• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.4
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• pp.169-176
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• 2000

Longitudinal and lateral forces acting on tires are known to be closely related to the tract-ability braking characteristics handling stability and maneuverability of ground vehicles. In thie paper in order to develop tire force monitoring systems a monitoring model is proposed utilizing not only the vehicle dynamics but also the roll motion. Based on the monitoring model three monitoring systems are developed to estimate the tire force acting on each tire. Two monitoring systems are designed utilizing the conventional estimation techniques such as SMO(Sliding Mode Observer) and EKF(Extended Kalman Filter). An additional monitoring system is designed based on a new SKFMEC(Scaled Kalman Filter with Model Error Compensator) technique which is developed to improve the performance of EKF method. Tire force estimation performance of the three monitoring systems is compared in the Matlab simulations where true tire force data is generated from a 14 DOF vehicle model with the combined-slip Magic Formula tire model. The built in our Lab. simulation results show that the SKFMEC method gives the best performance when the driving and road conditions are perturbed.

• Journal of Ocean Engineering and Technology
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• v.23 no.3
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• pp.20-29
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• 2009

This study investigated the shear strength characteristics of waste tire powder-added lightweight soil (WTLS), which were developed to recycle dredged soil, bottom ash, and waste tires. The WTLS used in this experiment consisted of dredged soil, bottom ash, waste tire powder, and cement. Test specimens were prepared with various contents of waste tire powder ranging from 0% to 100% at 25% intervals and bottom ash contents of 0% or 100% by the weight of the dry dredged soil. In this study several series of direct shear tests were carried out, which indicated that the shear properties of WTLS were strongly influenced by the mixing conditions, such as the waste tire powder content and bottom ash content. The unit weight, as well as the shear strength of the WTLS, decreased with an increase in waste tire powder content. The shear strength of WTLS with bottom ash was 1.34 times greater than that of WTLS without bottom ash. An average increase in cohesion of 30 kPa was obtained in WTLS with the inclusion of bottom ash due to the bond strength induced from the pozzolanic reaction of the bottom ash. In this test, the maximum value of the internal friction angle was obtained with a 25% content of waste tire powder.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.3
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• pp.378-384
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• 1997

In curing process of tire, contact and slip occurs between green tire and curing bladder. The curing process is a critical step in the manufacture of tires. In this investigation, curing bladder shaping is examined using a finite element method. Specifically, a finite element model between the inner part of green tire and the outer part of curing bladder is generated using contact element and curing bladder is generated using incompressible element. Numerical analysis are performed on two different bladder types, different overall outer diameters of curing bladder and different heights of curing bladder. Numerical results show that contact pressure is increased by using toroidal type of curing bladder, increasing overall diameter and increasing height of curing bladder. To obtain natural equilibrium carcass line, there is a requirement in increasing contact pressure of the section between side and bead.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.197-204
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• 2003

This paper develops a computer model for estimating the handling of a cabover type large-sized truck. The truck is composed of front and rear suspension systems, a frame, a cab, and ten tires. The computer model is developed using ADAMS. A shock absorber, a rubber bush, and a leaf spring aunt a lot on the dynamic characteristic of the vehicle. Their stiffness and damping coefficient are measured and used as input data of the computer model. Leaf springs in the front and rear suspension systems are modeled by dividing them three links and joining them with joints. To improve the reliability of the developed computer model, the frame is considered as a flexible body. Thus, the frame is modeled by finite elements using MSC/PATRAN. A mode analysis is performed with the frame model using MSC/NASTRAN in order to link the frame model to the computer model. To verify the reliability of the developed computer model, a double lane change test is performed with an actual vehicle. In the double lane change, lateral acceleration, yaw rate, and roll angle are measured. Those test results are compared with the simulation results.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.483-486
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• 2008

본 연구에서는 디스크 이동식 열분해 실증 설비를 이용하여 폐타이어 열분해 반응을 수행하였고, 생성된 열분해 생성물들의 특성을 분석하였다. 폐타이어 열분해 반응은 약 $550^{\circ}C$에서 90분간 진행되었고, 반응 결과 Recovered Oil, Carbon Black, Non Condensing Gas(NC Gas)가 생성되었다. 폐타이어 열분해 생성물의 수율은 Recovered Oil $40{\sim}50%$, Carbon Black 30$\sim$35%, NC Gas 10$\sim$15%, Steel 10$\sim$15%로 나타났다. 폐타이어 열분해 반응 후 생성된 Recovered Oil은 비점 및 특성 분석 결과 상업용 중유와 비슷한 성질을 나타냈고, 폐타이어 열분해 반응의 또 다른 생성물인 Carbon Black은 특성 분석 결과 고정 탄소 비율이 낮은 반면 회분과 휘발분의 비율이 높아 상업용으로 사용하기 위해서는 적절한 정제 과정이 필요함을 알 수 있었다.열분해 과정 중에 생성된NC Gas는 GC/MS를 이용하여 성분 분석을 수행한 결과, $CO_2$, $CH_4$를 비롯하여 주로 탄화수소류로 이루어졌으며, 대부분이 연료 가스로 구성되어 있어 열분해 반응의 열원으로서 사용이 가능하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.409-412
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• 2005

