• Title, Summary, Keyword: Boundary element method

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The Prediction Modelling on the Stress Intensity Factor of Two Dimensional Elastic Crack Emanating from the Hole Using Neural Network and Boundary element Method (신경회로망과 경계요소법을 이용한 원공에서 파생하는 2차원 탄성균열의 응력세기계수 예측 모델링)

  • Yun, In-Sik;Yi, Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.3
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    • pp.353-361
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    • 2001
  • Recently the boundary element method has been developed swiftly. The boundary element method is an efficient and accurate means for analysis of two dimensional elastic crack problems. This paper is concerned with the evaluation and the prediction of the stress intensity factor(SIF) for the crack emanating from the circular hole using boundary element method-neural network. The SIF of the crack emanating from the hole was calculated by using boundary element method. Neural network is used to evaluate and to predict SIF from the results of boundary element method. The organized neural network system (structure of four processing element) was learned with the accuracy 99%. The learned neural network system could be evaluated and predicted with the accuracy of 83.3% and 71.4% (in cases of SIF and virtual SIF). Thus the proposed boundary element method-neural network is very useful to estimate the SIF.

On boundary discretization and integration in frequency-domain boundary element method

  • Fu, Tia Ming;Nogami, Toyoaki
    • Structural Engineering and Mechanics
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    • v.6 no.3
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    • pp.339-345
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    • 1998
  • The computation size and accuracy in the boundary element method are mutually coupled and strongly influenced by the formulations in boundary discretization and integration. This aspect is studied numerically for two-dimensional elastodynamic problems in the frequency-domain. The localized nature of error is observed in the computed results. A boundary discretization criterion is examined. The number of integration points in the boundary integration is studied to find the optimum number for accuracy. Useful information is obtained concerning the optimization in boundary discretization and integration.

A Composite Method of Finite Element and of Boundary Integral Methods for the Magnetic Field Problems with Open Boundary (유한요소법 및 경계적분법의 혼합법에 의한 개 영역 자장문제 해석)

  • 정현교;함송엽
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.36 no.6
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    • pp.396-402
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    • 1987
  • A Composite method of finite element and boundary integral methods is introduced to solve the magnetostatic field problems with open boundary. Only the region of prime interest is taken as the compution region where the finite element method is applied. The boundary conditions of the region are dealt with using boundary integral method. The boundary integration in the boundary integral method is done by numerical and analytical techniques repectively. The proposed method is applied to a simple linear problem, and the results are compared with those of the finite element method and the analytic solutions. It is concluded that the proposed method gives more accurate results than the finite element method under the same computing efforts.

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Virtual boundary element-equivalent collocation method for the plane magnetoelectroelastic solids

  • Yao, Wei-An;Li, Xiao-Chuan;Yu, Gui-Rong
    • Structural Engineering and Mechanics
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    • v.22 no.1
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    • pp.1-16
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    • 2006
  • This paper presents a virtual boundary element-equivalent collocation method (VBEM) for the plane magnetoelectroelastic solids, which is based on the fundamental solutions of the plane magnetoelectroelastic solids and the basic idea of the virtual boundary element method for elasticity. Besides all the advantages of the conventional boundary element method (BEM) over domain discretization methods, this method avoids the computation of singular integral on the boundary by introducing the virtual boundary. In the end, several numerical examples are performed to demonstrate the performance of this method, and the results show that they agree well with the exact solutions. So the method is one of the efficient numerical methods used to analyze megnatoelectroelastic solids.

Application of Semi-infinite Boundary Element Method for Tunnel Vibration Analysis (터널 진동해석을 위한 반무한 경계요소법의 적용)

  • 김문겸;이종우;전제성
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.128-136
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    • 1994
  • In this study, dynamic boundary element method using mass matrix is derived, using fundamental solutions for the semi-infinite domain. In constituting boundary integral equations for the dynamic equilibrium condition, inertia term in the form of domain integral is transformed into boundary integral form. Corresponding system equations are derived, and a boundary element program is developed. In addition, equations for free vibration is formulated, and eigenvalue analysis is performed. The results from the dynamic boundary element analysis for a tunnel problem are compared with those from the finite element analysis. According to the comparison, boundary element method using mass matrix is consistent with the results of finite element method. Consequently, in tunnel vibration problems, it results in reasonable solution compared with other methods where relatively higher degree of freedoms are employed.

