• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.2
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• pp.81-86
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• 2000

For on-shore structures, dynamic analysis becomes increasingly important as the water depth increases and the structural configuration becoines slenderer. In this study, an estimation method for equivalent three dimensional (30) hydrodynamic coefficients is introduced as a part of beam permutation technique development. The beam pemlUtation technique is being developed for obtaining an equivalent beam to a frame structure in order to reduce the degrees of freedom and thus the analysis time significantly. Two 3D structures are used in order to verify the obtained equivalent 3D hydrodynamic coefficients. Two commercial softwares, ANSYS and SACS, are used for the verification. The results of the present analysis are found to be satisfactory in comparison with those by the two softwares.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.2
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• pp.175-182
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• 2012

In this paper we are concerned with the performance of structural stability of torsion in square cross section of a beam with holes. The critical load is defined as the smallest load at which the equilibrium of the structure fails to be stable as the load is slowly increased from zero. The beams subjected to torsion are frequently encountered in general structures and these forces influence to the stability of structure. The boundary element method is found to be very efficient and accurate for the analysis of torsion problems including complex boundary conditions with respect to its simplicity and generality. In this paper, it is required to derive the boundary element formulation for torsion problem and integrate directly on the discrete boundary. To investigate the validity of the developed computer program, three distinctly solid cross-sections which are elliptical, rectangular and triangular one are analyzed, and comparisons are made with analytical approaches where these can also be used.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.79-88
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• 1997

Very stiff floor system in a residential-commercial building causes some problems in the numerical analysis procedure due to significant difference in stiffness with adjacent elements. Static analysis of structure with a stiff transfer-floor can be performed approximately in two steps for upper and lower parts for the structure. However, it is impossible to perform dynamic analysis in two steps with separate models. An efficient method for dynamic analysis of a structure with a right floor system is proposd in this study. The matrix condensation technique is employed to reduce the degree of freedom for upper and lower parts of the structure and a beam elements with rigid bodies at both ends are introduce to model the rigid floor system. Efficiency and accuracy of the proposed method are verified through analysis of several example structures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.32-37
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• 1991

최근 컴퓨터 및 제어 기술의 도움으로 기계 가공 분야에 있어 자동화, 정밀화, 그리고 무인화가 급속히 추진되고 있다. 이어 따라 대형화되고 복잡해지는 공작기계의 구조 해석과 정밀가공의 필요에 의해 동절삭 과정에 대한 관심이 더 한층 높아지게 되었다.(중략)

• Computational Structural Engineering
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• v.7 no.1
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• pp.91-98
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• 1994

Design sensitivity analysis method for the vibration of vehicle structure is developed using adjoint variable method. A variational approach with complex response method is used to derive sensitivity expression. To evaluate sensitivity, FEM analysis of ship deck and vehicle structure are performed using MSC/NASTRAN installed in the super computer CRAY2S, and sensitivity computation is performed by PC. The accuracy of sensitivity is verified by the results of finite difference method. When compared to structural analysis time on CRAY2S, sensitivity computation is remarkably economical. The sensitivity of vehicle frame can be used to reduce the vibration responses such as displacement and acceleration of vehicle.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.1
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• pp.61-67
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• 2011

This study is concerned with the shape optimization of structural members frequently found in critical area in a structure system, that is, highly stressed zone. Isogeometry analysis is well known to be the very efficient way to integrate the geometric modeling(CAD) and computational analysis(CAE). This can be accomplished by directly using the geometric modeling by NURBS(Non-Uniform Rational Basis Spline). In this study, an efficient computer code adopting the isogeometry concept has been developed for the structural analysis, in which CAD information can be directly used in the finite element modeling. In order to show the validity of the present code, the present results are compared with those by using the commercial package, that is, MSC/NASTRAN. The present isogeometric analysis procedure has been integrated with the optimization procedure to deal with the optimization problem found in the context of structural mechanics. The present system has been successfully applied to the shape optimization of cantilever structure having bracket. From the present study, it can be seen the validity of the present approach and computer codes developed in this study. This paper ends with some discussions about the practical usefulness of the present approach which is based on isogeometry analysis, and extension of the present study.