Just as the vibration modes of a beam are dependent on its end constraints or boundary conditions. Vibration modes of a tire are dependent on its patch and spindle constraints. This dependence is key to understanding the dynamic properties of a tire and is apparent in various analytical and experimental investigations in the literature. One of the main task in a modal analysis is the measurement of the Frequency Response Function (FRFs). Because all the subsequent analysis is based on these FRFs, their quality is critically important in obtaining accurate modal parameter estimates. In rotating systems, FRFs are frequently contaminated by harmonic peaks related to such factors as imbalance, misalignment. This harmonic peaks appear in the FRFs as sharp spikes, which can be erroneously treated in modal curve-fitting procedures as structural modes. The harmonic peaks removal method is demonstrated by application to modal analysis on rotating tires. The results show substantial improvement in FRF quality.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.415-420
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• 2007

The objective of this study analyzes the influence of shimmy & shake phenomena due to tire design parameters which are RFV(radial force variation), DB(dynamic balance), RRO(radial run out) and air pressure. These parameters are inspection items for Q.C. after tires are manufactured. In order to analyze these parameters on this study, vehicle driving tests were achieved. The test modes are two type which are constant speed and coast-down driving. On this tests the dynamic characteristics of shimmy & shake are measured by the 3-axises accelerometers at the various positions that are knuckle(left & right), rack pinion, seat and steering wheel. In according to analyzed results, the longitudinal vibration of knuckle parts affects the lateral vibration of rack pinion and this vibration affects the lateral vibration of steering wheel that is the shimmy phenomena. Also the over and under DB by comparison with normal DB and the increment of RRO affect the occurrence of shimmy & shake phenomena.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.8
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• pp.720-728
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• 2012

It is important for identification of noise and vibration problem of tire to consider influence of interaction between road and tire. A quantification of road noise is a challenging issue in vehicle NVH due to extremely complicated transfer paths of road noise as well as the difficulty in an experimental identification of input force from tire-road interaction. A noise caused by tire is divided into road noise(structure-borne noise) and pattern noise(air-borne noise). Pattern noise is caused by pattern shape of tire, which has larger than 500 Hz, but road noise is generated by the interactions between a tire and a vehicle body. In this paper, we define the quantitative analysis for road noise caused by interactions between tire and road parameters. For the identification of road noise, the chassis dynamometer that is equipped $10mm{\times}10mm $ square cleat in the semi-anechoic chamber is used, and the tire spindle forces are measured by load cell. The vibro-acoustic transfer function between ear position and wheel center was measured by the vibro-acoustic reciprocity method. In this study three tires with different type of mechanical are used for the experiment work.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.4
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• pp.315-323
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• 2013

Tire noise is divided into a road noise(structure-borne noise) and a pattern noise(air-borne noise). Whilst the road noise is caused by the structural vibration of the components on the transfer path from tire to car body, the pattern noise is generated by the air-pumping between tire and road. In this paper, a practical method to estimate the pattern noise inside a passenger car is proposed. The method is developed based on the sound intensity and airborne source quantification. Sound intensity is used for identifying the noise sources of tire. Airborne source quantification is used for estimating the sound pressure level generated by each noise source of a tire. In order to apply the airborne source quantification to the estimation of the sound pressure, the volume velocity of each source should be obtained. It is obtained by using metrics inverse method. The proposed method is successfully applied to the evaluation of the interior noises generated by four types of tires with different pattern each other.

• The Journal of the Acoustical Society of Korea
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• v.30 no.1
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• pp.49-55
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• 2011

The effects of monaural beating sound generated according to the number of tire pitch blocks to human body are measured from experiments, and the possibilities of similar positive effects of enhancing alpha waves in human brain are investigated. Due to the requirement of repeatability and measurement conditions, recorded sounds of the tire noise are used for the experiment in a quiet room and human responses are measured using HRV. Although the number of statistically meaningful results was small, it showed that positive human reactions are probably possible.