• Computational Structural Engineering
• /
• v.10 no.3
• /
• pp.46-51
• /
• 1997

본 고에서는 3차원 전선구조해석에 사용하는 직접구조해석기법 및 준직접구조해석기법에 대하여 설명하고 실선계산을 통하여 두 기법의 차이를 비교하였다. 직접구조해석은 준직접구조해석에 비하여 방대한 시간 및 노력이 요구되기 때문에 전선구조해석의 목적으로 사용하기에는 추천할 기법은 아니나 준직접구조해석의 검증, 피로해석 및 신로도 해석 등 응력의 확률 기준이 필요한 경우에는 필수적으로 수행해야 할 것이다.

• The Korean Journal of Rheology
• /
• v.2 no.1
• /
• pp.27-32
• /
• 1990

본 연구에서는 전선피복 die 내고분자 물질의 이동현상에 관한여 Carreau model을 도입하여 유한요소법으로 수치해석을 수행하였다. Polyvinyl chloride(PVC)의 유변상수들의 변화가 유동에 미치는 영향을 조사하였고 온도에 따른 점도의 변화를 고려한 비등온 조건 및 전선피복 공정에서 발생할 수 있는 slip 경계조건을 적용시킨 경우에 대한 수치모사도 수행하였다.

• Fire Science and Engineering
• /
• v.16 no.3
• /
• pp.56-60
• /
• 2002

Recently, with the growth of software for electro-thermal analysis, it has been studied the precise analysis and investigation of cause for the electrical fire using computer simulation on the basis of theory for electro-thermal analysis. But it is very lacking for the precise analysis and investigation of cause for the electrical fire. In this paper, we have simulated the thermal analysis for electrical wire according to the value of current in a overload and a short with the electrical wire of the L's company product(600 V VVF) using the electro-thermal finite element method(Flux2D).

• Fire Science and Engineering
• /
• v.16 no.4
• /
• pp.72-76
• /
• 2002

Nowaday, with the growth of software for electro-thermal analysis, it has been studied the precise analysis and investigation of cause for the electrical fire using computer simulation on the basis of theory for electro-thermal analysis. But it is very lacking for the precise analysis and investigation of cause for the electrical fire. In this paper, we have simulated the thermal analysis for electrical wire according to the value of current and deteriorating time in a overload and a short with the electrical wire of the L's company product(600 V VVF : Three core) using the elec-tro-thermal finite element method(Flux2D).

• Journal of the Society of Naval Architects of Korea
• /
• v.44 no.3 s.153
• /
• pp.314-322
• /
• 2007

In general, the vibration and structural analyses have been carried out by using each finite element model separately because of different size of finite element mesh and different focusing area of each analysis. In some cases, however, it is required to perform both global vibration and structural analyses at the same time using a finite element model for global structural analysis, which asks for a special treatment for a vibration analysis. In this study, a technique to perform a global vibration analysis using a finite element model for a global structural analysis has been developed and its effectiveness has been verified by its application to a whole ship.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.11 no.6
• /
• pp.74-80
• /
• 1997

In this paper, we deal with the I -t characteristic of low voltage distribution fuse (line fuse). That fuse element has two parts;One is low temperature melting element(LTME) to put up with over current and the other is high temperature melting element (HTME) which put up with large current. Melting charateristic of fuse is determined by L TME and HTME. So we verified their properties of fuse design, mathematically, by simulating the thermal and electric characteristics of each other. We simulated the I-t characteristic of line fuse by using the numerical method;Finite Element Method(FEM). Then, we could acquire very similar result at the HTME and L TME area when compared the simlation result with experimental one.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.4 no.2
• /
• pp.82-90
• /
• 1993

전자파에 의한 산란현상의 해석은 지금까지 주로 시간조화함수의 형태를 지닌 전원에 의한 정 상상태의 산란에 관하여 이루어졌다. 그러나 레이다나 피파괴 검사, 전송선로 점검 등의 응용에서는 주로 펄스형태의 전자파를 사용하며, 따라서 시간에 따라 변화하는 함수형태의 전원에 의한 전자파의 산란해 석이 중요한 문제로 등장하였다. 또한 통신선로에서 외부의 잡음에 대한 혼신 등을 해석하거나, 낙뢰가 송 전선로에 미치는 영향을 해석하는 데에도 펄스신호의 산란해석이 필수적이다. 일반적인 함수의 형태를 지닌 전원에 의한 산란현상을 해석하기 위해서는 전원함수를 Fourier 변환하 여 주파수 영역의 스펙트럼을 구하고, 주파수영역에서의 산란해를 이용하여 Fourier 역변환을 하여 시간 영역의 해를 구할 수 있다. 주파수 영역에서의 산란판의 해를 Fourier 역변환 하기 위해서는 적분을 행하여야 하며, 일반적으로 적분과정에서 매우 복잡한 계산이 필요하고, 산란체의 구조가 복잡하여 해석 적인 해를 구할수 없는 경우에는 해석적으로 시간영역의 해를 구하는 것이 불가능하다. 시변 함수에 의 한 산란파를 구하기 위한 수치해석적 방법으로는 모멘트방법이나 유한요소법(Finite Element Method), 경계요소법(Boundary Element Method), 유한차분법(Finite Difference Method)등이 있으며, 해석적 해 를구할 수 없는 경우에 적용할 수 있는 반면에 많은 계산량이 요구된다.

• Journal of the Society of Naval Architects of Korea
• /
• v.49 no.4
• /
• pp.312-326
• /
• 2012

This paper considers a fully coupled 3D BEM-FEM analysis for the ship structural hydroelasticity problem in waves. Fluid flows and structural responses are analyzed by using a 3D Rankine panel method and a 3D finite element method, respectively. The two methods are fully coupled in the time domain using a fixed-point iteration scheme, and a relaxation scheme is applied for improve convergence. In order to validate the developed method, numerical tests are carried out for a barge model. The computed natural frequency, motion responses, and time histories of stress are compared with the results of the beam-based hydroelasticity program, WISH-FLEX, which was thoroughly validated in previous studies. This study extends to a real-ship application, particularly the springing analysis for a 6500 TEU containership. Based on this study, it is found that the present method provides reliable solutions to the ship hydroelasticity problems.

• Computational Structural Engineering
• /
• v.3 no.3
• /
• pp.133-140
• /
• 1990

Analysis of cable structures is complex because their force - displacement relationships are highly nonlinear and also because large deformations introduce geometric nonlinearity. Therefore, we must take account their geometric nonlinearity in the analysis and find the equilibrated shape of cable structures. In this paper, to slove these problems, numerical procedures involving geometrical nonlinearity are introduced. They are applicable to general cable net, flexible transmission lines and suspended cable roof. These procedures are divided into two parts; one is to obtain the equilibrated shapes and stresses of the cable structures with uniform load by flexibility iteration method, the other is to analyse the equilibrated structures subjected to nodal external forces by nonlinear finite element method.

• Journal of the Korean Society of Industry Convergence
• /
• v.7 no.1
• /
• pp.91-96
• /
• 2004

Overloading of electrical equipment results in excessive currents. As the heat developed in the cables is proportional to square of the current, they get overheated. The insulation on cables is generally made of materials which are damaged easily by excessive temperature. They may therefore lose their insulating properties and lead to short circuits. Since many insulating materials are combustible, they may even catch fire if the temperature rises to their ignition temperature. In this paper, we have simulated the thermal analysis for cable according to the value of current in a overload and a short with the cable of the L's company product(600 V, VV : Four Core) using the electro-thermal finite element method(Flux2D).