• Title/Summary/Keyword: ventilated disk brake

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A Study on Thermal Cracking of Ventilated Brake Disk of a Car Using FEM Analysis (FEM을 이용한 벤틸레이티드 브레이크 디스크의 열균열 현상에 관한 연구)

  • Kim Ho-Kyung;Chung Chin-Sung;Choi Myung-Il;Lee Young-In
    • Tribology and Lubricants
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    • v.21 no.2
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    • pp.63-70
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    • 2005
  • This study presents the thermal cracking on a commercial vehicle ventilated brake disk. Distributions of temperature and thermal stress of the disk were analysed, using FEM analysis, under the several driving conditions with actual vehicle specifications. The results from the fatigue tests on the disk material were compared with those from FEM analysis. In case of deceleration of 0.6 g with initial vehicle speed of 97, 140, and 160 km/h, the maximum compressive stress at the disk surface of disk due to braking was 224, 318, and 362 MPa, respectively. It was estimated that each damage fraction of 0.00005, 0.00050, 0.00136 per full stop was imposed on the brake disk in case of deceleration of 0.6 g with initial vehicle speed of 97, 140, and 160 km/h, respectively.

Thermal Stress Analysis for a Brake Disk considering Pressure Distribution at a Frictional Surface (마찰면의 압력 분포를 고려한 제동디스크의 열응력 해석)

  • Lee Y.M.;Park J.S.;Seok C.S.;Lee C.W.;Kim J.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.842-846
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    • 2005
  • A brake disk and a pad are important parts that affect the braking stability of a railway vehicle. Especially, because a brake disk stops the vehicle using conversion of the kinetic energy to frictional energy, thermal fatigue cracks are generated by the cyclic thermal load, as frictional heat, on a frictional surface and these cracks cause the fracture of a brake disk. Therefore, many researches for the thermal stress must be performed to improve the efficiency of brake disk and ensure the braking stability. In this study, we performed the thermal stress analysis for a ventilated brake disk with 3-D analysis model. For that, we simplified the shape of a ventilated hole to minimize problems that could be occurred in analysis process. Thermal stress analysis was performed in case that pressure distributions on a frictional surface is constant and is not. To determine pressure distributions of irregular case, pressure distribution analysis for a frictional surface was carried out. Finally using the results that were obtained through pressure distribution analysis, we carried out thermal stress analysis of each case and investigated the results of thermal stress analysis.

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A Study of Thermal Behavior in Ventilated Disk Brake

  • Kim, Jin-Taek
    • KSTLE International Journal
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    • v.7 no.2
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    • pp.56-60
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    • 2006
  • By the increasing amount of vehicles, the increase of car accident served as a major momentum for remind the importance of braking system. The adequate design of a passenger car braking system, which is directly related to the safety of a car, is very important since the safety is an essential design parameter of a car to keep men and car from the damage. The thermal behaviors of the ventilated disk has been investigated based on the air cooling effects during repeat braking operations. In this study, the temperature and velocity fields of 3-D unsteady simulated model are obtained using a software package "FLUENT". The numerical results show that there exits a temperature nonuniformity between the disk faces contacting with pads.

고속전철용 디스크 브레이크의 열탄성 마멸에 관한 수치적 연구

  • 황준태;김청균
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.11a
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    • pp.269-275
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    • 1999
  • This paper presents the results of thermoelastic wear phenomena in ventilated disk brakes for a high-speed train using finite element method. The computed results show that the sinusoidal distortions due to non-uniform distributions of temperature profiles may lead to thermoelastic wears at the rubbing surface. This may decrease the life of a disk brake and produce micro-cracks, noise and squeals between two rubbing surfaces.

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STUDY ON COOLING PERFORMANCE BY CONVECTIVE HEAT TRANSFER WITH DIFFERENT DISK BRAKE SHAPES (브레이크 디스크 형상에 따른 대류열전달에 의한 방열성능 연구)

  • Park, C.W.;Lee, D.R.
    • Journal of computational fluids engineering
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    • v.21 no.1
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    • pp.64-71
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    • 2016
  • This research is to numerically investigate the convective cooling performance in the Disk brake. Research concentrates on the heat transfer coefficient and cooling performance which are selected with cooling local locations. Cooling performance of the Hole disk has been compared by Ventilated Disk. According to the results of heat transfer on the disk brake, activated velocity distributions more appear in the Hole disk. This is due to the fact that a number of hole units have exactly 120 on the surface of the hole disk. Therefore, velocity distributions of hole disk brake is better activated than Ventilated disk. According to the calculations of Nusselt number between surface and atmosphere in the interested cooling area, average value of cooling effect has been increased 13.5% by the hole disk at driving of speed 65 km/h situation and grown 18% by the hole disk at driving speed of 100 km/h. Due to the flow of air through the hole route, cooling performance of the hole disk was very excellent. In addition, cooling effect on edge of the bottom is better than the vicinity of center.

