3차원 수치해석에 의한 필 댐의 누수량 평가

최병일(Byoungil Choi) 한국지반환경공학회 2015 한국지반환경공학회논문집 Vol.16 No.8

침투에 대한 안정성 평가 시 댐체의 가장 큰 단면을 반영해 2차원으로 수치해석을 실시하는 것이 일반적이며, 해석결과를 이용한 침투수량 평가 시 댐체 하부지반을 단순한 직사각형 형태로 가정하여 침투수량을 구한 후 단면형상을 반영해 최종 침투수량을 계산하고 있다. 하지만 최근 기술의 발달로 댐 시공 시 다양한 형태의 지반 위에 다양한 형태의 댐들이 축조되고 있는 점을 감안하면 3차원 수치해석을 통해 댐체의 형상 및 지형조건을 보다 정확하게 반영한 결과를 이용하여 결론을 도출하는 것이 바람직하다고 판단된다. 따라서 본 연구에서는 3차원 FEM 수치해석법을 이용하여 강우량을 포함한 다른 기타요인은 배제한 후 댐체로만 통과되는 침투수량 평가를 통해 안전관리를 할 수 있는 방안을 제시하고자 한다. Using 2D numerical analysis that covers the largest section of the dam body, a process is generally performed when evaluating its stability against seepage. The quantity of seepage is first obtained by assuming that its bottom topography is in the simple form of a rectangle, it is then calculated by reflecting its sectional shape during this process of analyzing the seepage quantity. Considering that various forms of dams are being constructed on various types of ground, thanks to more recent technological advances, it is judged more appropriate to draw a conclusion by means of the results on reflecting the realistic shape and topographical conditions of the dam body through 3D numerical analysis. Therefore, this study intends to present a method designed to carry out safety management by evaluating the correct quantity of water leakage that passes only through the dam body, having excluded other factors that include the amount of rainfall through the 3D FEM analysis.

하나로 조사시험용 다공 원통헝 구조물의 온도해석

최영진,강영환,이영신,Choi Young-Jin,Kang Young-Hwan,Lee Young-Shin 한국전산구조공학회 2004 한국전산구조공학회논문집 Vol.17 No.4

재료나 핵연료조사시험에서 다공원통형구조물의 모든 구성품에서 감마열 및 fission과 같은 열원이 발생한다. 본 연구는 조사시험중 다공원통형구조물의 열적건전성을 평가하기 위해 온도분포에 대한 일반해를 구하는데 그 목적이 있다. 다공원통형 구조물의 온도해석을 위해 2차원 열전토 방정식을 이용하였다. 유한요소해석은 ANSYS 6.1을 이용하여 수행하였다. 다공원통형 구조물의 온도해석에서 이론해석결과와 유한요소해석결과는 홀의 개수가 3개 이하에서는 온도가 서로 잘 일치하는 것으로 나타났다. 구조물의 홀 개수가 4개일때, 온도분포해석에 대한 두 결과의 차이가 증가하였다. During the irradiation tests of material and fuel rod, all components of the cylindrical structure with multiple holes act like heat sources due to high gamma heat and fission heat. The objective of this study is to formulate the general solution for the temperature distribution to estimate the thermal integrity of structure during irradiation tests. For the temperature distribution analysis, the two-dimensional heat conduction theory is used. The unmerical analysis is performed by the commercial finite element analysis code, ANSYS 6.1. If the cylindrical structure with hole number would not exceed three holes, the analysis results and finite element results are good agreement together. For the structure with four holes, the discrepancy between FE results and analysis results of the structural temperature distribution is increased.

