique. Turning tests with several vehicle speeds were executed and compared with the motion of the vehicle and the shape of the tire marks. A new method for estimating the coefficient of friction is suggested by using the longitudinal and lateral components of tire marks. And also, a speed calculation graph is suggested to estimate vehicle speed for traffic accident reconstruction.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.151-162
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• 1998

During a straight driving and cornering maneuver by a vehicle various forces and moments are exerted on the tire's footprint. A cornering properties, handling and stability performances of vehicle can be predicted by these forces and moments values. Therefore, on this study, a lateral force and a aligning torque are predicted by these forces and moments values. Therefore, on this study, a lateral force and a aligning torque are predicted using a finite element method. Contact area of the tire between bead and wheel are fixed to simplify of a finite element model. Lateral force is exerted on the rigid surface as a real load with Coulum friction after inflate and load vertically. Then, rotate the tire's axle to simulate a free rolling untill taken the equilibrium of a aligning torque. Also, experimental observations are made to test a reliability of a FE analysis conducted in this study. The finite element analysis said that good agreement was obtained with experimental results of these cornering properties, giving confidence within about one percent. So it os recommended that a finite element analysis can be used as a good tool to predicted the tire cornering properties.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.93-99
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• 2002

Ride comfort, one of the most important performances of a car, is affected by vibration, noise, dynamic movement, and ergonomic factors. Among these factors, ride comfort vibration is heavily affected by the seat system, tire, suspension, and body structure. In this study, vibration characteristics of seat, tire, suspension, and body structure are analyzed. The vibration transfer function from the road input to the human body is also investigated.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.24-32
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• 2012

A large fraction of urban $PM_{10}$ concentrations is due to non-exhaust traffic emissions including road dust, tire wear particles, and brake lining particles. Although potential health and environmental impacts associated with tire wear debris have been increased, few environmentally and biologically relevant studies of actual tire wear debris have been conducted. Tire wear particles (TWP) are released from the tire tread as a result of the interaction between the tire and the pavement. Roadway particles (RP), meanwhile, are particles on roads composed of a mixture of elements from tires, pavements, fuels, brakes, and environmental dust. The main objective of present study is to identify the contribution of tires to the generation of RP and to assess the potential environmental and health impacts of this contribution. First, a mobile measurement system was constructed and used to measure the roadway particles on asphalt road according to vehicle speed. The equipment of the mobile system provides $PM_{10}$ concentrations by Dusttrak DRX and number density & size distribution measurements of fine and ultra-fine particles by a fast mobility particle sizer (FMPS) and an aerosol particle sizer (APS). When traveling on an asphalt road at constant speed, there is a clear tendency for PM10 concentration to increase slightly in accordance with an increase in the vehicle speed. It was also found that considerable brake wear particles and particles from tire/road interface were generated by rapid deceleration of the vehicle. The morphology and elements of the roadway particles were also analyzed using SEM-EDX technique.