• Title, Summary, Keyword: Finite Element Analysis

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Analysis of Simply Supported Rectangular Plate Using Spectral Finite Element Method (스펙트럴유한요소법을 이용한 네 변이 단순지지 된 직사각형평판의 진동해석)

  • Jo, Kyung-Lim;Hong, Suk-Yoon;Song, Ji-Hun;Kim, Dong-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.85-89
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    • 2005
  • For the analysis of a vibrating two dimensional structure such as the simply supported rectangular plate, Spectral Finite Element Method (SFEM) has been studied. Under the condition that two parallel edges are simply supported at least and the other two edges can be arbitrary, Spectral Finite Element has been developed. Using this element SFEM is applied to the vibrating rectangular plate which all edges are simply supported, and obtain the frequency response function in frequency domain and the dynamic response in time domain. To evaluate these results normal mode method and finite element method (FEM) are also accomplished and compared. It is seen that SFEM is more powerful analysis tool than FEM in high frequency range.

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A Study on the Improvement of Shape Optimization associated with the Modification of a Finite Element (유한요소의 개선에 따른 형상최적화 향상에 관한 연구)

  • Sung, Jin-Il;Yoo, Jeong-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.7
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    • pp.1408-1415
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    • 2002
  • In this paper, we investigate the effect and the importance of the accuracy of finite element analysis in the shape optimization based on the finite element method and improve the existing finite element which has inaccuracy in some cases. And then, the shape optimization is performed by using the improved finite element. One of the main stream to improve finite element is the prevention of locking phenomenon. In case of bending dominant problems, finite element solutions cannot be reliable because of shear locking phenomenon. In the process of shape optimization, the mesh distortion is large due to the change of the structure outline. So, we have to raise the accuracy of finite element analysis for the large mesh distortion. We cannot guarantee the accurate result unless the finite element itself is accurate or the finite elements are remeshed. So, we approach to more accurate shape optimization to diminish these inaccuracies by improving the existing finite element. The shape optimization using the modified finite element is applied to a two and three dimensional simple beam. Results show that the modified finite element has improved the optimization results.

Automatic Quadrilateral Mesh Generation for Large Deformation Finite Element Analysis (대변형 유한요소해석을 위한 요소망 자동 생성기법)

  • 김동준;최호준;장동환;임중연;이호용;황병복
    • Transactions of Materials Processing
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    • v.12 no.3
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    • pp.194-201
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    • 2003
  • An automatic quadrilateral mesh generator for large deformation finite element analysis such as metal forming simulation was developed. The NURBS interpolation method is used for modeling arbitrary 2-D free surface. This mesh generation technique is the modified paving algorithm, which is an advancing front technique with element-by-element resolving method for paving boundary intersection problem. The mesh density for higher analysis accuracy and less analysis time can be easily controlled with high-density points, maximum and minimum element size. A couple of application to large deformation finite element analysis is given as an example, which shows versatility and applicability of the proposed approach and the developed mesh generator for large deformation finite element analysis.

Site Response Analysis in Time Domain Using Finite Element (시간영역에서 유한요소법을 이용한 지진시의 지반응답해석)

  • You, Hee-Yong;Lee, Jae-Young;Park, Young-Tack
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.6
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    • pp.45-56
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    • 2006
  • The finite element method is a practical tool to compute the response of the irregularly layered soil deposit to the base-rock motions. The method is useful not only in estimating the interaction between the structure and the surrounding soil as a whole and the local behavior of the contacting area in detail, but also in predicting the resulting behavior of the superstructure affected by such soil-structure interactions. However, the computation of finite element analysis is marched in the time domain (TD), while the site response analysis has been carried out mostly in the frequency domain (FD) with equivalent linear analysis. This study is intended to compare the results of the TD and FD analysis with focus on the peak response accelerations and the predominant frequencies, and thus to evaluate the applicability and the validity of the finite element analysis in the site response analysis. The comparison shows that one can obtain the results very close to that of FD analysis, from the finite element analysis by including sufficiently large width of foundation in the model and further by applying partial mode superposition. The finite element analysis turned out to be well agreeing with FD analysis in their computed results of the peak acceleration and the acceleration response spectra, especially at the surface layer.