• Journal of the KSME
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• v.30 no.S1
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• pp.45-55
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• 1990

과거 대형컴퓨터와 중형컴퓨터에서만 가능하던 유한요소법을 이용한 CAE기술들이 마이크로컴퓨 터의 발달에 따라 개인용 컴퓨터에서도 가능하게 되었다. 여기서는 사출제품 설계 및 금형설계에 있어 필수적인 설계도구로 사용되는 CAE프로그램중 구조 해석용 프로그램인 Micro-STANS와 사출공정 해석용 프로그램인 C-FLOW가 마이크로컴퓨터 상에서 이용 가능함을 설명하였다. 이러 한 CAE 소프트웨어들은 비용과 노력이 많이 소모되는 시제품제작이 없이도 사출공정에 대한 정 보와 제품강도에 대한 정보를 얻을 수 있게 함으로써 초기설계단계에서 제품의 설계평가가 가능 하게 하였다. 보다 높은 생산성, 보다 낳은 설계 납기단축, 비용절감을 도모해야 하는 사출제품 설계자들에게 초기단계에서 제품의 설계 및 가공에 대한 문제점을 미리 파악할 수 있게 함으로써 대단히 강력한 설계 도구로 이용될 수 있을 것이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2015-2022
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• 2012

This paper is about the analysis and design of avionics equipment's housing and PCB(Printed Circuit Board) such as air data computer. Avionics equipment's structural design as well as electrical properties is very critical and should be proved from design phase by analysis method. First, analyze the static load and vibration requirement for the installed equipment, and then proved it satisfy with its requirement using the computational structural analysis. Commercial tools were used for computation and the rib design of housing was verified and the placement of electrical component was proposed using the PCB's local displacement information.

• Journal of the Korea Convergence Society
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• v.10 no.9
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• pp.173-177
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• 2019

This study is door safety device for the structural analysis are described. Recently emerged as a key point of the door safety and increase the need of a door safety device. In order to improvement this inconvenience, the door safety device was design and structural analysis by using CATIA. CATIA utilizes door safety device element model for displacement, stress and strain energy were obtained. Consideration of door open angles were $95^{\circ}$, $100^{\circ}$, $105^{\circ}$, $110^{\circ}$, $115^{\circ}$, $120^{\circ}$. These results will be provided to develop new concepts of door safety device as initial data.

• Computational Structural Engineering
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• v.5 no.1
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• pp.11-14
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• 1992

최근 교량공학자들의 공통관심사는 초대형 구조물을 가설하고, 적절한 유지관리에 의해 기존 구조물의 공용수명을 연장시키는 것 등을 들 수 있다. 고성능 컴퓨터 산업의 발달로 인한 구조해석의 정밀화, 경량골재 및 고강도 재료의 개발, 용접성과 시공법의 발달 및 초대형 크레인과 같은 건설기자재의 개발 등으로 인하여 초대형 구조물의 가설은 외국에서 뿐만 아니라 국내에서도 가능하게 되었다. 그리고 구조물의 공용수명을 연장하기 위해서 최근에는 첨단계측장비와 신호처리기술, 신뢰성이론, 피로파괴이론 및 system identification technique 등의 발달로 인해 비교적 정확하게 교량구조물의 손상부위와 손상정도의 파악이 가능하게 되었다. 그리하여 가까운 시일내에 100년 이상의 공용수명을 갖는 초대형 교량이 출현될 것으로 전망된다. 따라서 교량 공학자들은 앞으로 장대교량의 설계와 시공 및 유지관리의 완전 국산화를 위한 연구에 더욱 박차를 가해야 할 것이다.