• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.129-142
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• 2005

A semi-monocoque truncated cone structure, which is a main structure for the payload adapter of KSLV-I, was designed. Static test was performed to confirm the reliability of the cone structure under the design loads. Strains and displacements are measured during four load cases; the compressive axial, pure bending, pure shear, and combined loading conditions. The results showed that the cone structure satisfies the design requirements. An equivalent axial load was applied to the cone structure so that the global buckling of the cone structure occurred. The measured buckling load was compared with the predicted one by finite element method. The results show a good agreement.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.844-850
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• 1998

본 연구에서는 개방구(opening)을 갖는 원자력발전소 강재 격납구조물의 내력을 평가함에 있어서 기존의 실용 구조설계에 적용된 개구부가 없는 원통형 쉘의 좌굴 판정 기준이 적절하지 않음을 밝혔으며, 대안으로서 개방구(opening)를 갖는 원통형 강재 격납구조물의 재료적 비선형과 기하학적 비선형을 고려한 극한 내력 해석을 수행함으로써 중기발생기 교체작업시 유발되는 인양 하중에 대한 격납구조물의 구조적 안전성을 평가하였다. 개방구를 갖는 격납구조물에 대하여 stiffner가 있는 상태에서 크레인 하중에 대한 극한 내력을 평가해본 결과 크레인 하중이 재하될 경우, 구조물이 선형 탄성 범위에 있는 것으로 확인되었으며 개방구 주위의 국부적인 항복응력도달 상태에 대하여 10.8의 안전율을 확보 할 수 있는 것으로 계산되었다. 본 연구를 통하여 제시된 개방구를 갖는 강재 격납구조물의 극한내력 평가 방법은 유사 구조물의 구조건전성 평가에 활용될 수 있을 것으로 사료된다.

• Composites Research
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• v.14 no.2
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• pp.50-59
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• 2001

The predictions of residual strength evolution and fatigue life of full scale composite rotor blade for multipurpose helicopter were studied using a strength degradation model. Flight-by-flight load spectrum was developed on the basis of FELIX standard spectrum data. The laminated structural analysis was also performed to obtain corresponding local stress and/or strain spectra for each ply of laminate skin and glass roving spar structures around the blade root where fatigue damage was severely anticipated.

• Journal of Korean Association for Spatial Structures
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• v.10 no.4
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• pp.133-140
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• 2010

This paper studies on the instability behaviour of the Seoul southwest baseball dome. The nonlinear Snapping phenomenon of the structure is investigated about the load mode by the design load of analysis structure and these combined loads. The initial imperfection obtains the buckling mode through the eigenvalue analysis of the tangential stiffness matrix and uses this for the nonlinear analysis. However, the buckling of members or the local buckling, and etc don't consider in the research range of this research task. Also it is limited the overall buckling phenomenon.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.89-93
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• 2002

One of the primary factors like plate structure in ship is redundancy structure that is comparable with ocean structure and frame structure. The more component material becomes buckling collapsed locally the less structure stiffness becomes accordingly. As a result, by increasing the load distribution of my other subsidiary structure continually component member collapses, therefore the structure could be in danger of collapse. So, in order to interpret this phenomenon precisely, the study on boundary condition of the ship's plate and post-buckling analysis must be considered In this study, the rectangular plate is compressed by the in-plane load Buckling & Ultimate strength characteristics are applied o be the elasto-plasticity large deformation by ansys code with F.E.M method On this basis, elasto-plasticity of the plain plate are investigated. This study proved elasto-plasticity behaviour of the ship's plate in accordance with boundary condition based on the series analysis in case of the compressive load operation

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.4
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• pp.35-40
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• 2005

There are many methods to reinforce the cylindrical structure for light weight design like skin-stringer and semi-monocoque. Isogrid is one of the reinforced structures to improve buckling load. Isogrid has many advantages for complex load case, internal pressure and concentrated load.In this paper, compressive buckling test and non-linear FE analysis of the isogrid panel are described. Diameter of panel is 2.4m and thickness of plate is 11.43mm. The angle which the panel accomplish is about 70 degrees and, its height is about 660mm. Local buckling, global buckling and variation of stiffness after local buckling were observed during buckling test of the panel. MSC/MARC is used for non-linear FE analysis. When analysis, initial imperfection of panel which occurred during plastic forming is considered. The results of analysis for buckling mode and buckling load have good agreements with test.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.1
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• pp.39-58
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• 2004

It is very important that predict the inelastic seismic behavior exactly for seismic performance evaluation of a building in the performance based seismic design. Evaluation method of seismic performance based on the pushover analysis reflected in PBSE was developed by some researchers. For the evaluation of inelastic global and local seismic responses by pushover analysis exactly. lateral load distribution should be adjusted and reflected the dynamic characteristics of structural system and various seismic ground motions. And performance point should be determined based on the evaluation of reasonable deformation capacity of a building more exactly. An effective method based on the improved the adaptive lateral load distribution and the equivalent responses of a multistory building is proposed in this study to efficiently estimate the accurate inelastic seismic responses. The proposed method can be used to evaluate the seismic performance for the global inelastic behavior of a building and to accurately estimate its local inelastic seismic responses. In order to demonstrate the accuracy and validity of this method, inelastic seismic responses estimated by the proposed method are compared with those obtained from other analytical methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3423-3428
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• 2014

Numerical studies were performed to evaluate the structural safety of a greenhouse under both snow and wind loads. In the case of a wind load, fluid-structure interaction (FSI) method was used to consider the local pressure distributions on the greenhouse-induced by aerodynamic characteristics. The results showed that the maximum stress and deformation occur near the junction of pipe supports and rafters of the roof, where connecting clips are installed. Moreover, the wind load is a more severe condition than a snow load. Overall, these results will be used to design a prefabricated connecting clip with easy installation and low maintenance.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.143.2-143.2
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• 2005

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.480-485
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• 2017

The main reason for the heat induced accidents occurring at the after stern tube journal bearing is the excessive local pressure caused by the deflection of the propulsion shaft due to the propeller loads. It is expected that the contact area could beenlarged and the local pressure reduced accordingly by using a lining material having alow Young's modulus instead of the existing white metal. The purpose of this work is to investigate the characteristics of the pressure distribution and determine the allowable pressure value in the case where bearing products made of materials having a low Young's modulus are used. In this study, the propeller loads, heat effect, and hull deflection are considered in the evaluation of the local pressure of the ship propulsion shaft. Also, the Hertzian contact condition was applied. From the analysis results in the case where a lining material with a low Young's modulus was used, it was found that a robust design could be achieved and the local pressure could be reduced effectively independent of the load conditions. It will be possible to producenew products made of materials having a low Young's modulus if the manufacturer confirms the performance specifications drawn by this study.