• 제목/요약/키워드: interval finite element analysis

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간격 유한요소해석을 이용한 구조물의 위상 최적화 (Topology Optimization of Structures using Interval Finite Element Method)

  • 이동규;신수미;박성수
    • 한국전산구조공학회논문집
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    • 제19권4호
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    • pp.389-398
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    • 2006
  • 구조물의 최적 설계는 유한요소해석과 그것을 상용할 수 있는 컴퓨터 기술의 진보와 함께 발전해 오고 있다. 특히 위상 최적설계는 제한 조건들을 만족하는 구조물의 형상뿐만 아니라 최적 위상을 산출할 수 있다는 점에서 최근들어 많이 사용되고 있다. 일반적으로 유한요소해석은 영계수나 프와송 비와 같은 구조물의 재료특성 계수와 작용 하중 같은 변수들의 확정된 값을 가정하여 사용하나, 실제적으로 이러한 값들은 외부 환경의 영향이나 제조과정의 에러 등으로 인한 불확실성을 가진다. 따라서 정적 또는 동적인 구조응답 해석에서 다른 추이를 보일지도 모르며, 이는 구조물의 최적설계에도 영향을 미칠 수 있다. 본 논문에서는 구조물의 정적응답 해석에 대해 불확실성을 고려하는 간격 유한요소방법을 이용하여 구조물의 위상최적설계를 수행하고 그 해법을 제시하였다. 구조물의 최적설계 결과는 이전에 사용되었던 결과와 비교를 통하여 그 타당성을 입증하였다. 본 해석방법은 기존의 밀도분포법과 유한요소해석에 의한 위상설계와 비교하여 간단한 방법으로 서 선형 탄성 구조 응답의 불확실성을 고려하는 대체적인 구조물의 위상 최적결과를 예측할 수 있다.

An Interval Approach for Design and Analysis of Mechanical Systems with Uncertainties

  • Shin, Jae-Kyun;Li Chen;Jang, Woon-Geun
    • International Journal of Precision Engineering and Manufacturing
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    • 제3권4호
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    • pp.5-14
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    • 2002
  • This paper addresses the challenges of dealing with uncertainties based on interval analysis. An interval approach is proposed on the basis of Boundary Selection Method (BSM) for treating systems of linear interval equations in the presence of columnwise dependencies. An iterative procedure is developed for the problem solving where uncertainties are characterized in the form of interval quantities. An applied example is used to illustrate effectiveness and usefulness of the proposed approach. This new method can be applied for such circumstances that involve finite element analysis of structures, inverse dynamic analysis of mechanisms, and worst case design studies in the presence of the uncertainties.

A three-dimensional finite element analysis of two/multiple shots impacting on a metallic component

  • Hong, T.;Ooi, J.Y.;Shaw, B.A.
    • Structural Engineering and Mechanics
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    • 제29권6호
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    • pp.709-729
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    • 2008
  • This paper describes a three-dimensional dynamic finite element analysis of two/multiple shots impacting on a metallic component. The model is validated against a published numerical study. An extensive parametric study is conducted to investigate the effect of shot impacting with overlap on the resulting residual stress profile within the component, including time interval between shot impacts, separation distance between the impacting points, and impacting velocity of successive shots. Several meaningful conclusions can be drawn regarding the effect of shot impacting with overlap.

2차원 단면해석을 위한 정적-외연적 강소성 유한요소법의 개발 및 적용 (The Development of Static-explicit Rigid-plastic Finite Element Method and Application to 2-dimension Sectional Analysis)

  • 정동원;이승훈
    • 한국기계가공학회지
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    • 제2권2호
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    • pp.91-97
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    • 2003
  • In rigid-plastic finite element method, there is a heavy computation time and convergence problem. In this study, revised rigid-plastic finite element method Will be introduced. This method is the way that restrict the convergence interval. In result, convergence problem and computation time due to large non-linearity in the existing numerical analysis method were no longer a critical problem. It is expected that various results from the numerical analysis will give very useful information for the design of tools in sheet metal forming process.

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정적-외연적 강소성 유한요소법의 개발 및 펀치 행정구간에 따른 영향과 Osakada 방법의 초기 변형율 증분에 따른 영향분석 (Development of Static-explicit rigid-plastic finite Element Method and investigate the effect of punch stroke and the strain increment in Osakada method)

  • 정동원;이승훈
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1545-1548
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    • 2003
  • In rigid-plastic finite element method, there is a heavy computation time and convergence problem. In this study. static-explicit rigid-plastic finite element method will be introduced. This method is the way that restrict the convergence interval. In result, convergence problem and computation time due to large non-linearity in the existing numerical analysis method were no longer a critical problem. Also, we investigated the effect of punch stroke and the strain increment this method. It is expected that various results from the numerical analysis will give very useful information for the design of tools in sheet metal forming process.

