• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.83-90
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• 2012

Driver ordinarily takes sudden braking when urgent situation is developed or when the vehicle is involved in an unexpected accident. Therefore, the most common trace at a traffic accident scene is skid mark. Currently, in investigating traffic accident, overspeed is determined by the length of skid mark. However, in order to identify accurate cause of accident, estimation of pre-braking speed which takes into account speed reduction during transient time should be considered as a requirement. In a recent study, several ways to estimate pre-braking speed were suggested, but none considered to differentiate the decelerating transient brake section and skidding section. This study analyzed trends of decelerating transient brake section and skidding section by real braking test.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.77-84
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• 2000

Nonlinear transient analysis is executed to obtain the temperature distribution, and to evaluate the thermal stress of brake drum by using FEA(finite element analysis). The result induces the reason why hair crack and the cause of drum failure occurs and the way how stress of drum decreases. The temperature of drum is in proportion to the drum thickness and it processes nonlinear changes at every points of drum. The higher bulk temperature raises, the more stress difference between inner surface and outer surface makes and the highest bulk temperature is at the corner section. It is necessary for the diminishment of the drum stress to make air flow, between drum and rim, move lively and use the materials of higher conductivity. The hair crack and the cause of drum failure seem to be started at the near corner section.