• Title, Summary, Keyword: Finite element program

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Evaluation of Probabilistic Finite Element Method in Comparison with Monte Carlo Simulation

  • 이재영;고홍석
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.32 no.E
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    • pp.59-66
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    • 1990
  • Abstract The formulation of the probabilistic finite element method was briefly reviewed. The method was implemented into a computer program for frame analysis which has the same analogy as finite element analysis. Another program for Monte Carlo simulation of finite element analysis was written. Two sample structures were assumed and analized. The characteristics of the second moment statistics obtained by the probabilistic finite element method was examined through numerical studies. The applicability and limitation of the method were also evaluated in comparison with the data generated by Monte Carlo simulation.

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Inelastic vector finite element analysis of RC shells

  • Min, Chang-Shik;Gupta, Ajaya Kumar
    • Structural Engineering and Mechanics
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    • v.4 no.2
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    • pp.139-148
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    • 1996
  • Vector algorithms and the relative importance of the four basic modules (computation of element stiffness matrices, assembly of the global stiffness matrix, solution of the system of linear simultaneous equations, and calculation of stresses and strains) of a finite element computer program for inelastic analysis of reinforced concrete shells are presented. Performance of the vector program is compared with a scalar program. For a cooling tower problem, the speedup factor from the scalar to the vector program is 34 for the element stiffness matrices calculation, 25.3 for the assembly of global stiffness matrix, 27.5 for the equation solver, and 37.8 for stresses, strains and nodal forces computations on a Gray Y-MP. The overall speedup factor is 30.9. When the equation solver alone is vectorized, which is computationally the most intensive part of a finite element program, a speedup factor of only 1.9 is achieved. When the rest of the program is also vectorized, a large additional speedup factor of 15.9 is attained. Therefore, it is very important that all the modules in a nonlinear program are vectorized to gain the full potential of the supercomputers. The vector finite element computer program for inelastic analysis of RC shells with layered elements developed in the present study enabled us to perform mesh convergence studies. The vector program can be used for studying the ultimate behavior of RC shells and used as a design tool.

A Study on the Finite Element Analysis of Axisymmetric Hydrostatic Bulge forming Processes (축대칭 액압벌지 성형공정의 유한요소해석에 관한 연구)

  • Yun S. H.;Jin I. T.;Gu Y.;Ryoo I. I.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.115-119
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    • 2001
  • This paper presents development of a Finite Element Analysis program. The program was developed on the based of second-dimensional plane strain rigid plasticity finite element analysis and an implicit program is coded. The program was tested by being applied to the axisymetric hydrostatic bulge forming processes using the circle dies. By the Finite Element Analysis at the fluid in chamber and at the blank material, we could know that the hydrostatic bulge forming processes can be influenced of material, the diameter of product and the forming velocity The developed Finite Element Analysis program was approved by the analysis results about forming variables.

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Study on Strain Localization and Progressive Failure of Concrete (콘크리트의 변형률 국소화 및 진행성 파괴에 관한 연구)

  • 송하원;김형운;우승민
    • Journal of the Korea Concrete Institute
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    • v.11 no.3
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    • pp.181-192
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    • 1999
  • The progressive failure following strain localization in concrete can be analyzed effectively using finite element modeling of fracture process zone of concrete with a finite element embedded discontinuity. In this study, a finite element with embedded discontinuous line is utilized for the analysis of progressive failure in concrete. The finite element with embedded discontinuity is a kind of discrete crack element, but the difficulties in discrete crack approach such as remeshing or adding new nodes along with crack growth can be avoided. Using a discontinuous shape function for this element, the displacement discontinuity is embedded within an element and its constitutive equation is modeled from the modeling of fracture process zone. The element stiffness matrix is derived and its dual mapping technique for numerical integration is employed. Then, a finite element analysis program with employed algorithms is developed and failure analysis results using developed finite element program are verified through the comparison with experimental data and other analysis results.

Development of an Object-Oriented Finite Element Analysis Program Using J$Java^TM$ ($Java^TM$ 언어를 이용한 객체 지향 유한 요소 해석 프로그램의 개발)

  • 이정재;이호재
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.40 no.2
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    • pp.130-139
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    • 1998
  • The finite element analysis program should be prepared to deal with many of newly arising engineering problems. The sequential structured programming technique does not make a finite element method so flexible. So far, the object oriented programming technique was studied as an alternative programming paradigm. However, most of the research were in the state of the evaluation of the possibility and the applicability of the object oriented method for a finite element program. In this study, a practical object oriented finite element analysis program, OOFE_ JAVA was developed and the result of the analysis on a rectangular clamped plate was shown. The objects which compose the OOFE_JAVA were applied to several engineering problem without any modification and it was concluded that the object oriented technique was appropriate for the development of a complex and large engineering system. And a virtual machine which Java language is using can be loaded on any kinds of computer which has java interpreter regardless of the platform on which the OOFE_JAVA was developed.