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2차원 정적-외연적 강소성 유한요소법의 개발 및 펀치 행정구간에 따른 영향분석 (Development of 2-Dimensional Static-explicit Rigid-plastic Finite Element Method and Investigation of the Effect of Punch Stroke)

  • 정동원;이승훈
    • 한국기계가공학회지
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    • 제3권3호
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    • pp.39-45
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    • 2004
  • In rigid-plastic finite element method, there is a heavy computation time and convergence problem. In this study, static-explicit rigid-plastic finite element method will be introduced. This method is the way that restrict the convergence interval. In result, convergence problem and computation time due to large non-linearity in the existing numerical analysis method were no longer a critical problem. It is expected that various results from the numerical analysis will give very useful information for the design of tools in sheet metal forming process.

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고속 주축에서 클램핑력 및 회전수 변화에 따른 주축 인터페이스 접촉률 변화에 관한 연구 (A Study on the Contact Interval in the Main Spindle Interface of High Speed Spindle according to Variation of Clamping Force and Rotational Speed)

  • 황영국;조영덕;이춘만;정원지
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1749-1752
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    • 2005
  • High speed machining has become the main issue of metal cutting. Due to increase of the rotational speed of the spindle, problems, such as the run-out errors, reduced stiffness, must be overcome to improve the machining accuracy. In order to solve the problems, it is important to determine the appropriate clamping unit and tooling system. This paper presents an investigation into an evaluation of contact interval which is the interface between spindle taper hole and tool holder shank of the spindle. Finite element analysis is performed by using a commercial code ANSYS according to variation of clamping forces and rotational speeds. This paper proposed fit tolerance in order to evaluate the effects of clamping force and rotational speed on the contact interval in the spindle interface. From the finite element results, it has been shown that the rotational speed rather than clamping force mostly influence on the variation of the contact interval.

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고속 주축에서 클램핑력 및 회전수 변화에 따른 주축 인터페이스 접촉률 변화에 관한 연구 (1) (A Study on the Contact Interval in the Main Spindle Interface of High Speed Spindle according to Variation of Clamping Force and Rotational Speed (1))

  • 황영국;정원지;이춘만
    • 한국정밀공학회지
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    • 제23권3호
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    • pp.147-155
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    • 2006
  • High speed machining has become the main issue of metal rutting. Due to increase of the rotational speed of the spindle, problems, such as the run-out errors, reduced stiffness, must be overcome to improve the machining accuracy. In order to solve the problems, it is important to determine the appropriate clamping unit and tooling system. This paper presents an investigation into an evolution of contact interval which is the interface between spindle taper hole and tool holder shank of the spindle. Finite element analysis is performed by using a commercial code ANSYS according to variation of clamping forces and rotational speeds. This paper proposed fit tolerance in order to evaluate the effects of clamping force and rotational speed on the contact interval in the spindle interface. From the finite element results, it has been shown that the rotational speed rather than clamping force mostly influence on the variation of the contact interval.

Study of ground vibration induced by high-speed trains moving on multi-span bridges

  • Ju, S.H.
    • Structural Engineering and Mechanics
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    • 제59권2호
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    • pp.277-290
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    • 2016
  • This paper investigates the ground vibration induced by high-speed trains moving on multi-span continuous bridges. The dynamic impact factor of multi-span continuous bridges under trainloads was first determined in the parametric study, which shows that the dynamic impact factor will be large when the first bridge vertical natural frequency is equal to the trainload dominant frequencies, nV/D, where n is a positive integer, V is the train speed, and D is the train carriage interval. In addition, more continuous spans will produce smaller dynamic impact factors at this resonance condition. Based on the results of three-dimensional finite element analyses using the soil-structure interaction for realistic high-speed railway bridges, we suggest that the bridge span be set at 1.4 to 1.5 times the carriage interval for simply supported bridges. If not, the use of four or more-than-four-span continuous bridges is suggested to reduce the train-induced vibration. This study also indicates that the vibration in the train is major generated from the rail irregularities and that from the bridge deformation is not dominant.

알루미늄 합금재의 마찰교반용접 유한요소해석에 관한 연구 (A Study on the Finite Element Analysis in Friction Stir Welding of Al Alloy)

  • 이대열;박경도;강대민
    • 한국기계가공학회지
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    • 제14권5호
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    • pp.81-87
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    • 2015
  • In this paper, the finite element method was used for the flow and strength analysis of aluminum alloy under friction stir welding. The simulations were carried out using Sysweld s/w, and the modeling of the sheet was executed using Unigraphics NX6 s/w. The welding variables for the analysis were the shoulder diameter, rotating speed, and welding speed of the tool. Additionally, a three-way factorial design method was applied to confirm the effect of the welding variables on the flow and strength analysis with variance analysis. From these results, the rotating speed had the greatest influence on the maximum temperature, and the maximum temperature was $578.84{\pm}12.72$ at a confidence interval of 99%. The greater the rotating speed and shoulder diameter, the greater the difference between maximum and minimum temperature. Furthermore, the shoulder diameter had the largest influence on von Mises stress, and the von Mises stress was $184.54{\pm}12.62$ at a confidence interval of 99%. In addition to the increased shoulder diameter, welding speed, and rotating speed of the tool increased the von Mises stress.