• 베이커리
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• no.4 s.381
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• pp.70-71
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• 2000

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.623-630
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• 2012

Formation used as trackbed foundation for providing vertical bearing capacity onto rail foundation are composed of crushed stones usually with certain type of grain size distribution. Permanent deformation in trackbed foundation can be generated by increasing number of load repetition due to train traffic increases, causing track irregularity. In this study, a specially prepared trackbed foundation materials (M-40) used in Korea has been tested using a large repetitive triaxial compression apparatus in order to understand resilient and permanent deformation characteristics of the material. From these test results, resilient and permanent deformation characteristic are analyzed so that a permanent deformation model is developed which can consider number of load repetition N, confining stress (${\sigma}_3$), shear stress ratio(${\tau}/{\tau}_f$) and stiffness of the material.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.9-11
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• 2005

영구자석형 선형발전기의 설계에 있어서 주로 고려되어야 할 사항은 영구자석, 철심형 치 및 코일의 형상 설계이다. 또한 영구자석과 철심형 치의 상호 작용에 의한 디텐트력은 기기의 안정적인 성능을 위해 저감되어야 한다. 본 논문에서는 1kW급 왕복 구동 평판형 선형 발전기의 영구자석과 치의 구조에 따른 디텐트력과 역기전력의 변화를 유한요소법을 이용하여 해석하였고, 디텐트력의 저감을 위해 다양한 구조의 영구자석과 치 형상이 적용되었다. 기기 구조의 변화는 역기전력에도 영향을 끼치므로 적용된 설계안 중 역기전력의 손실을 최소화할 수 있도록 설계안의 적절한 선택이 필요하다.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.73-75
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• 2009

매입형 영구자석 동기 전동기(IPMSM)은 다른 타입의 기기들 보다 많은 고조파 자속밀도 성분들을 가진다. 그러므로, 고속 영역에서의 고조파 철손을 계산하는 것은 그만큼 중요하다. 본 논문은 구동 조건을 고려한 IPMSM의 철손을 해석하였다.

• 한국도로학회:학술대회논문집
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• 2010.03a
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• pp.75-80
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• 2010

• Proceedings of the Korean Magnestics Society Conference
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• 2013.12a
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• pp.13-14
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• 2013

• Proceedings of the Korean Magnestics Society Conference
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• 2016.11a
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• pp.17-17
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• 2016

• Journal of the Korean Society for Railway
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• v.17 no.2
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• pp.123-132
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• 2014

In this study, permanent deformation of asphalt trackbed was investigated by performing repetitive load test on specimen made with dense graded asphalt mixture that was specially prepared for asphalt trackbed foundation. The obtained test results were compared with those computed from the prediction model proposed by AASHTO 2002, called MEPDG. No prediction model adaptable only for permanent deformation of the asphalt trackbed foundation has yet been developed, so the prediction model by AASHTO was adapted in this study to simulate permanent deformation of trackbed foundations in asphalt slab track and in ballasted asphalt track. In order to simulate permanent deformation, a finite element analysis was performed to obtain stresses generated in trackbed due to wheel load. It was found that the predicted permanent deformation was much smaller than the anticipated deformation and that the asphalt track could be stable during the service life of the structure.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.41-50
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• 2011

It is well-known that pavement is easily damaged by several factors including permanent deformation and fatigue crack, causing service life of the pavement to be shorter than expected. It is very important to predict amount of permanent deformation for designing pavement and developing design method of pavement. A new model of permanent deformation of pavement materials based on concept of shear stress ratio has been proposed because the lower pavement materials are highly affected by shear strength of the material. In this study a large repetitive triaxial load test has been adapted for performing test of permanent deformation of crushed subbase materials. The test procedure which includes concept of shear stress ratio has been newly developed. Several important model parameters can be obtained from the test that can be used for making correct permanent deformation model of the material.

• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.227-232
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• 2009