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Development of a Wall Analysis Model Grafting FE-BEM (FE-BEM을 결합한 벽체의 해석모델 개발)

  • Jung , Nam-Su;Choi, Won;Lee, Ho-Jae;Kim , Han-Joong;Lee , Jeong-Jae;Kim, Jong-Ok
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.5
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    • pp.61-68
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    • 2004
  • Methodologies of the finite element and boundary element are combined to achieve an efficient and accurate analysis model of frame structure containing shear wall. This model analyzes the frame by employing the finite element method and the shear wall by boundary element method. This study is applicable to a specific situation, where the boundary element is surrounded by finite elements. By employing FE dominant method in which boundary stiffness matrix is transformed into finite element stiffness matrix, boundary element and finite element method are combined to analyze frame structure with walls.

A Composite of FEM and BIM Dealing with Neumann and Dirichlet Boundary Conditions for Open Boundary magnetic Field Problems (개량역 자장간의 해석에 있어서 Neumann 및 Diichlet 경계조건을 고려한 유한요소법 및 경계적분법)

  • 정현교;한송엽
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.36 no.11
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    • pp.777-782
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    • 1987
  • A new composite method of finite element and boundary integral methods is presented to solve the two dimensional magnetostatic field problems with open boundary. The method can deal with the current source of the boundary integral regin where the boundary integral method is applied, and also Neumann and Dirichlet boundary conditions at the interfacial boundary between the boundary integral region and the finite element region where the finite element method is applied. The new approach has been applied to a simple linear problem to verify the usefulness. It is shown that the proposed algorithm gives more accurate results than the finite element methed under the same elementdiscretization.

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1D finite element artificial boundary method for layered half space site response from obliquely incident earthquake

  • Zhao, Mi;Yin, Houquan;Du, Xiuli;Liu, Jingbo;Liang, Lingyu
    • Earthquakes and Structures
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    • v.9 no.1
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    • pp.173-194
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    • 2015
  • Site response analysis is an important topic in earthquake engineering. A time-domain numerical method called as one-dimensional (1D) finite element artificial boundary method is proposed to simulate the homogeneous plane elastic wave propagation in a layered half space subjected to the obliquely incident plane body wave. In this method, an exact artificial boundary condition combining the absorbing boundary condition with the inputting boundary condition is developed to model the wave absorption and input effects of the truncated half space under layer system. The spatially two-dimensional (2D) problem consisting of the layer system with the artificial boundary condition is transformed equivalently into a 1D one along the vertical direction according to Snell's law. The resulting 1D problem is solved by the finite element method with a new explicit time integration algorithm. The 1D finite element artificial boundary method is verified by analyzing two engineering sites in time domain and by comparing with the frequency-domain transfer matrix method with fast Fourier transform.

Efficient Method of Singular Value for Inverse Problem (역 문제에 대한 특이치 효율화)

  • Park, Sung-Oan
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.21 no.2
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    • pp.232-240
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    • 2012
  • This study proposed efficient method of singular value for inverse problem, linear approximation of contact position and loading in single and double meshing of transmission contact element, using 2-dimension model considered near the tooth by root stress. Determination of root stress is carried out for the gear tooth by finite element method and boundary element method. Boundary element discretization near contact point is carefully performed to keep high computational accuracy. The predicted results of boundary element method are good accordance with that of finite element method.

Analysis of Torque on Spur Gear by Inverse Problem (역문제에 의한 평치차의 토크 해석)

  • 박성완
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.5
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    • pp.24-33
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    • 2003
  • This study proposed a technique for inverse problem, linear approximation of contact position and loading in single and double meshing of transmission contact element using 2-dimension model considered near the tooth by root stress. Determination of root stress is carried out far the gear tooth by finite element method and boundary element method. Boundary element discretization near contact point is carefully performed to keep high computational accuracy. The predicted results of boundary element method are good accordance with that of finite element method.