• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.213-220
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• 2003

고층의 강 모멘트저항골조에 대한 지진 반응을 살펴보기 위해서 동적해석을 실시하였다. 구조물은 세가지의 다른 설계절차로 의도적으로 설계하였고 그 세가지의 개념은 강도 지배설계, 강기둥-약보 지배설계, 횡변위 지배설계이다. 그렇게 설계한 구조물이 각각 질량비정형이 존재하도록 하여 힁변위, 소성힌지, 이력에너지 입력 및 요구응력에 대해서 토론하였다. 미래에 설계에의 응용을 위해서 최대 지반가속도로 표현한 두 등급의 지진 하중을 이용해서 이력에너지 입력요구 곡선을 제시하였다.

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.196-197
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• 2001

• Proceedings of the Korean Magnestics Society Conference
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• 2014.11a
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• pp.165-166
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• 2014

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.3
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• pp.19-25
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• 1984

In the welded structure, the most dengerous section is welded parts and almost fractures of welded structure occur from welded parts. Accordingly, in other to prevents of fracture, it is important seeking the fracture behavior of welded parts. In this study as basic investigation of fracture behavior of welded parts, it is investigated that local distribution of fracture toughness and effect of multipass electrode welding, also effect of release of residual stress were investigated, as the subjected. material, the used steel having fatigue history and unused steel were selected. As the result of this study, it is dear that the base metal of unused steel and heat affected zone and weld metal are different each other in fracture toughness, and it seems clear that the weld metal may will become source of fracture because of it having the most low fracture toughness. Especially, in the case of crack occur in the used steel, it will be the most brittle section in the structure because of it having low fracture toughness then weld metal. It affirmation that, if welded parts has not flaw, the multi pass electrode welding effective to improve of fracture toughness, also release of residual stress is none effective to improve of fracture toughness in this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.771-781
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• 1994

The heat generation of cement causes the internal temperature rise and volume change at early age, particulary in massive concrete structures. As the results of the temperature rise and restraint conditions, the thermal stress may induce cracks in concrete. Therefore, the prediction of the thermal stress is very important in the design and construction in order to control the cracks developed in mass concrete. In case of young concrete, creep effect by the temperature load is larger than that of old concrete. Thus, the effect of creep must be considered for checking the cracks, serviceability, durability and leakage. This paper is concentrated on the development of a finite element program which is capable of simulating the temperature history and the thermal stress considering creep and the modified elastic modulus due to inner temperature change and maturity. The analytical results in the inner parts highest important to control cracks are in good agreement with experimental data. Therefore this study may provide available method to control the cracks.

• Journal of Korean Society of Steel Construction
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• v.11 no.4 s.41
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• pp.329-338
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• 1999

A systematic procedure to evaluate fatigue damages and to predict remaining fatigue lives is introduced for a steel railway bridge. Fatigue damages are evaluated by using the currently available fatigue damage theory. Fatigue lives with the condition of fatigue crack initiation are estimated by the probabilistic approach based on the reliability theory as well as the simplified procedure. A equivalent deterministic procedure is also suggested to assess the remaining fatigue life under various traffic conditions. Numerical simulations are used to assess dynamic stress histories with correction factors. Loading models are obtained from the passenger volume data. Train coincidences are also considered. Based on the results, the fatigue life is found to be underestimated by without considering the coincidence of trains on the bridge. The simplified method proposed in this study are found to yield approximately the same results as the systematic procedure.

• Journal of the Korean Wood Science and Technology
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• v.16 no.1
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• pp.55-61
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• 1988

목재(木材)의 응력(應力)과 변형(變形)에 미치는 함수율 및 온도변화의 효과를 유한요소(有限要素) 분석법에 의해 측정하였다. 목재는 춘재(春材) 및 추재(秋材)를 나타내는 층구조(層構造)의 원통형(圓筒形)으로 모델화 하였으며, 선형적(線形的) 탄성체(彈性體) 그리고 원통형(圓筒形) 이력성(異方性) 재료로 가정하였다. 경단면(徑斷面)에서의 변형(變形)은 함수율 및 온도와 밀접한 관매가 인정되었으며, 최대(最大)의 압축응력(壓縮應力)은 최내층(最內層)인 만재층(晩材層)에서 일어났다. 또한 최대의 촉단면응력(觸斷面應力)은 춘재부(春材部)의 최내층(最內層)에서 일어났다. 경단(徑斷) 방향(方向)과 촉단방향(觸斷方向)의 응력간(應力間)의 차이는 외층(外層)에서 가장 크게 나타났으며 이와같은 응력(應力)의 차이가 변형(變形)을 일으키는 주요인(主要因)임이 밝혀졌다.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.161-166
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• 2001

Overconsolidated clays have a different stress history according to the deposit environment. The stress history is classified into (i) rotation angle of stress path, (ii) overconsolidation ratio, and (iii) magnitude of length of recent stress path. Stress-strain behaviour of overconsolidated clays strongly depends on these stress history. In this study a series of drained stress path tests were carried out. Test results indicated that stress-strain behaviour of overconsolidated clay(focused on strain rate) depends on OCR and length of recent stress path, especially rotation angle.

• Geotechnical Engineering
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• v.7 no.2
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• pp.5-26
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• 1991

The results of a laboratory investigation for the influence of soil sties history, relative density of sand, pile surface condition depth and diameter on the behavior of piles in uplift are presented. Ultimate Uplife capacity depends not only on the relative density of sand but soil horizontal stress. The phenomena of critical depth can be explained by change of horizontal stress with depth. The value of Ktan tends to decreases with increasing pile diameter.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.09a
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• pp.352-359
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• 2003

철도나 고속철도 교량에 사용되는 장대레일은 차량에 의한 동적충격의 완화, 주행시 승차감의 향상과 같은 장점을 가져온 반면에, 인접한 교량의 연결부에서 레일과 교량 상부구조간의 거동 불일치로 인해 레일에 부가적인 응력을 발생시킨다. 이러한 부가적인 레일응력과 지반운동의 특성에 따른 구조적 응답의 민감도 및 열차의 안전한 정지를 고려하여, 지진 발생시 고속철도교량의 장대레일 응력을 해석하기 위해 레일의 재료비선형성, 지반운동의 위상차 등을 고려한 비선형 시간이력해석 방법을 제시하였다. 그리고 우리나라의 여러 지반조건을 고려하고 고속철도의 대표적인 연속교량 모델에 적용하여 제시한 방법의 타당성을 검토하였다.