• Proceedings of the KSR Conference
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• 2003.10c
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• pp.558-567
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• 2003

The catenary wires are damaged by periodic running of train as well as repeated stress. The wires are also degraded by atmosphere corrosion at fields. Corrosion of wires increased surface roughness and deteriorated mechanical properties by providing fatigue crack initiation sited resulting in a bad effect on service life of the wires. Fatigue test of catenary wires performed to estimate service lifetime. Also, simulation to analyze stress on catenary wires was conducted through modelling the finite elements for dynamic behaviors of wires. Fatigue life of catenary wires was estimated with fatigue and simulation tests.

• Journal of the Korean Society for Railway
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• v.5 no.1
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• pp.32-39
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• 2002

As most railways are gradually electrified with modernized electric cars, the demand for catenary wires and their facilities are also increased. Catenary Wires are exposed to the marine area with air-borne salt or severely polluted industrial area with much corrosive emission gases depending on the locations. Corrosion of catenaty wires can make their actual lifetime shorter than that originally designed. Thus, the messenger and ACSR wires, kinds of catenary wire system, were investigated with respect to corrosion, which include new and used ones collected at the field. Tensile strengths and elongations appeared to decrease when the wires were exposed to corrosive environments. The amount of decrease was more prominent as environmental conditions became more corrosive. They are also vibrated with some amplitude everytime pentographs touch contact line. The frequent cyclic load on the wire may result in a fatigue damage. Surface damage by corrosion can make fatigue crack initiate with ease. In the present study, the fatigue life of the used wire was measured 50 to 60% compared with that of new one in average.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.139.1-146
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• 2001

Contact lines are necessary to supply electric locomotives with electric power. As most railways are gradually electrified with modernized electric cars, the demand for catenary wires and their facilities are also increased. Catenary wires made by metallic materials are generally used in the open air. They are exposed to the marine area with air-borne salt or severely polluted industrial area with much corrosive emission gases depending on the railway locations. In urban area, acid rain may cause a degradation of catenary wire system. Corrosion of catenary wires can make their actual lifetime shorter than that originally designed. Thus, the messenger wires, a kind of catenary wire system, were investigated with respect to corrosion, which include new and the used one collected at the field. They are also vibrated with some amplitude everytime the train passes through the railway. The frequent cyclic load on the wire any result in a fatigue damage, Surface damage by corrosion can make fatigue crack initiate with ease. In the present study, the fatigue life of the used wire was measured 40 to 50% shorter than that of new one in average.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.265-272
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• 2001

Dynamic characteristics of catenary system for KTX Korean high-speed trains are investigated. A simulation program based on the finite element models of the catenary is developed. The influences of the various design parameters on the vibrational responses of the catenary are determined. The main design parameters include tension on the contact and messenger wires and the stiffness of the droppers connecting the two wires. The vibrational responses are primarily determined by the reflections of the propagating wave, and the dropper stiffness is found to be the dominant factor that influences overall dynamic characteristics of the catenary.

• Journal of the Korean Society for Railway
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• v.7 no.1
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• pp.14-19
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• 2004

The effect of surface damage on fatigue properties of catenary wires were investigated to estimate their service lift. As surface defects of the wires caused by surface corrosion increase, surface roughness gets worse, and as roughness increases, it is easy for moisture coming from rain and dew to be condensed around uneven parts of the surface. The condensed moisture causes a locally severe corrosion which leads to damage of the wires. Corrosion of catenaty wires can make their actual lifetime shorter than that originally designed. The amount of decrease was more prominent as environmental conditions became more corrosive. They are also vibrated with some amplitude everytime pantographs touch contact line. The frequent cyclic load on the wire may result in a fatigue fracture. Surface damage by corrosion can make formation of crack initiation at fatigue. In the present study, the fatigue life of the used wire was measured 35 to 50% compared with that of new one in average.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.525-532
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• 2005

Fatigue life of catenary wires in various environments is reduced when stress is concentrated on some points, which are often found in corroded areas by surrounding pollutants. Therefore, the fatigue test were performed in order to investigate the effect of the surface corrosion on the destructive behavior in service environment and accelerated corrosion environment as well as th examine the corrosive property and mechanism of the catenary wires. In the fatigue test of the messenger stranded wire, the corrosion degraded materials showed 35~50% of fatigue life at a same stress amplitude compared to original material. Because the catenary wires have variable load by the interaction of periodic contacts with pantographs the maximum stresses of trolley wire and messenger wire calculated by simulation at the messenger wire during operation was estimated thought the corrosion behavior interpretation of variable stress and fatigue test.

• Journal of Mechanical Science and Technology
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• v.17 no.6
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• pp.860-869
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• 2003

Dynamic characteristics of a catenary that supplies electrical power to high-speed railway is investigated. The catenary is a slender structure composed of repeating spans. Each span is in turn composed of the contact and messenger wires connected by the hangers in regular intervals. A finite element based dynamic model is developed, and numerical simulations are performed to determine the dynamic characteristics of the catenary The influence of the structural parameters on the response characteristics is investigated. The structural parameters considered include tension on the contact and messenger wires, stiffness of the hangers, and the hanger and span spacing. The hanger characteristics are found to be the dominant factors that influence the overall dynamic characteristics of the catenary.

• Journal of KSNVE
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• v.11 no.2
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• pp.346-353
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• 2001

In this study dynamic characteristic of catenary system that supplies electrical power to KTX Korean high-speed trains are investigated. A simulation program based on 3-span and 6-span finite element models of the catenary is developed. The influences of the various design parameters on the dynamic responses of the catenary are determined. The main design parameters include tension on the contact and messenger wires and the stiffness of the droppers connecting the two wires. The vibrational responses are primarily determined by the reflections of the propagating wave, and the dropper stiffness is found to be the dominant factor that influences overall dynamic characteristics of the catenary.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.176-184
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• 1999

Dynamic characteristics of pantograph-catenary system that supplies electrical power to high-speed trains are investigated. A simple catenary is composed of the contact and messenger wires connected by hamgers possessing bi-directional stiffness properties. The influences of parameters that determine the contact properties of pantograph-catenary system are investigated through numerical simulations. For the catenary, a finite difference model composed of 10 spans is constructed. The contact and messenger wires are modeled as strings with respective tension and damping ratio values. The pantograph is modeled as a linear 3-degree-of-freedom system. It is found that the tension, number of hangers and damping ratios as well as the speed of the train significantly influence the contact forces and contact separation rate

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.981-986
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• 2002

ACSR of the catenary wires is corrosion degradation progressed by the effect of atmospheric pollution. ACSR which consists of galvanized steel stranded aluminum. The inside of Steel Reinforced is hot-dipped zinc coating steel wire and it takes charge of tension. If ACSR is exposed in atmosphere, the galvanic corrosion is occurred because it is contacted with aluminum. It is occurred the chemical reaction rapidly so that the local a defect is also occurred. If the catenary wires are exposed in atmosphere of pollution conditions, it may cause to reduce the mechanical strength by corrosion degradation and may cause to damage the wires by micro cracks. Accordingly, this study presents the effects of mechanical properties through the corrosion of ACSR.