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Development of Automatic Node Generation Algorithm and Preprocessing Technique for $\rho$-Version Finite Element Program ($\rho$-Version 유한요소 프로그램을 위한 자동절점생성 알고리즘 및 전처리 기법 개발)

  • 조준형;홍종현;우광성
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.69-76
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    • 1998
  • Due to the drastic improvement of computer hardware and operating system, it is easy to break through the main defects of limited computer memory and processing time, etc. To keep up with this situation, this paper is focused on developing the preprocessor program with the input method based on vector graphic editor and the preprocessing technique including automatic node generation algorithm for the $\rho$-version finite element program. To develop this preprocessor program, the special data structure and the OOP(Object Oriented Programming) have been used by the Visual Basic 4.0. The Special data structure is proposed to describe the geometric data of node numberings and coordinates suitable for the $\rho$-version finite element program, which are quite different from the comvential h-version finite element program.

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Equi-Value Line Program Development for 3-Dimensional Finite Element Models using Personal Computer (개인용 컴퓨터를 이용한 3차원 유한요소 등가곡선 프로그램 개발)

  • Lee, Seok-Soon
    • Journal of the Korean Society for Precision Engineering
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    • v.9 no.1
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    • pp.44-52
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    • 1992
  • A post-processor is developed to be effectively usable in the personal computer. 3-dimensional controur lines are shown on the surface of the finite element model and also on the 3-dimensional cutting plane, using the function linearly interpolated onto the triangular elements which are constructed on the surface or sectional polygons. And these polygons are originated from the finite element model, 3-dimensional model is projected on the plane with hidden line removal by comparision technique[6]. The graphic data file is used to increase the protability of the program. It is easy to use in the other computer system if the graphic routine adopted that computer system is developed. The developed program has wide applications in 3-dimensional finite element analysis.

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Modeling of Progressive Failure in Concrete using Discontinuous Finite Elements (불연속 요소를 사용한 콘크리트 파괴진행의 유한요소 모델링)

  • Shim, Byul;Song, Ha-Won;Byun, Keun-Joo
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.247-252
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    • 1996
  • In the concrete structures, cracks occur in various causes and the cracks seriously affect the functions of structures. The analysis techniques of progressive crack in the concrete have been improved with the advance of numerical techniques. The discrete crack model used in finite element program for the analysis of progressive failure is very effective, but it can not be easily implemented into numerical procedures because of difficult handing of nodal points in finite element meshes for crack growth. This paper introduces one of the techniques which skips the difficulty. In this paper, the modeling of progressive failure using finite element formulation is explained for the analysis of concrete fracture. The discontinuous element using the discontinuous shape function and the dual mapping technique in the numerical integration are implemented into finite element code for this purpose. It is shown that developed finite element program can predict the quasi-brittle behavior of concrete including ultimate load. The comparisons of the analysis results with other data are also shown.

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Development of a Three-Dimensional Finite Element Program for Metal Forming and its Application to Precision Coining (소성가공 공정설계용 3차원 유한요소 프로그램의 개발 및 정밀코이닝 공정설계)

  • 최한호;이진희;강범수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.7
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    • pp.1642-1650
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    • 1995
  • Process design is one of the most important fields in metal forming, where the finite element method has appeared a useful method for industrial applications. In this study, a program using the rigid plastic finite element has been developed for process design in three-dimensional plastic deformation. The surface integration for calculation of the friction between die and workpiece has been implemented with care in numerical treatment. The developed program is applied to a precision coining process of electronic components. It is confirmed that the program developed here is suitable for process design in metal forming with three-dimensional plastic deformation.

Vibration Analysis of HDD Actuator with Equivalent Finite Element Model of VCM Coil

  • Kim, Dong-Woohn;Lee, Jin-Koo;Park, No-Cheol;Park, Young-Pil
    • Journal of Mechanical Science and Technology
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    • v.17 no.5
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    • pp.679-690
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    • 2003
  • As the rate of increase in areal density of the HDD has accelerated, dynamic characteristics of the HDD actuator need to be improved with respect to the performance of the tracking servo and shock transmission. Therefore, it is important to analyze the vibration characteristic of the HDD actuator that consists of the VCM part, E-block and pivot bearing. In this paper, vibration modes of the HDD actuator are investigated the using finite element and experimental modal analyses methods. To develop a detailed finite element model, finite element models of each components of the actuator assembly are constructed and tuned to the results of the EMA. The VCM coil is modeled as an equivalent finite element model that has an orthotropic material property using auto-model updating program. Auto-model updating program with improved sensitivity based iterative method is applied to build a detailed finite element model using the result of the EMA. A detailed finite element model of the HDD actuator is then constructed and analyzed.