An Estimation of the Bogie Frame for Light Rail Transit System Experimental Research on the Fatigue Strength

초록

The term 'light' rail transit (LRT) system means lighter rail transit system compared with the heavy rail transit systems which have been operated in large cities including Seoul. The systems have medium transportation capacity between subways and bus. However, they have diversified capabilities handling of transportation demands according to the system configuration, and are known to be suitable for the branch lines of subways, main lines in small and medium cities, and between a large city and satellite cities. They are attracting interests as a new transportation means due to lower investment and operation cost, lower emission, and environment-friendliness. However, like heavy rail transit systems, they have to be available for service life of at least 25 years and subject to irregular, variable load in the operation. Therefore, it is very important to predict fatigue life under variable load for the design and evaluation of the health of the structure. In this study, the test car was driverless, rubber wheeled LRT vehicle developed by KRRI under the sponsorship of the Ministry of Construction and Transportation. The test car is running 100km/day or farther on a 2.3km long test rail to test parts durability. In this study, the fatigue strength of the bogie frame of LRT cars was estimated by applying the mean stress, which took the effect of the composite load in real running into consideration, on the service stress.