Structural Dynamics Analysis of a Clamp Jointed Complex Ream by Using the Flexibility Influence Coefficient Method (유연도 영향계수법을 이용한 접촉결합부가 있는 복합구조물의 동적 해석)

  • 조재혁;김현욱;최영휴
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.528-533
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    • 1995
  • An analyical method is proposed to construct a clamp jointed structure as an equivalent stiffness matrix element in the finite element modal analysis of a complex beam structure. Static structural analysis was first made for the detail finite element model of the clamp joint. Utilizing the results of this analysis, the equivalent stiffness matrix element was buildup by using the flexibility influence coefficient method and Guyan condensation. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam. And the finite element analysis results were compared to those experimental modal analysis. Comparison shows doog agreement each other Furthermore the effects of normal contact(or clamping) load on the equivalent stiffness matrix was also examined. The equivalent stiffness matrix showed little change in spite of the remakable increase in the contact load on the clamp joint.

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Modal Test and Finite Element Model Update of Aircraft with High Aspect Ratio Wings (고세장비 항공기의 모드 시험 및 동특성 유한요소모델 개선)

  • Kim, Sang-Yong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.5
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    • pp.480-488
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    • 2012
  • The aircrafts with high aspect ratio wings made by a composite material have been developed, which enable high energy efficiency and long-term flight by reducing air resistance and structural weight. However, they have difficulties in securing the aeroelastic stability such as the flutter because of their long and flexible wings. The flutter is unstable self-excited-vibration caused by interaction between the structural dynamics and the aerodynamics. It should be verified analytically prior to first flight test that the flutter does not happen in the range of flight mission. Normally, the finite element model is used for the flutter analysis. So it is important to construct the finite element model representing dynamic characteristics similar to those of a real aircraft. Accordingly, in this research, to acquire dynamic characteristics experimentally the modal test of the aircraft with high aspect ratio composite wings was conducted. And then the modal parameters from the finite element analysis(FEA) were compared with those from the modal test. To make analysis results closer to test results, the finite element model was updated by means of the sensitivity analysis on variables and the optimization. Finally, it was proved that the updated finite element model is reliable as compared with the results of the modal test.

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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Static Analysis of Three Dimensional Solid Structure by Finite Element-Transfer Stiffness Coefficent Method Introducing Hexahedral Element (육면체 요소를 도입한 유한요소-전달강성계수법에 의한 3차원 고체 구조물의 정적 해석)

  • Choi, Myung-Soo;Moon, Deok-Hong
    • Journal of the Korea Society For Power System Engineering
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    • v.16 no.1
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    • pp.78-83
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    • 2012
  • The authors suggest the algorithm for the static analysis of a three dimensional solid structure by using the finite element-transfer stiffness coefficient method (FE-TSCM) and the hexahedral element of the finite element method (FEM). MATLAB codes were made by both FE-TSCM and FEM for the static analysis of three dimensional solid structure. They were applied to the static analyses of a very thick plate structure and a three dimensional solid structure. In this paper, as we compare the results of FE-TSCM with those of FEM, we confirm that FE-TSCM introducing the hexahedral element for the static analysis of a three dimensional solid structure is very effective from the viewpoint of the computational accuracy, speed, and storage.

Nonlinear finite element analysis of reinforced concrete structures subjected to transient thermal loads

  • Zhou, C.E.;Vecchio, F.J.
    • Computers and Concrete
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    • v.2 no.6
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    • pp.455-479
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    • 2005
  • This paper describes a 2D nonlinear finite element analysis (NLFEA) platform that combines heat flow analysis with realistic analysis of cracked reinforced concrete structures. The behavior models included in the structural analysis are mainly based on the Modified Compression Field Theory and the Distributed Stress Field Model. The heat flow analysis takes into account time-varying thermal loads and temperature-dependent material properties. The capability of 2D nonlinear transient thermal analysis is then implemented into a nonlinear finite element analysis program VecTor2(C) for 2D reinforced concrete membranes. Analyses of four numerical examples are performed using VecTor2, and results obtained indicate that the suggested nonlinear finite element analysis procedure is capable of modeling the complete response of a concrete structure to thermal and mechanical loads.

A Study on the Criterion for Membrane/Shell Mixed Element and Application to the Rigid-Plastic/Elastic-Plastic Finite Element Analysis (박막/쉘 혼합요소의 판별조건과 강소성/탄소성 유한요소해석 적용에 관한 연구)

  • Jung, Dong-Won;Yang, Kyoung-Boo
    • Journal of Ocean Engineering and Technology
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    • v.13 no.2
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    • pp.1-10
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    • 1999
  • This study is concerned with the application of new criterion for membrane/shell mixed element in the rigid-plastic finite element analysis and elastic-plastic finite element analysis. The membrane/shell mixed element can be selctively adapted to the pure stretching condition by using membrane or a shell element in the bending effect areas. Thus, membrane/shell mixed element requires a efficient criterion for a distinction between membrane and shell element. In the present study introduce the criterion using the angle of between two element and confirm a generality of criterion from appling the theory to a rigid-plastic and elastic-plastic problems.

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