• Title/Summary/Keyword: FEM program

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Prediction of Cutting Stress by 2D and 3D-FEM Analysis and Its Accuracy (2D-3D FEM 해석에 의한 절단응력의 해석 및 정도)

  • 장경호;이상형;이진형
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.95-101
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    • 2001
  • Steel bridges, which have been damaged by load and corrosion, need repair or strengthening. In general, before the repair welding procedure, cutting procedure carry out. Therefore, the investigating of the behavior of stress generated by cutting is so important for safety of structure. Residual stress produced by gas cutting was analyzed using 2D and 3D thermal elasto-plastic FEM. According to the results, the magnitude of temperature was analyzed by 2D-FEM is smaller than that was analyzed using the 3D-FEM program at the start and end edge of flange. And the magnitude and distribution of residual stress of perpendicular to the cutting line was analyzed by the 2D-FEM program was similar to that was analyzed by the 3B-FEM program. Therefore, it is possible to predict of cutting stress by 2D and 3D FEM.

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An Object-oriented Finite Element Analysis Program Architecture of Easy Extension (확장이 쉬운 구조의 객체지향 유한요소해석 프로그램)

  • Nam, Yong-Yun
    • 연구논문집
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    • s.33
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    • pp.27-38
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    • 2003
  • The object-oriented programming languages are widely used in the modern software engineering. The procedural type FEM codes are still used because it is very hard and cost consuming job to re-code them into object-oriented programs. In this study, a FEM program was newly designed and coded with C++, an object-oriented language. Also a special programming technique, auto-loading technique was developed for open structured program, with which the extension and maintenance can be carried out easily. For example, the additions of element libraries to an existence FEM program do not require any modifications of the program.

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Development and application of FEM/GEM program for evaluating formability of stamping dies (스탬핑 금형의 성형성 평가를 위한 유한요소/기하학힘평형법 프로그램 개발과 응용)

  • Kim, J.P.;Keum, Y.T.
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.3
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    • pp.80-93
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    • 1996
  • A 2-dimensional FEM/GEM program was developed under the plane strain assumption using linear line elements for analyzing stretch/draw forming operations of an arbitrarily shaped draw-die. FEM formulation adopted a new algorithm for solving force equilibrium as well as non-penetration condition simultaneously. Also, a rigid-viscoplastic material model with Hill's normal anisotropic yield condition and rate-sensitive hardening law is assumed, along with the Coulomb friction law in the contact regions. For the case of numerical divergence at nearly final forming stages, geometric force equilibrium method(GEM) is also introduced. The developed program was tested by simulating the forming processes of cylindrical punch/open die, and the drawing processes of automotive oilpan and hood inner panel in order to verify the usefulness and validity of FEM/GEM formulation. The numerical simulation verified the validity and robustness of developed program.

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A Study on the Optimum Design Using FEM and ADS (FEM과 ADS를 이용한 최적설계에 관한 연구)

  • Kim, M.J.;Lee, S.S.;Park, J.H.;Kim, S.M.;Jeon, E.C.
    • Proceedings of the KSME Conference
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    • 2001.06c
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    • pp.146-151
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    • 2001
  • This study is an investigation for the ADS optimum design by using FEM. We write out program which express ADS perfectly and reduce the required time for correcting of model to the minimum in solution and manufacture result. We complete algorithm which can plan optimum forming of model by feedback error information in CAE. For that, we draw up ADS program which modeling rachet wheel by using visual LISP and telegraph to ANSYS, structural solution program, we can solve stress solution. Then we correct model by feedback date obtaining in solution process, repeat course following stress solution again and do modeling rachet wheel for optimum forming. That is our aim. As a result of experience, we can develope automatic design program using Visual LISP and exhibit ADS as modeling third dimension CAD for optimum design. Also, we develop optimum design algorithm using ADS and FEM. In rachet wheel, greatest equivalence stress originates in key groove comer and KS standard is proved the design for security.

