• Proceedings of the KSME Conference
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• 2008.11a
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• pp.384-389
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• 2008

An accelerated fatigue test is essentially required to maintain the reliability of the actual structure of KTX under operation conditions. However, actual fatigue life cannot be obtained if specimens are not adequate to the conventional fatigue test. Moreover component maker did not provide data of loading stress (S) - cycles at the failure (N). In this study, we suggest a prediction method of the S-N curve for establishing an accelerating test under various load levels. Load history was acquired from the field tests. A Rainflow method was used on the cycle counting of the field load data, and then, an S-N curve was obtained through the iteration process under the condition that the damage index satisfies to 1 in the Miner's rule.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.137-143
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• 2012

This study analyzes flywheel through the analyses of stress, fatigue and vibration. Maximum equivalent stress is 15.271MPa at the mid round shape and maximum deformation is 0.02264mm at the outer teeth. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of -$10^4$MPa and the amplitude stress of 1000 to 2900MPa, the possibility of maximum damage becomes 30%. This stress state can be 20 times greater than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The range of natural frequencies becomes 200 to 820Hz and the values of these deformations are not more than 10mm. The structural result of this study can be effectively utilized with the design of flywheel by investigating prevention and durability against its damage.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.1-8
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• 2013

This study investigates life and damage due to structural and fatigue load at speaker placer with wall hanger type. As the small stress and deformation are shown at the models of A, B and C shapes on structural analysis, there is no problem at installing speaker placer. As the largest stress is happened at the middle part of joint on the models of A, B and C shapes, this part must be considered at the design. A shape is thought to have most fatigue damage among 3 shape models. C shape model has most excellent, but A model has least at fatigue durability. This study result is applied with the design of speaker placer and it can be useful at predicting prevention and durability against its damage.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.208-213
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• 2015

In this study, two models due to the configuration of caliper cylinder among the parts of automotive brake system are studied by structural and fatigue analysis. As the maximum equivalent stress at model 2 becomes 1.5 times lower than model 1, model 2 can endure load higher than model 1. In case of fatigue damage analysis on model 1 and 2, model 1 has the damage area more than model 2. Fatigue damage at model 1 happen more than model 2. These study results can be effectively utilized with the design on caliper cylinder by anticipating prevention against its damage and investigating durability.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.1
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• pp.137-144
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• 2013

This study analyzes structural analysis with fatigue and natural frequency on ATV knuckle. The maximum equivalent stresses are happened at the end of knuckle in case of model 1, 2 and 3. As these stresses are below the allowable stress, these models can be stable structurally. The fatigue damage possibility at model 1 becomes more than model 2 and 3. Model 2 or 3 has more durability than model 1 at fatigue. As the resonances are happened at the frequency more than 2000 Hz in case of model 1, 2 and 3, there is no resonance possibilities at real driving. Prevention against damage and durability prediction on automotive chassis parts can be effectively improved by applying this study result on knuckle and improving structural strength.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.242-243
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• 2014

본 연구는 윈도우 커버 뒷면에 2층 구조의 전극으로 각 전극들의 상호 정전용량을 이용한 터치스크린 패널을 개발하였다. 정전용량 방식의 터치스크린패널(Touch Screen Panel; TSP)은 필름을 사용하는 저항막 방식에 비해 내구성이 좋아 작은 손상에도 동작에 지장이 없다. 또한, 터치의 정확도가 높고, 광학적 특성이 우수하며 다중 포인트가 가능하다. 윈도우 일체형 TSP는 박막증착을 통해 X축,Y축 방향의 전극 패턴을 형성하였고 전극 교차부는 포토리소그래피공정을 통해 절연막 형성 및 Bridge, Bezel 전극을 형성하여 TSP를 제조 하였다.

• Journal of the Korean Chemical Society
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• v.41 no.11
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• pp.575-580
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• 1997

Benzyl viologen was synthesized and the electrochromic properties was examined. At an applied voltage of 2.6 V the electrocoloration was appeared but electrooptical response abruptly decreased after a certain period of time. It was a cause that the quality of the ITO film was degraded, e.g. the conductivity of the ITO film reduced from the original value. The ITO surfaces under some different conditions were observed by XRD and SEM.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.2
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• pp.8-13
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• 2013

This study analyzes about poclain bucket through fatigue durability analysis. Maximum equivalent stress and total deformation are shown at the lower of bucket and edge part respectively. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of -10000Pa to 5000MPa and the amplitude stress of 0 to 6000MPa, the possibility of maximum damage becomes 3%. This stress state can be shown with 5 or 6 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of poclain bucket by investigating prevention and durability against fatigue damage.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.239-244
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• 2011

This study analyzes the behaviors on stress, fatigue and vibration about bulldozer in operation. Maximum equivalent stress is shown with the frequency of 100 Hz in case of the harmonic vibration analysis applied with force. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of 0 to -105MPa and the amplitude stress of 0 to $1.617{\times}105MPa$, the possibility of maximum damage becomes 3.23%. This stress state can be shown with 5 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design of bulldozer by investigating prevention and durability against its damage.

• Computational Structural Engineering
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• v.7 no.4
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• pp.119-126
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• 1994

One of the most serious promblems in the concrete structures is cracking failure due to the several complicated reasons. These cracks are not only serious structural problems, but also lower the durability and deteriorate the structural shape, which cause the reinforcement rust in the open air and sea water. An analytical study was undertaken to investigate the cracking problems in the one of concrete caissons using Finite Element Method. This caisson is modelled with plate elements and truss elements for the walls and lifting cables respectively and analyzed in the every construction stages, such as lifting, moving, sinking, filling, towing, setting, and proposed reasonable construction methods for the concrete caisson structures.