• 대한기계학회논문집A
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• 제26권4호
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• pp.644-652
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• 2002

Increasing demands for Electric Resistance Welded pipes of high quality with thick wall require c lose investigations in edge deformation by slitting, strip deformation during break down farming, and difference of circumferential length. In order to obtain good quality of a welding zone, it is necessary to predict the edge shape of the initial strip. The modeling of the multi-pass thick tube roll forming process with rigid plastic finite element method ultra the edge shape prediction of an initial strip with 2nd-degree polynomial regression method are presented. Edge shapes of initial strip have been analyzed by the finite element method and designed by the regression method to satisfy the requirements in target fin pass. It is concluded that the proposed edge design method results in optimal edge shapes sat string the design requirements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.1117-1119
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• 1999

An edge finite element method is applied to calculate the field distribution of a coupled waveguide structure. We compares a node based finite element method with the edge element one. For 2-d eigenvalue problems of waveguide structures, the former generates spurious eigenmodes, but the latter dose not. Using an simple rectangular waveguide, we implement both methods to obtain some results of field computation in waveguide. The paper shows that the finite element method using edge elements succeeds in suppressing spurious solutions.

• Structural Engineering and Mechanics
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• 제62권1호
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• pp.11-20
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• 2017

The base force element method (BFEM) is a new finite element method. In this paper, a degenerated 4-mid-node plane element from concave polygonal element of BFEM was proposed. The performance of this quadrilateral element with 4 mid-edge nodes in the BFEM on complementary energy principle is studied. Four examples of linear elastic analysis for plane frame structure are presented. The influence of aspect ratio of the element is analyzed. The feasibility of the 4 mid-edge node element model of BFEM on complementary energy principles researched for plane frame problems. The results using the BFEM are compared with corresponding analytical solutions and those obtained from the standard displacement finite element method. It is revealed that the BFEM has better performance compared to the displacement model in the case of large aspect ratio.

• 전기학회논문지
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• 제57권12호
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• pp.2194-2198
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• 2008

In this paper, the construction of secondary reaction plate is analyzed by 3-D Finite Element Method(3-D FEM) to consider the influence of its variation on the transverse edge effect of LIM. The effective 3-D analysis model for considering the transverse edge effect caused by the finite widths of the primary and the secondary is proposed. The simple method measuring the transverse edge effect by using the patterns of currents induced in the secondary reaction plate is also proposed. With this effective analysis method, various models of secondary reaction plate with overhang and cap has been analyzed to consider the relationship between the construction of secondary reaction plate and the transverse edge effect of LIM.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.954-957
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• 2004

Tire belt durability is characterized by the initiation of a crack at the belt edge region, and the propagation of the crack until the ply is separated. Experimental methods have been used to analysis of the belt durability in the cord-reinforced rubber composite tires, but it takes much cost and time to make experiments. In this paper, a finite element method to analyze the fatigue life of a crack at the belt edge of tires is presented. The fatigue life is analyzed by using a three-dimensional Finite Element Modeling. This method includes a global-local finite element analysis to provide the detail necessary to model explicitly an internal crack and use of the J-integral for energy release rate evaluation.

• Journal of electromagnetic engineering and science
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• 제18권3호
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• pp.175-181
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• 2018

The array patterns of a patch array antenna were calculated using an active element pattern (AEP) method that considers ground edge effects. The classical equivalent radiation model of the patch antenna, which is characterized by two radiating slots, was adopted, and the AEPs that include mutual coupling were precisely calculated using full-wave simulated S-parameters. To improve the accuracy of the calculation, the edge diffraction of a ground plane was incorporated into AEP using the uniform geometrical theory of diffraction. The array patterns were then calculated on the basis of the computed AEPs. The array patterns obtained through the conventional AEP approach and the AEP method that takes ground edge effects into account were compared with the findings derived through full-wave simulations conducted using a High Frequency Structure Simulator (HFSS) and FEKO software. Results showed that the array patterns calculated using the proposed AEP method are more accurate than those derived using the conventional AEP technique, especially under a small number of array elements or under increased steering angles.

• 대한기계학회논문집A
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• 제32권1호
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• pp.54-62
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• 2008

In this paper the fretting wear of press-fitted specimens subjected to a cyclic bending load was simulated using finite element analysis and numerical method. The amount of microslip and contact variable at press-fitted and bending load condition in a press-fitted shaft was analysed by applying finite element method. With the finite element analysis result, a numerical approach was applied to predict fretting wear based on modified Archard's equation and updating the change of contact pressure caused by local wear with influence function method. The predicted wear profiles of press-fitted specimens at the contact edge were compared with the experimental results obtained by rotating bending fatigue tests. It is shown that the depth of fretting wear by repeated slip between shaft and boss reaches the maximum value at the contact edge. The initial surface profile is continuously changed by the wear at the contact edge, and then the corresponding contact variables are redistributed. The work establishes a basis for numerical simulation of fretting wear on press fits.

• 융합정보논문지
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• 제11권2호
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• pp.41-46
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• 2021

그레이스케일 수학적 형태학에 기초한 에지 검출 알고리즘의 방법은 영상 노이즈를 제거와 병렬처리 가능하고 연산속도가 빠르다는 장점을 갖고 있다. 그러나 단일 구조적 스케일 요소를 사용하여 영상의 에지 검출을 하는 방법은 영상정보에 따라서 영향을 받을 수 있다. 그레이스케일 형태학의 특성은 구조적원소를 반복하여 확장, 침식, 열림, 담힘 연산을 함으로써 연산 결과 에지정보 결과에 제한적일 수 있다. 본 논문에서 잡음에 강인한 방향성을 갖는 구조적원소를 적용한 후 원소내의 각 픽셀 정보에 가중치 엔트로피를 적용하는 에지 검출 알고리즘을 제안한다. 영상에 적용하는 멀티 스케일 구조적 요소를 적용한 결과와 방향성 가중치 엔트로피를 적용한 연산결과를 비교분석하였으며, 시뮬레이션 결과는 제안된 알고리즘이 에지 검출에서 우수함을 보였다.

• 반도체디스플레이기술학회지
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• 제9권3호
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• pp.35-39
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• 2010

Interfacial stress singularity induced in an analysis model consisting of the polymeric thin film and the elastic substrate has been investigated using the boundary element method. The interfacial singular stresses between the viscoelastic thin film and the elastic substrate subjected to a uniform moisture ingression are investigated for the case of a small interfacial edge crack. It is assumed that moisture effects are assumed to be analogous to thermal effects. Then, the overall stress intensity factor for the case of a small interfacial edge crack is computed. The numerical procedure does not permit calculation of the limiting case for which the edge crack length vanishes.

• 소성∙가공
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• 제13권6호
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• pp.484-489
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• 2004

This paper employed a systematic analysis using a 2-D hybrid special finite element containing an edge crack in order to describe the fracture behavior of spot-welds in automotive structures. The 2-D hybrid special finite element is derived form a mixed formulation with a complex potential function with the description of the singularity of a stress field. The hybrid special finite element containing an edge crack can give a better description of its singularity with only one hybrid element surrounding one crack. The advantage of this special element is that it can greatly simplify the numerical modeling of the spot welds. Some numerical examples demonstrate the validity and versatility of the present analysis method. The lap-shear, lap-tension and angle-clip specimens are analyzed and some useful fracture parameters such as the stress intensity factor and the initial direction of crack growth are obtained simultaneously.