• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.2
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• pp.171-184
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• 1999

이 논문은 시공단계를 고려한 콘크리트 프레임 구조물의 거동 해석을 다루고 있다. 고층건물의 경우 하루에 시공이 완료되지 않으므로 각 시공단계에 따라 콘크리트의 시간의존적 현상은 다르게 발생된다. 이를 위하여 이 논문에서는 일반적인 프레임 해석기법에 콘크리트의 시간의존적 특성을 고려하였다. 이 연구에 도입된 해석기법은 단면을 가상의 층으로 나누고 각층은 일축상태로 가정한 적층단면을 사용하였다. 요소는 평면 보요소를 사용하였으며 강성행렬은 변위법을 바탕으로 유도하였고 전체적인 구조해석은 비선형 구조해석 방법의 하나인 복합법을 사용하였다. 콘크리트의 시간의존적 특성을 고려하기 위하여 단면의 각 층에서 크리프와 건조수축에 의한 변형률을 계산하였으며 크리프는 크리프 Compliance의 전개에 기본을 둔 1차 순환적 단계 알고리즘을 사용하였다. 끝으로 이 연구에서 제안된 해석모델을 이용하여 프레임해석 및 기둥축소에 관한 예제를 해석하였다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.4
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• pp.307-316
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• 2002

In order to evaluate the deformation and stiffness of frame structure for fishery, composed of unit platforms which made of two concentric high density polyethylene buoys fixed by clamps and belts and rubber hinge components, under wave, the structural analysis for the square type of the structure was carried out by using finite element methods. The accurate physical properties of rubber hinge components determined by material tests were an important parameter to evaluate more reliable structural stability for the structure. The idealization to beam element with equivalent stiffness and rubber element with linearity for rubber hinges was necessary for the modeling of rubber component which has hyper-elastic characteristics. In addition, it was shown that the structural response of the structure under wave was larger in the hogging condition than that of in the still water or in the sagging condition.

• Journal of Aerospace System Engineering
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• v.18 no.4
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• pp.61-69
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• 2024

With increasing interest in aviation leisure sports, the demand for ultralight aircraft has increased, highlighting the necessity for robust structural design of the aircraft. In response, this study conducted static structural analysis and free-fall analysis of fuselage frame of ultralight aircraft. Robust design and crashworthiness under operational load conditions and vertical impact scenarios were evaluated by assessing maximum stress and safety factors. Analyses were performed using finite element method-based software ANSYS Workbench. Results including stress distribution and strain were analyzed to verify the safety of the designed fuselage frame. Additionally, this study predicted excessive deformation and failure locations of the fuselage frame during vertical drop impacts.

• Computational Structural Engineering
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• v.9 no.2
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• pp.16-22
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• 1996

스페이스 프레임의 설계과정에서 컴퓨터의 급진적인 진보와 많은 연구노력의 결과로 전체 설계과정이 통합자동화 방향으로 진행되고 있으며, 특히 구조해석과 구조설계분야에서 중요한 진보가 이루어져 왔다. 본문에서는 스페이스 프레임의 설계과정을 시스템화함에 있어서 자동화 방법론의 개괄적인 내용과 스페이스 프레임의 3차원적인 복잡한 형태를 표현하기 위한 Formex 대수학 (FORMEX ALGEBRA)의 적용사례에 대한 설명 및 후처리단계에서 해석결과치를 가지고 코드검토에 대한 규준식의 소개와 프로그램에 대한 내용을 설명한다.

