• Journal of the Korean Data and Information Science Society
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• 제16권2호
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• pp.401-410
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• 2005

In this paper, we calculate the premium rate of reliability insurance policy for brake pads for automobiles using real failure data obtained from use-condition. We try process capability analysis for the manufacturing process of brake-system. We describe the performance factors which have an effect on failure characteristics of brake pads. We also obtain the maximum likelihood estimates of shape and scale parameters of the fitted Weibull distribution for brake pads.

• Tribology and Lubricants
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• 제38권2호
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• pp.63-69
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• 2022

In this research, the rotordynamic characteristics of the labyrinth seal with and without swirl brake were predicted using the computational fluid dynamic (CFD) model. Based on previous studies, a simple swirl brake consisting of square vanes without stagger angle is designed and placed in front of the seal inlet. The rotating frame of reference is utilized to consider the whirling motion of the rotor in the steady-state analysis since the whirling motion is transient behavior in nature. CFD analysis was performed in the range of -1 to 1 pre-swirl ratio for a given seal and swirl brake design and operating conditions. The CFD analysis result shows that the swirl brake effectively reduces the pre-swirl since the circumferential fluid velocity of labyrinth seal with swirl brake was lower than that without swirl brake. The cross-coupled stiffness coefficient, which is greatly affected by the circumferential fluid velocity, increased with an increasing pre-swirl ratio in a seal without a swirl brake but showed a low value in a seal with a swirl brake. The change in the damping coefficient was relatively small. The effective damping coefficient of the labyrinth seal with swirl brake was generally constant and showed a higher value than the labyrinth seal without swirl brake.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.798-803
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• 2007

The brake system of railway plays an important role to enhance the speed of train, and the brake disc is one of major components relating to frictional braking. The performance enhancement of brake disc directly affects the braking performance of train. It is required to understand and investigate the factors need to be considered for the development of new brake disc with improved materials and performance. In this study, through the literature reviews of previous study, several factors including thermal crack phenomena, friction coefficient, materials and durability of disc, temperature characteristics, etc., were introduced for the design of improved brake disc. Moreover, based on the review results, the design direction of new brake disc was suggested. Eventually, a new brake disc with improved performance would be developed based on this investigation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.525-532
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• 2001

Experimental study has been conducted to clarify the pneumatic characteristics of brake system for freight train and enhance the performance of diaphragm valve. Empty-load and diaphragm brake systems are mainly used in the freight trains of KNR (Korean National Railroad). The train set is composed of thirty freight cars and diesel locomotive. From the experimental results, new quick release valve shortens release time after brake application. In case of normal brake application, the release time is short by 34% of that of original diaphragm control valve. It will be expected to assure brake-release application and reduce maintenance efforts.

• 한국자동차공학회논문집
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• 제9권3호
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• pp.108-120
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• 2001

In this paper, the braking performance considering the dynamic weight is analyzed about the tractor-semitrailer vehicle. The basic brake performance, the parking brake performance, the emergency brake performance and the locking point deceleration etc. are to be calculated for the brake system design of the tractor-semitrailer vehicle. This braking performance is related to traffic regulations and braking characteristics according to the vehicle deceleration, the tire-road friction coefficient and specifications of the air brake system. The design program for the braking performance based on various design variables of the vehicle and the air brake system is developed integrating the analysis functions. This design program is developed by an object oriented programming method that is windows based. GUI (Graphic User Interface) function and the convenience of operating are greatly considered.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권12호
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• pp.659-663
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• 2002

The brake systems of high-speed train are to be equipped with three different brake systems, such as regenerative brake with regenerative feedback in driving car, a pneumatic disc brake, and non-contact linear eddy-current brake(ECB). The regenerative brake and the pneumatic disc brake are acting on the wheels. Their achievable braking force depends on the adhesive coefficient, which is influenced by the weather condition and speed, between the wheel and The linear eddy current brake gets an economical solution in the high-speed train because of the independence of the adhesive coefficient, no maintenance needed. and the good control characteristics. The braking force and the normal force of ECB for korean high-speed train are analysed by the 2D FEM(Finite Element Method). Finally the normal force is compared with the experiential values to verify the analysis.

• 오토저널
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• 제15권2호
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• pp.64-75
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• 1993

In this study, the function of a hydraulic brake system with a vacuum booster is systematically analyzed according to the mutual relations which follow : - the brake pedal force vs. booster cylinder input force - the booster output force vs. master cylinder input force - the hydraulic line pressure vs. braking deceleration. A computer program is developed based on the theory which is able to predict and analyze the pedal force characteristics at the beginning of the initial stage of brake system design. Analytical results show good agreement with the experimental vehicle test.

• 항공우주시스템공학회지
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• 제3권2호
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• pp.39-43
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• 2009

Eddy currents are generated when a moving conductor is exposed to a stationary magnetic field, or vice-versa. These currents create their own magnetic field, causing a repulsive force between the magnetic material and the conductor. Using this concept, a magnetic brake system can be established by the permanent magnets and a conductive material. In this paper, the eddy current effects on a magnetic brake system which consists of 2 pairs of magnets and a conductor are investigated by using a electromagnetic software, and the results of simulations are compared with experiments. It can be concluded how the arrangement of magnets effects on the dynamic characteristics of the eddy current brake system.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.229-241
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• 1999

The paper describes the development of the ABS(Anti-Lock Bracke Sytem) real-time simulator which is composed of the real hydraulic modulator, the brake system, and the control software. This useful too supports the development enviornment of the ABS in great flexible mamer. It offers an efficient and cost-effective method of ABS development which includes the various realistic road conditons, the vehicle characteristics , and the brake characteristics. The performance of the ABS is compared with the normal braking results. Thepresented experimental results are braking on the high friction road, thetransient friction road(high to low , low to high), the split friction road, and the high friction road with steer angle. The paper shows the effectiveness and the safety of the ABS compared with the normal brake system , and the powerful and conventient tool in developing the ABS.

• 한국항공운항학회지
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• 제25권2호
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• pp.18-24
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• 2017

Results of the experimental research are described in this thesis, which are about braking characteristics of aircraft ABS brake system with different ground conditions. Dynamo-tests were conducted with the state of the application aircraft condition and with two different ground conditions. The Braking characteristics on each ground condition were drawn from the results of occurrence of skid, braking distance and deceleration. The braking performance of the application aircraft could be anticipated and the efficient range of braking operation could be set with those results.