A study on running stability assessment methods for 1/5 small scaled bogie of saemaul using small-scaled derailment simulator

摘要

The running stability of railway vehicle has been one of the important pending issues of railway operators and organizations. Especially the dynamic stability has become more important in terms of securing safety since vehicles are running faster than before. Currently the dynamic stability assessment is being conducted by usingtest equipment such as roller rig. However, full scale roller rig is not cost effective and inconvenient to achieve diverse design parameters. To marginalize the drawbacks, a small scale simulator has been used butthe technique for the design of the small scale simulator for the fundamental study about the dynamic characteristics of the wheel-rail system and the bogie system has not been well developed. Several researchers had produced 1/5 small scaled bogie model and analyzed critical speed by applying a creep theorybut the related studies did not carefully describe all of factors including suspension characteristicsthat have a large effecton small scaled bogie’s dynamic characteristics. Therefore the research about the development of the small scale simulator and the assessment method of the bogie dynamics has been required. This study presents the assessment method of 1/5 small scaled bogieusing small-scaled derailment simulator to predict dynamic stability of the railway vehicle. The results show that the characteristics of the small scaled bogie’s major modes obtained at the running speed of 40km/h on the small-scaled derailment simulatorweresimilar to the mode analysis results and this means thatthe obtained results from the small scaled simulator could be used to assess the dynamic characteristics of the vehicle with a support from the analytic model. It was also found that the theoretic hunting motion frequency of the 1/5 small scaled bogie was similar to thefrequency obtained on the simulator. These results mean that the small-scaled derailment simulator could reproducethe wheel/rail interface characteristicsand could be used for running stability assessment through the analytic model considering relevant similitude rule.