A Study for the Cooling Performance of a Brake with Heat Pipes (히트 파이프를 장착한 디스크브레이크의 냉각 성능에 관한 연구)

  • Kim, Moo-Geun;Ko, Sung-Kyu;Lee, Moon-Wan
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.4
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    • pp.563-569
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    • 2008
  • During braking operation, the surfaces of disk have severe contact conditions and high frictional heat would be generated between disk and pad surfaces. The heat makes high temperature gradient on disk surfaces and results in thermal deformation. To enhance the frictional heat dissipation, heat pipes are embedded in the ventilated type disk along the radial direction. The temperatures of the inner vent type disk and the brake disk with heat pipes are compared at the same operating conditions. By comparison a brake disk with heat pipes has higher cooling performance than the inner vent type disk.

A Study on Thermal Deformation Volume of Motorcycle Brake Disk using Regression Analysis (회귀분석에 의한 모터싸이클 브레이크 디스크의 열변형량에 관한 연구)

  • Ryu, Mi-Ra;Byoun, Sang-Min;Park, Heung-Sik
    • Tribology and Lubricants
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    • v.25 no.2
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    • pp.102-107
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    • 2009
  • The thermal deformation volume of motorcycle break disk was studied using a disk-on-pad type friction tester. Thermal deformation volume of motorcycle break disk have an effect on the frictional factor such as applied load, sliding speed, sliding distance and number of ventilated disk hole. However, it is difficult to know the mutual relation of these factors on thermal deformation volume. In this study, the thermal deformation volume with ANSYS workbench are obtained by application of temperature from mechanical test. From this study, the result was shown that the motorcycle break disk with ventilated hole 3 have the most excellent thermal deformation characteristics. The regression equation with frictional factors which have a trust rate of 95% for prediction of thermal deformation volume of motorcycle break disk was composed.

Numerical Study on the Thermal Distortions of Ventilated Disk Brakes Due to Air Cooling Effects (벤틸레이티드 디스크 브레이크에서 공냉효과가 열변형 거동에 미치는 영향에 관한 수치적 연구)

  • 조승현;이일권;김청균
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.06a
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    • pp.332-338
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    • 1999
  • A coupled thermal-mechanical analysis has been presented for the thermal distortions of the ventilated disk brakes during IS braking operations. The FEM results show that the bendings and distortions of the disk toward the left side are decreased, but the sinusoidal distortion of the disk rubbing surface along the arc length of the vent hole is highly increased by increasing the convective air cooling effects, which is heavily related to the squeal, wear and micro-thermal crackings at the rubbing surfaces due to uneven dissipation rates of friction heatings.

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Wear Loss Presumption of Motorcycle Disk Brake Using Design of Experiment (실험계획법에 의한 이륜자동차 브레이크 디스크의 마멸량 예측)

  • Park, Gyu-Jung;Park, Heung-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.6 no.4
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    • pp.15-21
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    • 2007
  • The effect of manufacturing parameters on friction characteristics of motorcycle break system was studied using a disk-on-pad type friction tester. Such parameters conditions have an effect on the frictional factor such as number of ventilated disk hole, applied load, sliding speed, and sliding distance. However, it is difficult to know the mutual relation of these factors. In this study, the friction characteristics using design of experiment containing 4 elements were investigated for an optimal condition for the best motorcycle break system employing regression analysis method. From this study, the result was shown that the applied load in frictional factors was the most important, next to sliding speed, number of ventilated disk hole.

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Finite Element Analysis on the Dynamic Behaviors of a Disk-Pad Brake in High-Speed Trains (고속전철용 디스크-패드 브레이크의 동적거동 특성에 관한 유한요소해석)

  • 김청균;조승현
    • Tribology and Lubricants
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    • v.16 no.2
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    • pp.7-7
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    • 2000
  • Using a coupled thermal-mechanical analysis, the dynamic distortion of the ventilated disk brakes has been presented for a high-speed train. The offset ratio between the maximum and minimum values of the thermal distortions has been analyzed as a function of a braking number. The computed FEM results show that the offset rations in radial direction are much greater than those of circumferentially distorted components. This means that the axial distortions in radial direction may dominantly produce thermally caused wears and cracks at the rubbing surfaces.