• Journal of the Korean Society for Precision Engineering
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• v.32 no.7
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• pp.619-625
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• 2015

There is a large interest to find reliable and automatic methods for crack detection and quantification in the railway bogie frame. The non-destructive inspection of railway bogie frame has been performed by ultrasonic and magnetic particle testing in general inspection. The magnetic particle method has been utilized in the defect inspection of the bogie frame but the grinding process is required before inspection and the dust is developed resulting from the processing. The objective of this paper is to apply the inspection method of bogie frame using infra-red thermography. The infra-red thermography system using the excitation of eddy current was performed for the defect evaluation of weld specimen inserted artificial defects. The result shows that the infra-red thermography method can detect the surface and inner defects in weld specimen for bogie frame.

• Journal of the Korean Society for Railway
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• v.5 no.4
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• pp.222-230
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• 2002

The rotating bogie frame is used in the bogie for a Light Rail Train under development in Korea. In development of the bogie, the structural strength and fatigue characteristics of the rotating bogie frame have been evaluated under the predefined load cases according to the Korean standards for a urban EMU. No part of the rotating bogie frame was subjected to stress beyond the fatigue endurance limits of the material used when grinding the welding of the lower plate link. It is concluded that the rotating bogie frame is safe in view of its static and fatigure strength.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.253-260
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• 2001

Rotating bogie frame will be used in the bogie for the Light Rail Train being developed. In development of the bogie, analyzed were the structural strength and fatigue characteristics of the rotating bogie frame. Defined load cases were applied for the analysis. No part of the rotating bogie frame is subjected to stress beyond the fatigue endurance limits of the material used when grinding the weldment of the lower plate link bend. It is concluded that the rotating bogie frame is considered safe in the view of the structural strength.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.589-594
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• 2004

This paper has evaluated the fatigue strength of a tilting bogie frame for the Korean tilting train. We have established the loading combinations for the tilting bogie frame based on the UIC standard because there are no standards for the tilting train. For this study, we have derived 31 load cases to consider tilting effect. Then, we have performed the static and fatigue analysis. From this study, we can make sure the safety of the tilting bogie.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.213-218
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• 2006

For an evaluation of fatigue strength, the dynamic stress test of bogie frame for new electrical multiple unit was practiced in the real route line. And this results are summaries for a decision whether this vehicle can be operated safely for more than 25 years according to the international standard of the evaluation and its procedure.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.895-901
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• 2009

Fatigue fracture of the welded joints of bogie frames is one of unsolved problems. To improve the fatigue strength of the welded joints, various techniques have been applied. In this study, we have investigated the effect of shot peening on the fatigue characteristics of SS400 welded specimens. The fatigue lives of four kinds of welded specimens were examined; welded, PWHT, shot peened, and shot peened after PWHT. The results of the fatigue tests show that the fatigue limit of the shot-peened specimens is higher than that of the welded specimens, and the PWHT specimens have a lower fatigue limit than the welded specimens. It was found that shot peening is a very effective method to improve the fatigue strength of SS400 welded joints.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.261-266
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• 2001

Bogie frame of the electric car is an important structural member for the support of vehicle leading. In general, more than 25 years' durability is necessary. A lot of study has been carried out for the prediction of the structural integrity of the bogie frame in experimental and theoretical domains. One of the useful methods is reliability-based approach. The objective of this paper is to estimate the structural integrity of the bogie frame of an electric car, which is under the running test. We used two approachs. In the first approach probabilistic distribution of S-N curve is used. In the second approach, limit state function is used.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.461-467
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• 2000

This study proposes the integrity evaluation of bogie frame using ultrasonic waves-fractography analysis. Analysis objectives in this study are to investigate fracture planes of damaged zone by the A-scan method. The surface condition of fracture plane shows degree of degradation by stress concentration. The detection of the natural defects in bogie frame is performed using the characteristics of echodynamic pattern in ultrasonic signal. Results of ultrasonic testing agree fairly well with those of actual fracture plane. In quantitative fractography analysis, microstructures of actual fracture plane turned out to be intergranular and transgranular fracture, Proposed ultrasonic-fractography analysis in this study can be used for the integrity evaluation of the bogie frame

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.440-446
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• 2005

The truck frame of railway vehicle is important structure supporting the various loadings during running on the railway. The verification of sufficient strength on truck frame is essential in case of EMU carrying many people. To verify the safety of truck frame, the actual loading conditions should be considered ast design stage. This paper is describing that the development procedure of truck frame and bolster changed from existing casting frame to new welded frame for New-York EMU, also introducing the design regulations for new welded truck frame. Additionally the dynamic accelerations on the truck were measured to insure the actual loadings on service running condition, and the procedure and results of this test are described in this paper.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.235-239
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• 2001

The bogie of high speed freight car running on conventional line is welded bogie modeled on Y25 bogie developed in Europe. Y25 bogie has speed limit of 110km/h. But it has limiting factors to speed-up as increasing maintenance cost and friction parts pedestal. And also it was reported that cracks are found in the parts where center beam meet bolster and endbeam near bracket for braking part. This study includes stress analysis improved structure of welded bogie for strength evaluation by numerical method and experimental method. According to the study, new configuration bogie shows improvement in strength.