• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.207-212
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• 2001

In this paper, dynamic stability and vibration characteristics of a flexible shoe in drum brake systems are investigated. The frictional force between the drum and the shoe is assumed as a distributed frictional force, while the shoe is modeled as an elastic beam supported by two translational springs at both ends and elastic foundations. Governing equations of motion are derived by energy expressions, and numerical results are calculated by finite element method. Through the numerical simulation, critical distributed frictional forces are calculated by changing the stiffness of two translational springs and elastic foundation parameters. It is also shown that the beam loses its stability by flutter and divergence depending on the stiffness of elastic supports and elastic foundation parameters. Finally, the time responses of the beam corresponding to their instability types are demonstrated.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.60-66
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• 2011

In this paper, the computer simulation analyzed the effective plastic strain and temperature behaviors. The quantitative analyses which proposed the effective mold design of S/CAM shaft was executed. The parameters of forging shape that affected on the optimize conditions that was calculated with simple equation were investigated. it is expected that the developed analysis model and design technique would greatly contribute to the drum brake optimal design considering effective plastic strain and temperature affected behaviors. This development could save more than 20% of production cost and reduced failure rate to more than 30%. By improving the life span of mold from 15,000 to 25,000, financial difficulty of company imposed on a mold manufacture could be overcome.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.4
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• pp.56-65
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• 1986

This paper theoretically analyzed the relations between the out-put braking torque and the wheel cylinder pressure in the leading-trailing drum brake for heavy duty truck as the characteristics of friction in break lining, comparing with the results derived from full-scale inertial brake dynamometer test in actual braking condition to develop reliable brake system in extensive using conditions. The main results obtained are as follows; 1) The characteristic curve representing the relations between BEF (Brake Effectiveness Factor) and Friction coefficient derived from theoretical analysis are consistent with the experimental results of dynamometer test. 2) According to the results of dynamometer test, the friction coefficient of brake lining is subject to initial brake speed and the actual using temperature in brake system.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.3
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• pp.10-18
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• 1993

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.173-180
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• 2001

In the case of axisymmetric thermal analysis of drum brakes, the distribution of frictional heat produced on the interface and temperature difference between mating frictional faces are very interesting problems to computational researchers. In the first part, the influence of the s-cam load angles and elastic modulus of the pad on the contact pressure distribution between pad and drum was checked by a three dimensional model. In the second part heat conduction from the interface to the pad and the drum was modeled by using a thin interface element, so artificial division of the generated frictional heat between pad and drum is not necessary. Temperature difference between mating frictional faces is successfully modeled by using the interface element. The influence of some parameters on the thermal distribution is checked. The analysis was performed by ABAQUS/Standard code.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.831-836
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• 2001

In the case of axisymmetric thermal analysis of drum brakes, the distribution of frictional heat produced on the interface and temperature difference between mating frictional faces are very interesting problems to computational researchers. In this paper, heat conduction from the interface to the pad and the drum was modeled by using a thin interface element, so artificial division of the generated frictional heat between pad and drum is not necessary. Temperature difference between mating frictional faces is successfully modeled by using the interface element. The influence of some parameters on tile thermal stress was checked. The analysis was performed by ABAQUS/Standard code.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04a
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• pp.117-121
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• 1996

Friction and wear test for non-asbestos material against cast iron drum were carried out to investigate the friction and wear characteristics of brake system. Its friction coefficient and wear volume were measured and compared with those of asbestos friction material. The experiment. was perforated tinder room temperature and various sliding conditions. After each experiment, the sin-faces of friction materials were observed by SEM.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.6
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• pp.751-755
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• 2011

Electric Parking Brake(EPB) is the system operated by electric control actuator. It differs from the mechanical parking brake system which is operated by lever and pedal in need of human power. The EPB system is composed of DC motor, helical and differential epicyclic gear, screw, cables, and sensor. This paper describes about the EPB system mathematically and constructs a modeling of the EPB system using MATLAB/SIMULINK. Especially, SimMechanics library in SIMULINK is used to make each parts of system a module. By made modeling of the friction torque between bolt and nut. Cable tension can be maintained after the motor operating stops.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1397-1404
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• 2014

Grab cranes are used for multi-purpose when the sand and soil are deposited into harbor wharf or the undersea construction is performed. Among the components of crane grab, the wire drum and disc brake pad are key expendables and have disadvantages that lot of heat is generated and very expensive when replacing them. In this study, the thermal image analysis for the disc brake, which works with wire drum of the crane is suggested. The suggested system performs the pad thermal diagnosis through the thermal image using the characteristics that the disc and pad surface temperatures are distributed abnormally before the brake failure and the disc pad damage. Therefore, the damage by the failure can be prevented by discovering the abnormality of the machine parts before failure and the life cycle of the pad and the cost can be extended and saved by operating the crane performing constant checkup for the overload.

• Composites Research
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• v.15 no.1
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• pp.41-52
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• 2002

This paper presents the thermo-elastic analysis for searching the behavior of carbon/carbon brake system during the braking period and the 3-D stress analysis to find the shape of the brake disk which is safe to the failure. The mechanical properties of the carbon/carbon brake disk were measured for both in-plane and out of plane directions. The mechanical properties were used as the input of the thermo-elastic analysis and 3-dimensional stress analysis for the brake disk. The gap between rotor clip and clip retainer is an important parameter in the loading transfer mechanism of the rotor disk. The change of gap was considered both the mechanical deformation and thermal deformation. Because the rotor clip and clip retainers were not contacted, they were excluded from the analysis model. Rotor disk was modeled by using the cyclic symmetry condition. The contact problems between rotor clip and key drum as well as between rotor disk and rotor were considered. From the results of the 3-D stress analysis, the stress concentration at the key hole of the brake disk was confirmed. The stress distributions were studied thor the variation of the rotation angle of the contact surface and the radius of curvature at the key hole part.