선박용 파이프 루프 곡선부의 구조해석에 관한 연구

박치모(Chi-Mo Park),배병일(Byoung-Il Bae) 한국해양공학회 2010 韓國海洋工學會誌 Vol.24 No.5

Many pipes that are arranged longitudinally in ships have loops at intervals to prevent the failure of the pipes as they absorb large portions of the axial load caused by the bending if the hull girder and/or thermal loads when the pipes are carrying very hot fluids. Since the loops are curved at corners, an efficient method for conducting the structural analyses of these curved portions is required. In this paper, a pipe loop was analyzed by an analytical method and by the finite-element method in four different ways, i.e., based on straight-beam elements, curved-beam elements, 2-D shell elements, and 3-D solid elements. The results if the five analyses were compared to check the validity of the current curved-beam theory. The paper includes some suggestions on how to analyze the pipe loops efficiently.

축 방향 누설 자속이 고려된 2차원 FEA를 활용한 표면 부착형 영구자석 동기 전동기의 설계

정재우(Jaewoo Jung),박형일(Hyungil Park),윤재섭(Jaeseop Yoon),정하민(Hamin Jung),여훈(Hoon Yeo),홍정표(Jungpyo Hong) 한국자동차공학회 2017 한국자동차공학회 부문종합 학술대회 Vol.2017 No.5

This paper deals with optimum design of surface mounted permanent magnet synchronous motor (SPMSM) for automotive component. For a compact system structure, it was designed as a motor with a 14-pole 12-slot concentrated winding and hollow shaft. The motor is a thin type structure which stator outer diameter is relatively large compared to its axial length and is designed to have a high magnetic saturation for increasing the torque density. Since the high magnetic saturation in the stator core increases the axial leakage flux, a 3-dimensional (3-D) finite element analysis (FEA) is indispensable for torque analysis. However, optimum designs using 3-D FEA is inefficient in terms of time and cost. Therefore, equivalent 2-D FEA which is able to consider axial leakage flux is applied to the optimization to overcome the disadvantages of 3-D FEA. The structure for cost reduction is proposed and optimum design using equivalent 2-D FEA has been performed.

선박 해양구조물 파이프 곡선부의 굽힘 응력 해석

박치모(Chi-Mo Park),배병일(Byoung-Il Bae) 대한조선학회 2011 대한조선학회 학술대회자료집 Vol.2011 No.6

Most ships and offshore structures are equipped with variety of pipes which inevitably contain curved portions. While it has been a usual practice to conduct the bending stress analysis of those curved pipes using the straight beam theory, this paper adopted four different types of finite elements; straight-beam, curved-beam, two-dimensional shell and three-dimensional solid elements, for the finite element analysis of a curved pipe and compared the analysis results to draw a conclusion that both two-dimensional shell and three-dimensional solid elements equally give reasonable results while both beam elements yield too low stress values. The paper ends with a practical suggestion on how to efficiently estimate the maximum bending stress in a curved pipe.

다양한 기하학적 인자를 고려한 고무받침의 압축 및 전단 내력

박지용,김주우,정희영,Park, Ji Yong,Kim, Joo Woo,Jung, Hie Young 한국강구조학회 2014 韓國鋼構造學會 論文集 Vol.26 No.6

본 논문에서는 적층탄성받침과 납 고무받침을 대상으로 재료 및 기하비선형을 고려한 3차원 유한요소로 모델링하고 다양한 파라미터에 대한 압축 및 전단특성을 비교 분석하여 적층고무받침의 해석적 데이터베이스를 구축하였다. 유한요소해석에서 적층고무받침을 모델링하기 위해서 고무시편시험을 통해 고무의 응력-변형률 관계를 얻어내고 커브피팅을 이용하여 고무재료상수를 구하였다. 고무재료상수를 검증하기 위하여 실제 적층탄성받침 제품 시험과 유한요소해석을 비교함으로서 고무재료상수의 유효성을 확인하였다. 적층탄성받침과 납고무받침의 압축거동은 1차 형상계수에 따라서 가장 큰 영향을 받았으며, 전단거동은 2차 형상계수에 따라 크게 달라지는 것을 알 수 있었다. 또한 납의 직경이 증가할수록 납 고무받침의 수평강성과 에너지 소산능력이 증가하였다. In this study, compression and shear characteristics of laminated rubber bearings and lead rubber bearings with various parameters are investigated by using material and geometric nonlinear three-dimensional finite element analysis. Rubber coupon tests are performed to make a model of the laminated rubber bearings. In addition, the material constants of the rubber are calculated by the curve fitting process of stress-strain relationship. The finite element analysis and experimental tests of the laminate rubber bearings are used to verify the validity of the rubber material constants. It is seen that the compression behavior of the laminated rubber bearings and lead rubber bearings mainly varies depending on the first shape factors and their shear behavior significantly varies depending on the second shape factors. In addition, the horizontal stiffness and energy dissipation capacity of lead rubber bearing are increased when the diameter of a lead bar is increased.

