• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.27 no.2
• /
• pp.162-167
• /
• 2017

The chevron rubber spring is used for subway vehicle as a primary suspension. Generally, the primary suspension has an influence to the running performance and not so much effect on the ride comfort in railway vehicle. But the stiffness of chevron spring is harder and harder as time goes on because of rubber characteristics. Therefore the dynamic characteristics such as ride comfort and derailment coefficient should be reviewed according to the stiffness variation of chevron rubber spring. In this paper the effect of chevron rubber spring on dynamic characteristics was studied by considering multi-body dynamics of railway vehicle on one straight line and seven curved lines.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.3
• /
• pp.43-52
• /
• 2010

In this study, the shapes of the wheel and rail are represented by using 3-dimensional surface functions with surface parameters and a 3-dimensional wheel-rail contact analysis is presented. A whole numerical solution of wheel-rail contact at tread and flange including 2-point contacts can be achieved with the proposed numerical algorithm. Kinematic characteristics such as variances of vertical displacement and roll angle, and variance of wheel radius difference for arbitrary yaw and lateral displacement of wheelset, are determined for the KTX wheel-rail pair as an example. The condition of yaw and lateral displacement occurring 2-point contacts to analyze derailment are compared between standard and worn wheels. Differences of contact characteristics between curved and straight rails are also analyzed.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1858-1863
• /
• 2007

Railway systems are one of the best mass transit systems and many people have prevented incidents/accidents and reduced fatalities remarkably. Especially we have tried analyzing and finding the measures to prevent catastrophic accidents like train collision, derailment and fire because of their severities. It is important to assess the safety performances of railway systems like crash-worthiness analysis, body, derailment affecting factor analysis and so on for reducing and finding out the reasonable causes of disastrous accidents. In this paper the refined top-level system requirements to build-up national infra for assessing railway safety performance and the procedures and methodology for reviewing, verifying and validating infra requirements are explained. Basically the authors have used system engineering processes to analyze and verify the requirements and installation procedures and have tried maximizing the practicality of the various safety assessment systems.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.3
• /
• pp.84-89
• /
• 2001

Studied in this paper was the vehicle dynamics simulation for development of single axle bogie using the multi-body dynamics simulation program(VAMPIRE). Single axle bogie vehicle is to the crew of freight vehicle. Method of analysis for dynamic behaviors of vehicle having single axle bogie was carried by UIC(International Union of Railways) code 518 and results of analysis were presented in terms of the hunting stability and the derailment ratio and the sum of wheel/rail lateral force. The results of analysis meet the criteria proposed by UIC.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.363-364
• /
• 2006

The important factor to evaluate the running safety of a railway vehicle would be the interaction force between wheel and rail(derailment coefficient), for which is one of important factors to check the running safety of a railway vehicle that may cause a tragic accident. In this paper, when interaction force between wheel and rail happens to wheel-set of tilting vehicles, it analyzes stress distribution and verified safety.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.41-42
• /
• 2006

The important factor to evaluate the running safety of a railway vehicle would be the interaction force between wheel and rail(derailment coefficient), for which is one of important factors to check the running safety of a railway vehicle that may cause a tragic accident. In this paper, analysis of coupling term between vertical load and lateral load for install load cell to wheel-set. This result is going to be utilized in formality that verify running safety of tilting vehicles.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.7
• /
• pp.591-595
• /
• 2015

The roller rig tester for safety performance evaluation of wheel derailment is a test facility which can give the test load condition to the test wheel, similar to the actual dynamic condition in actual running condition. This study describes the evaluation result on the durability of the resilient wheel equipped with the ring damper and the damping material, and installed in the half part of a full scaled bogie in combination with the primary spring when it rotates under the dynamic condition. The evaluation result on durability of resilient wheel after load test of 2 million cycles shows that the safety of wheel is not affected by the applied load in visual inspection and nondestructive test, however, in the bolt used for fastening the ring damper to the wheel the loosening was found. Accordingly the use of self-locking nut and washer is recommended.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.10
• /
• pp.993-1001
• /
• 2007

An analysis model has been developed to assess running safety of railway vehicle passing curves. By using ADAMS/Rail, a computer analysis has been conducted by changing various parameters according to the track conditions. Analysis results show as follows: A derailment coefficient of left wheel was increased according to increase of cant at low speed, while it was decreased as increase of cant at high speed. A unload rate of left wheel was also increased according to increase of cant at low speed, while it was decreased as increase of cant at high speed. A wear number of left wheel was increased according to increase of cant at all speed, but only at 35 m/s, it was decreased as increase of cant. A friction coefficient of left wheel was Increased according to increase of cant at all speed, but only at 35 m/s. it was decreased as increase of cant.

• Journal of the Korean Society for Railway
• /
• v.10 no.4
• /
• pp.381-387
• /
• 2007

In this paper, crashworthiness of the EMU carbody of Incheon Metro is numerically evaluated against two types of overhead line structures (headspan and portal-type). The material of the EMU carbody is stainless steel (SUS301L), and that of the overhead line structures is the structural steel (SS400). The EMU carbody is analyzed under collision conditions, such as upright side-on impact, side-on roof impact and angled roof impact scenarios, to be collided against the headspan type or the portal type at the speed of 64.4km/h, respectively. It is concluded from the numerical results that the overhead line structures will not do so much harm to the EMU carbody of Incheon Metro for various collisions caused by derailment. Furthermore, the overhead line structure of the portal type is superior to that of the headspan type in the crashworthy point of view.

• International Journal of Railway
• /
• v.5 no.4
• /
• pp.156-162
• /
• 2012

When a vehicle passes through turnout, it is required to minimize the changes of lateral force for running safety of vehicle. Therefore, it is necessary to analyze interaction between the vehicle and the turnout in order to estimate the lateral force and the derailment coefficient on the turnout. In this paper, analysis model of the vehicle and turnout are established and analysis is carried out when the vehicle passes through turnout in order to improve running safety of the vehicle on turnout. To verify the vehicle and turnout analysis model, the contact points between wheel and rail and the influence of changing cradle and tongue rail are also discussed.