• The KIPS Transactions:PartA
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• v.17A no.1
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• pp.19-26
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• 2010

As standard of living is higher and aging society is coming, it is needed to develop transportation that is easy to use for weak person. To comply with the demands, it is started to make Bi-modal Tram that is on KRRI(Korea Railroad Research Institute)'s hands. This tram has to have good accessibility like bus, be low level from ground like subway, and park accurately so wheel chair's or passenger's foot can't fall into the gap. But Bi-modal Tram have long length, so it need development of All Wheel Steering System. The Bi-modal Tram that have all wheel steering system steer not only the first axle but also the second and third axle from the first axle or articulation angle, and velocity, and so on. At this study, we discuss AWS ECU's development process.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.405-407
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• 2000

The most generally implemented method to detect the ground speed of the railway vehicles is to use the rotary type speed sensor attached to wheel axle. The Slip or sliding phenomenon on the railway vehicles occurs frequently caused by the weak viscosity of the wheel. Thus, precisely to control the car, the slip/sliding detection system is required. In this paper we proposed for the speed data management system, which uses rotary type speed sensor. Proposed speed management system can detect the slip/sliding with wheel axle as well as correct the generated speed error during in error time, to provide accurate speed and precise location data. The effectiveness for adapting to the railway system is clarified by the computer simulation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.67-76
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• 1992

A procedure to determine the axle load limits of asphalt concrete pavements are proposed in this study. Axle load limits are determined by calculating maximum tensile strains at the bottom of the asphalt stabilized base layer and maximum vertical strains at the top of the subgrade. In order to investigate the efficiency of axle configuration, calculated influence line of wheel load on domestic expressway pavement system is used. Limiting strains are selected through the analysis of conventional failure criteria. From the analysis of axle load limits about axle composition(single-axle, tandem-axle, tridem-axle), it is found that the axle load limits of tandem-axle and tridem-axle can be calculated by muitipling the axle load limits of single-axle by axle numbers and that axle load limits are closely related to the thickness of each layer of pavement structure. It is also found that the axle load limits by tensile strains are more critical than those by vertical strains on asphalt concrete pavement models of YOUNG-DONG, KYONG-IN and KYONG-BU expressways.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.84-89
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• 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 KSME Conference
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• 2008.11a
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• pp.459-463
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• 2008

Induction hardening has been used to improve torsional strength and characteristics of wear for axle shaft which is a part of automobile to transmit driving torque from differential to wheel. After rapidly heating and cooling process of induction hardening, the shaft has residual stress and material properties change which affect allowable transmit torque. The objective of this study is to predict the distribution of residual stress and estimate the torsional strength of induction hardened axle shafts which has been residual stress using finite element analysis considered thermo mechanical behavior of material and experiments. Results indicate that the torsional strength of axle shaft depends on the surface hardening depth and distribution of residual stress.

• Physical Therapy Korea
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• v.10 no.2
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• pp.1-10
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• 2003

This study was carried out to help the comprehensive rehabilitation of spinal cord injuries by measuring propulsion force and endurance exerted on wheelchair handrims, and predicting the differences among three different rear axle positions. The BTE (Baltimore Therapeutic Exerciser) work simulator was used on 9 paraplegia to test the force and endurance during wheelchair propulsion. The 141 large wheel of the BTE work simulator and a standard wheelchair with removed handrims were used for simulating wheelchair propulsion. The neurological and demographical characteristics of the patients were collected by personal interviews and direct examinations. The Kruskal-Wallis test was used to compare force and endurance among the groups. The strongest maximum isometric strength was produced when the rear axle of the wheelchair and the acromion process were on the same coronal plane. Although there were no significant differences statistically, moving the rear axle forward did result in greater isotonic strength. The research suggests that better functional activity of persons with paraplegia is possible when the rear axle of the wheelchair is appropriately adjusted.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.88-94
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• 2012

An axle drive shaft with double joint shaft, cross kit and yoke has an important role by transferring power and changing steering angle between axle and wheel in power train system. It has been used widely in the heavy machinery requiring a high reliability in the power train system. At fatigue failures of the axle drive shaft with the long span, a relatively high stress concentration at a snap ring groove on the drive shaft brings to significant fatigue damages under repeated loading condition. As Peterson's suggestions on this study, a relief groove in the vicinity of the snap ring groove is applied by decreasing the stress concentration and improving the fatigue life of axle drive shaft. By using FEM analysis, the decreasing effect of the stress concentration and extended fatigue life are due to the change of design parameters related with size and location of the relief groove. The relief groove with the design parameters such as d/b=2.0 and r/h=1.2 enables to decrease the stress concentration of 22.3% and increase the fatigue life more than 3 times by comparing with no relief groove application.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.668-673
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• 2003

A wheel and axle failure can cause a derailment with its attendant loss of life and property. The service conditions of railway vehicles have become severe in recent years due to a general increase in operating speeds. Damages of railway wheel are a spalling by wheel/rail contact and thermal crack by braking heat etc. One of the main source of damage is a residual stress. therefore it is important to evaluate exactly. A Residual stress of wheel is formed at the process of heat treatment when manufacturing. it is changed by contact stress developed by wheel/rail contact. Distributions of residual stress vary according to a magnitude of wheel load, a magnitude of friction when acceleration and deceleration. The objective of this paper is to estimate the influence of wheel motion on the residual stress distribution in the vicinity of the running surface.

• Journal of the Korean Society for Railway
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• v.6 no.2
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• pp.142-148
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• 2003

A wheel and axle failure can cause a derailment with its attendant loss of life and property. The service conditions of railway vehicles have become severe in recent years due to a general increase in operating speeds. Damages of railway wheel are a spatting by wheel/rail contact and thermal crack by braking heat etc. One of the main source of damage is a residual stress. therefore it is important to evaluate exactly. A Residual stress of wheel is formed at the process of heat treatment when manufacturing. it is changed by contact stress developed by wheel/rail contact. Distributions of residual stress vary according to a magnitude of wheel load, a magnitude of friction when acceleration and deceleration. The objective of this paper is to estimate the influence of wheel motion on the residual stress distribution in the vicinity of the running surface.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.301-306
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• 2011

The rear of the vehicle generally overhangs the rear axle. As a result, the rear of a vehicle swings to the outside of the rear axle(rear swing-out). In front steering vehicles, rear swing-out is not important because rear swing-out values measured outside the rear edge are relatively small. However, in the case of the bimodal tram with AWS(all wheel steering), the rear swing-out values increase because of the rear steering at a reverse phase angle. Off-tracking is defined as the radial offset between the path of the centerline of the front axle and the path of the centerline of the following axle. In this paper, in addition to determine the turning performance of bimodal tram with AWS, turning radius, swing-out, off-tracking and swept path width were also investigated.