클래드 판재성형 공정의 2D 시뮬레이션

전만수(M. S. Joun),이장호(J. H. Lee),김민철(M. C. Kim),황지훈(J. H. Hwang),심재원(J. W. Sim),홍석무(S. M. Hong) 한국소성가공학회 2014 한국소성가공학회 학술대회 논문집 Vol.2014 No.10

In this paper, a two-dimensional finite element analysis model for rectangular clad plate drawing is proposed to examine its detailed plastic deformation. Three-dimensional behaviors of plastic deformation of clad plate are investigated using some finite element predictions and finite element predictions of its drawing process are qualitatively compared with the experiments. Based on the observations, a two-dimensional analysis model is proposed, which reveals that relatively thin clad material has little influence on history dependent variables including strain and damage. However, residual stress tends to concentrate very much on the clad material.

강재 리브가 설치된 분절 프리캐스트 콘크리트 아치 시스템의 2차원 해석 방법에 관한 연구

권태윤 ( Kwon Tae-yun ),허정원 ( Huh Jungwon ),이원홍 ( Lee Won-hong ),안진희 ( Ahn Jin-hee ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.25 No.2

강재 리브가 설치된 분절 프리캐스트 콘크리트 아치 시스템은 프리캐스트 콘크리트 패널 외부에 설치되는 강재 리브를 활용하여 상대적으로 두께가 얇은 프리캐스트 콘크리트 패널로 분절되어 아치를 구성하도록 제안되었다. 제안된 지중아치 시스템은 3차원 유한요소 해석 방법이 적용되어 요소의 개수가 많고 각 시공단계를 고려함에 따라 많은 해석 시간이 소요되므로 동적 거동 평가와 다양한 지반 변수 및 부재 최적화 등을 위한 해석 방법으로 합리적이지 않을 수 있다. 따라서, 본 연구에서는 제안된 지중아치 시스템의 동해석 및 부재 최적화 등 다양한 조건을 평가할 수 있는 2차원 해석 방법을 검토하였다.

H-pile 토류벽의 수평변위와 굴착 폭에 관한 해석적 연구

박춘식(Park, Choon-Sik),정성민(Joung, Sung-min) 대한토목학회 2020 대한토목학회 학술대회 Vol.2020 No.10

2차원 절삭에서 FEM 해석의 유효성에 관한 연구

윤재웅,김홍석,Youn, Jae-Woong,Kim, Hong-Seok 한국생산제조학회 2010 한국생산제조학회지 Vol.25 No.3

In general, the direct experimental approach to study machining processes is expensive and time consuming, especially when a wide range of parameters are included: tool, geometry, materials, cutting conditions, etc. The aim of this study is to verify the effectiveness of finite element method for orthogonal cutting process by comparing the simulated cutting forces with measured results. Two commercialized finite element codes $AdvantEdge^{TM}$ and Deform-$2D^{TM}$ have been used to simulate the cutting forces in orthogonal cutting process. In this paper, estimated cutting and feed force components are compared with experimental results for different two materials. As a result, it has been found that FEM simulation is effective for understanding and predicting the orthogonal cutting process although some improvements on friction model and remeshing process are needed.