• Journal of Korean Society of Steel Construction
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• v.28 no.6
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• pp.395-402
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• 2016

Space frame structures considering the components such as forms, layers, grids, etc. are possible to form a large space without interior columns. Here, steels having the yield strengths of 210 MPa to 450 MPa are generally used. The high strength steel (i.e., yield strength of 690 MPa) having suitable weldability, aseismicity and economics have been recently developed. In this paper, the high strength steel is applied to the space frame structures in order to analytically find out their transient responses considering the material and geometric nonlinearities. For various circular dome types of space frame structures, the modal analysis and nonlinear transient analysis are carried out using nonlinear three dimensional finite element analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.1-8
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• 2016

In this paper, we perform structural analysis for a base frame which is used to support a motor for large centrifugal compressor drives and a safety assessment according to the concrete placement. First, the structural analysis about four loading conditions for the motor base frame was conducted and the structural safety was evaluated through both the maximum distortion energy theory and Mohr-Coulomb theory. It was possible to perform a more reasonable safety evaluation against local stresses occurring at the discontinuous portion of the fragile structural members by applying the safety assessment through ASME VIII Div. 2. In addition, the motor base frames with and without the internal concrete placement were quantitatively compared by the structural analysis and safety evaluation using ASME code and it was found to improve the structural integrity due to the concrete placement.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.3
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• pp.191-198
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• 2013

In this paper, the effects of uncertain material constant on the nonlinear behavior of steel frames with semi-rigid joints are examined. As to the probabilistic model, a normal distribution is assumed to simulate the uncertain elastic modulus of steel material. A nonlinear structural analysis program, which can consider both semi-rigidity in joints of the steel frames and uncertainty in the material constant, is developed. Including the geometric, material and connection nonlinearites which are the parameters of nonlinear behavior of steel frames, probabilistic analysis is conducted based on the Monte-Carlo simulation. In the probabilistic analyses, we consider the three different cases for random variables. The deterministic analysis results are shown to be in good agreement with those of the previous research results in the literature. As to the probabilistic analyses, it is observed that the coefficient of variation(COV) of displacements increases as the loading increases, and that the values of COV are dependent on the structural features of the frames.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.31-32
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• 2006

본 논문은 중형엔진 조립과정에서 실린더 프레임 회전 작업에 사용하는 지그의 구조해석을 수행한 후, 지그의 안전성을 검토하고 지그의 경량화를 통하여 실용적인 지그 설계안을 제안하였다. 현장 작업자가 들 수 있는 최대 무게를 넘는 지그를 구조해석 모델로 선정한 후, 해석모델은 지그, 실린더 프레임, 볼트, 너트, 샤클 핀을 3차원 입체요소로 구성하고 ABAQUS/Standard를 사용하여 재료 비선형 및 접촉을 고려한 구조해석을 수행하였다. 구조최적화를 위하여 응력이 상대적으로 낮은 부위와 작업성을 고려하여 설계변수를 선정하고, 실험계획법의 직교배열표를 활용하여 설계변수에 대한 각 부위의 민감도와 경량화 모델을 도출하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.10a
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• pp.116-122
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• 1995

본 논문에서는 컴프레서 쉘의 구조해석을 수행하기 위하여, 범용 구조 해석 패키지인 MSC/NASTRAN을 이용하여 컴프레서 쉘 전체의 동특성 해석을 수행하였으며, MSC/NASTRAN의 Superelement 모듈인 부분구조합성법을 이용하여 구조물 전체의 동특성해석을 수행하였다. 그리고, 각 분계의 변형 및 운동 에너지를 산출하여 전체 구조물의 고유모드에 대한 분계의 기여도를 평가하였으며, 각각의 에너지에 기여가 높은 분계의 형상을 변경하여 구조물 전체가 원하는 동특성을 얻도록 하였다.

• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.69-75
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• 2015

This research focuses on structural stability of the multi-aerial platform. In this study, we conduct structural analysis for the lower structures such as sub frame, out-trigger and chassis frame, by using a universal structural analysis program NASTRAN based on 3D CAD data, material properties, load conditions and boundary conditions. We confirm the position of local stress exceeding the yield strength, through structural analysis of 4 cases for load conditions. As the results, it is possible to relax stress concentration in a way such as changing the thickness, reinforcing the material of the lower frames.