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Development of Seismic Analysis Technique for Masonry Structure (조적식 교각의 내진해석 기법 개발)

  • 정용철;배준현;이준석;강영종
    • Proceedings of the KSR Conference
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    • 2002.05a
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    • pp.171-176
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    • 2002
  • There are many railway structures which were designed without conidering aseismic capacity. In special, masonry structures constructed long time ago should be reviewed about their resistance to earthquake. In this paper, technique to evaluate the capacity of masonry railway bridge is tried to develop by means of FEM analysis. In general FEM analysis program, 3-D solid element is used for masonry structures and response spectrum analysis procedure is tried. In addition, 3-D solid element has material properties equivalent to mortar-brick composite body. Used FEM program is ABAQUS-CAE.

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Effective Boundary Conditions for FEM Analysis of Composite Laminates (복합재료 적층판의 유한요소 해석을 위한 효율적 경계조건)

  • 김택현
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.3
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    • pp.92-98
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    • 1998
  • This paper presents three boundary techniques which are useful for FEM analysis of composite laminates: 1) a rotational symmetric boundary technique . 2) a quasi three-dimensional boundary technique and 3) a contact boundary technique. The use of the rotational symmetric boundary technique is possible for a smaller FEM model. With the use of the quasi three-dimensional boundary tecnique. quasi three dimensional analysis of composite laminates can be performed on the conventional 3-D FEM program These techniques can readily be adopted to FEM programs.

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Computational finite element model updating tool for modal testing of structures

  • Sahin, Abdurrahman;Bayraktar, Alemdar
    • Structural Engineering and Mechanics
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    • v.51 no.2
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    • pp.229-248
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    • 2014
  • In this paper, the development of a new optimization software for finite element model updating of engineering structures titled as FemUP is described. The program is used for computational FEM model updating of structures depending on modal testing results. This paper deals with the FE model updating procedure carried out in FemUP. The theoretical exposition on FE model updating and optimization techniques is presented. The related issues including the objective function, constraint function, different residuals and possible parameters for FE model updating are investigated. The issues of updating process adopted in FemUP are discussed. The ideas of optimization to be used in FE model updating application are explained. The algorithm of Sequential Quadratic Programming (SQP) is explored which will be used to solve the optimization problem. The possibilities of the program are demonstrated with a three dimensional steel frame model. As a result of this study, it can be said that SQP algorithm is very effective in model updating procedure.

Prediction of Cutting Stress by 2D and 3D-FEM Analysis and Its Accuracy (2차원과 3차원 FEM 해석에 의한 절단응력의 해석 및 정도)

  • 장경호;이상형;이진형;강재훈
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.3
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    • pp.261-269
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    • 2003
  • Steel bridges, which have been damaged by load and corrosion, need repair or strengthening. In general, before the repair welding procedure, cutting procedure carry out. Therefore, the investigating of the behavior of stress generated by cutting is so important for safety of structure. Residual stress produced by gas cutting was analyzed using 2D and 3D thermal elasto plastic FEM. According to the results, the magnitude of temperature was analyzed by 2D FEM is smaller than that was analyzed using the 3D FEM program at the start and end edge of flange. And the magnitude and distribution of residual stress of perpendicular to the cutting line was analyzed by the 2D FEM program was similar to that was analyzed by the 3D FEM program. Therefore, it is possible to predict of cutting stress by 2D and 3D FEM.

A Study on the FEM/GEM for Sectional Analysis of Deep Drawing Panels (딥드로잉 판넬의 단면성형 해석을 위한 유한요소법/기하학힘평형법에 관한 연구)

  • 김종필;금영덕;이종문
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.212-217
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    • 1993
  • A 2-dimensional FEM/GEM program was developed for analyzing forming processes of an arbitrarily shaped draw-die, in which plane strain condition is assumed and linear line elements are employed. FEM formulation adopted a new algorithm for solving force equilibrium as well as non-penetration condition simultaneously. For the case of numerical divergence at nearly final forming stages and the initial guess in Newton-Raphson iterations, geometric force equilibrium method(GEM) is also introduced. The developed program was tested with the simulation of stamping processes of automotive bonnet inner pannel in order to verify the usefulness and validity of FEM/GEM formulation.

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