• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 추계학술대회논문집A
• /
• pp.87-92
• /
• 2000

In this paper, we investigated the braking performance of a composite brake shoe for power car. Laboratory bench test and field tests were carried out to characterize the braking performance by the parameters such as friction coefficient, wear rate, braking temperature and stopping distance. Density distribution was found to have a significant influence on the wear rate. The composite brake shoe with even density distribution showed better braking performance. The braking performance of a composite brake shoe was also compared with that of a cast iron brake shoe which is currently being used. The result indicated the performance of the composite brake shoe is better than the cast iron brake shoe.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 추계학술대회 논문집(III)
• /
• pp.377-382
• /
• 2003

In tread braking of freight cars, braking force is produced by the friction between the wheel and the braking shoe. Friction coefficients such as the brake power, weight variation and brake shoe types should be sensitively treated as the design parameters. The conditions of the car, empty and weighted, should also be taken into consideration in brake force design and the control of brake force has some limitations in terms of the brake system design so that the brake materials selection should be considered as important measures to solve that difficulties. Friction characteristics of brake materials should remain within the range of maximum and minimum value and the friction performance should remain stable regardless of braking time and temperature. This study presented an experimental evaluation method to secure optimum braking performance by keeping safe braking effect and braking distance by the friction coefficient of the brake shoe of the freight cars.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1999년도 추계학술대회 논문집
• /
• pp.385-390
• /
• 1999

In this paper, we investigated the wear rate, braking temperature and stopping distance of the composite brake shoe for diesel locomotive in the field test. The wear rate and braking temperature of the composite brake shoe would rather than cast iron. Also, the stopping distance of composite brake shoe is 450m at 100km/h. This result of field test shown that the density distribution of the composite brake shoe influence on wear rate.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2011년도 춘계학술대회 논문집
• /
• pp.1307-1308
• /
• 2011

• 한국운동역학회지
• /
• 제23권4호
• /
• pp.377-385
• /
• 2013

Fall is very fatal accident causes death to older people. Shoe may affect to fall. Shoe influences risk of slips, trips, and falls by altering somatosensory feedback to the foot. The purpose of this study was to investigate the analysis of non-slip shoes for older people and influence on older people's lower extremity. For this study twenty three healthy older people were recruited. Each subjects walked over slippery surfaces (COF 0.08). Four pairs of non-slip shoes (shoe A had the greatest COF, 0.23 while shoe B, C, and D had smaller COF relatively) for older people were selected and tested mechanical and biomechanical experiment. For data collection motion capture and ground reaction forces were synchronized. There were statistically significant differences for slip-displacement, coefficient of friction, braking force, propulsion force, knee range of motion and knee joint stiffness by shoes. It was concluded that shoe A was the best for non-slip function because of the lowest slip displacement, the highest braking and propulsion forces, and the highest mechanical and biomechanical coefficient of friction where as shoe B, C, D were identified as a negative effect on the knee joint than shoe A. To prevent fall and slip, older people have to take a appropriate non-slip shoes such as shoe A.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2005년도 추계학술대회 논문집
• /
• pp.101-106
• /
• 2005

During braking at a train, thermal energy is generated due to the frictions between disk and lining and wheel and shoe. In general, the braking transfers the kinetic energy into thermal energy. Therefore. the frictional characteristics are varied according to the braking force, the thermal resistance, and the thermostable, etc. Using a Dynamo testing we have studied the frictional characteristics and the thermal distribution to investigate a stable speed and to improve the testing method through comparing and analysing in the measurement or the thermocouple temperature and infrared camera.

• 한국산학기술학회논문지
• /
• 제11권4호
• /
• pp.1178-1185
• /
• 2010

철도차량의 고속화가 가속화되면서 화물을 운송하던 컨테이너 차량이 차륜의 파손에 의하여 탈선하는 사고가 발생하여 많은 물적 피해가 발생하고 있으며, 이러한 철도차량의 사고는 많은 인명 피해와 물적 피해를 가져오는 대형 사고로 발전할 수 있다. 따라서 이에 대한 재발 방지를 위한 차륜의 파손 해석에 대한 연구가 필요한 실정이다. 철도차량의 차륜은 기계적 하중과 열하중를 동시에 받으며, 기계적 하중으로는 철도차량의 무게에 의한 수직하중과 곡선 구간을 운행할 때 차륜과 레일의 접촉부에 수평하중이 발생하며, 철도차량의 제동시 답면제동에 의한 반복적인 열하중을 받는다. 이러한 차륜에 발생하는 기계적 하중과 열하중은 차륜의 균열과 잔류응력 등을 발생시키는 것으로 알려져 있다. 따라서, 본 연구에서는 차량 주행 시의 브레이크 이력과 하중 조건을 고려한 열 구조 연성해석을 수행하여 차륜에 부하되는 최대응력을 추정하였으며, 이 값을 파괴역학 파라미터인 응력확대계수에 적용하여 차륜의 안전성을 평가하였다.

• 한국운동역학회지
• /
• 제21권1호
• /
• pp.9-16
• /
• 2011

The purpose of this study is to analyze the effects of both various shoe types and bare feet on ground reaction force while walking. Ten first-year female university students were selected. A force platform(Kistler, Germany) was used to measure ground reaction force. Six types of shoe were tested: flip flops, canvas shoes, running shoes, elevated forefoot walking shoes, elevated midfoot walking shoes, and five-toed shoes. The control group was barefooted. Only vertical passive/active ground reaction force variables were analyzed. The statistical analysis was carried out using the SAS 9.1.2 package, specifically ANOVA, and Tukey for the post hoc. The five-toed shoe had the highest maximum passive force value; while the running shoe had the lowest. The first active loading rate for running shoes was the highest; meanwhile, bare feet, the five-toed shoe, and the elevated fore foot walking shoe was the lowest. Although barefoot movement or movement in five toed shoes increases impact, it also allows for full movement of the foot. This in turn allows the foot arch to work properly, fully flexing along three arches(transverse, lateral, medial), facilitating braking force and initiating forward movement as the tendons, ligaments, and muscles of the arch flex back into shape. In contrast movement in padded shoes have a tendency to pound their feet into the ground. This pounding action can result in greater foot instability, which would account for the higher loading rates for the first active peak for padded shoes.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 추계학술대회 논문집
• /
• pp.55-58
• /
• 2005

During braking at a train, thermal energy is generated due to the frictions between disk and lining and wheel and shoe. In general, the braking transfers the kinetic energy into thermal energy. Therefore, the frictional characteristics are varied according to the braking force, the thermal resistance, and the thermostable, etc. Using a Dynamo testing we have studied the frictional characteristics and the thermal distribution to investigate a stable speed and to improve the testing method through comparing and analysing in the measurement of the thermocouple temperature and infrared camera.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2013년도 춘계학술대회 논문집
• /
• pp.486-491
• /
• 2013

Creak noise is kind of scratching noise which is usually generated in drum brake system on the vehicle. When driver brakes vehicle or applies parking lever, drum brake shoe moves to the drum side to stop the vehicle. And at that time, moving shoe scratches backing plate ledge surface, and that makes scratching noise in special condition. This study presents how we can generate creak noise in the laboratory and how we can reduce it by experimental approach. Through several and various type of tests, we could generate creak noise with damage on ledge area of the backing plate in the lab and we verified tab type shoe design can reduce this scratching noise. As a result of this study, we notified how creak noise happens in the vehicle, and that tab type design shoe has good performance of ledge area damage based on lab test(rig & dynamometer equipment), and that this can reduce potential risk of creak noise in the field.