• Title/Summary/Keyword: eigenvalue problem.

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A study on Stress Singularities for V-notched Cracks in Anisotropic and/or Pseudo-isotropic Dissimilar Materials

  • Cho, Sang-Bong;Kim, Jin-kwang
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.2
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    • pp.22-32
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    • 2002
  • V-notched crack problems can be formulated as eigenvalue problems. The problem ova v-notched crack in anisotropic and/or pseudo-isotropic dissimilar materials was formulated as an eigenvalue problem to discuss stress singularities. The eigenvalue problem was served by the commercial numerical program; MATHEMATICA. The specific data of eigenvalues possessing the stress singularity were obtained. Stress singularities fur v-notched cracks in anisotropic and/or pseudo-isotropic dissimilar materials were discussed according to the relation between wedge angle and material property. It was shown that there are three cases of eigenvalues possessing the stress singularity; one real, two real and one complex.

An Application of the Multigrid Method to Eigenvalue problems (복합마디방법의 고유치문제에 응용)

  • Lee, Gyou-Bong;Kim, Sung-Soo;Sung, Soo-Hak
    • The Journal of Natural Sciences
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    • v.8 no.2
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    • pp.9-11
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    • 1996
  • We apply a full mutigrid scheme to computing eigenvalues of the Laplace eigenvalue problem with Dirichlet boundary condition. We use finite difference method to get an algebraic equation and apply inverse power method to estimating the smallest eigenvalue. Our result shows that combined method of inverse power method and full multigrid scheme is very effective in calculating eigenvalue of the eigenvalue problem.

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Probabilistic Finite Element Analysis of Eigenvalue Problem(Buckling Reliability Analysis of Frame Structure) (고유치 문제의 확률 유한요소 해석(Frame 구조물의 좌굴 신뢰성 해석))

  • 양영순;김지호
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1990.10a
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    • pp.22-27
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    • 1990
  • Since an eigenvalue problem in structural analysis has been recognized as an important process for the assessment of structural strength, it is usually to be carried out the eigenvalue analysis or buckling analysis of structures when the compression behabiour of the member is dorminant. In general, various variables involved in the eigenvalue problem have also shown their variability. So it is natural to apply the probabilistic analysis into such problem. Since the limit state equation for the eigenvalue analysis or buckling reliability analysis is expressed implicitly in terms of random variables involved, the probabilistic finite element method is combined with the conventional reliability method such as MVFOSM and AFOSM for the determination of probability of failure due to buckling. The accuracy of the results obtained by this method is compared with results from the Monte Carlo simulations. Importance sampling method is specially chosen for overcomming the difficulty in a large simulation number needed for appropriate accurate result. From the results of the case study, it is found that the method developed here has shown good performance for the calculation of probability of buckling failure and could be used for checking the safety of the calculation of probability of buckling failure and could be used for checking the safely of frame structure which might be collapsed by either yielding or buckling.

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BOUNDARY VALUE PROBLEM FOR ONE-DIMENSIONAL ELLIPTIC JUMPING PROBLEM WITH CROSSING n-EIGENVALUES

  • JUNG, TACKSUN;CHOI, Q-HEUNG
    • East Asian mathematical journal
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    • v.35 no.1
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    • pp.41-50
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    • 2019
  • This paper is dealt with one-dimensional elliptic jumping problem with nonlinearities crossing n eigenvalues. We get one theorem which shows multiplicity results for solutions of one-dimensional elliptic boundary value problem with jumping nonlinearities. This theorem is that there exist at least two solutions when nonlinearities crossing odd eigenvalues, at least three solutions when nonlinearities crossing even eigenvalues, exactly one solutions and no solution depending on the source term. We obtain these results by the eigenvalues and the corresponding normalized eigenfunctions of the elliptic eigenvalue problem and Leray-Schauder degree theory.

Meshless Method Based on Wave-type Function for Accurate Eigenvalue Analysis of Arbitrarily Shaped, Clamped Plates (임의 형상 고정단 평판의 고정밀도 고유치 해석을 위한 파동 함수 기반 무요소법)

  • Kang, Sang-wook
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.5
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    • pp.602-608
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    • 2016
  • The paper proposes a practical meshless method for the free vibration analysis of clamped plates having arbitrary shapes by extending the non-dimensional dynamic influence function (NDIF) method, which was developed by the author in 1999. In the proposed method, the domain and boundary of the plate of interest are discretized using only nodes without elements unlike FEM and the system matrices are obtained by making domain nodes and boundary nodes satisfy the governing differential equation and boundary conditions, respectively. However, since the above system matrices are not square ones, the problem of free vibrations of clamped plates is not reduced to an algebraic eigenvalue problem. An additional theoretical treatment is considered to produce an algebraic eigenvalue problem. It is revealed from case studies that the proposed method is valid and accurate.

Numerical Analysis of Lightwave Modes in GRIN Optical Fibers by Using Eigenvalue (고유치를 이용한 GRIN 광섬유 내에서의 광파모드의 해석)

  • Sohn, Young-Ho
    • Convergence Security Journal
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    • v.8 no.4
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    • pp.153-159
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    • 2008
  • Graded-Index Multimode Optical fibers have recently received a lot of attention as regards their application and lightwave behavior in relation to broadband communication links. Accordingly, this aticle presents a novel lightwave mode analysis that solves the wave equation using a numerical analysis based on an eigenvalue problem method, thereby avoiding the typical complicated Bessel function method. Angular depedences and number of modes were observed as well. Future research implications will be possibly noticed such areas as bending effects and mode coupling analyses thru this research.

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DIRICHLET BOUNDARY VALUE PROBLEM FOR A CLASS OF THE NONCOOPERATIVE ELLIPTIC SYSTEM

  • JUNG, TACKSUN;CHOI, Q-HEUNG
    • Korean Journal of Mathematics
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    • v.23 no.2
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    • pp.259-267
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    • 2015
  • This paper is devoted to investigate the existence of the solutions for a class of the noncooperative elliptic system involving critical Sobolev exponents. We show the existence of the negative solution for the problem. We show the existence of the unique negative solution for the system of the linear part of the problem under some conditions, which is also the negative solution of the nonlinear problem. We also consider the eigenvalue problem of the matrix.

EXISTENCE OF A POSITIVE INFIMUM EIGENVALUE FOR THE p(x)-LAPLACIAN NEUMANN PROBLEMS WITH WEIGHTED FUNCTIONS

  • Kim, Yun-Ho
    • Korean Journal of Mathematics
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    • v.22 no.3
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    • pp.395-406
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    • 2014
  • We study the following nonlinear problem $-div(w(x){\mid}{\nabla}u{\mid}^{p(x)-2}{\nabla}u)+{\mid}u{\mid}^{p(x)-2}u={\lambda}f(x,u)$ in ${\Omega}$ which is subject to Neumann boundary condition. Under suitable conditions on w and f, we give the existence of a positive infimum eigenvalue for the p(x)-Laplacian Neumann problem.

Inverse Eigenvalue Problems with Partial Eigen Data for Acyclic Matrices whose Graph is a Broom

  • Sharma, Debashish;Sen, Mausumi
    • Kyungpook Mathematical Journal
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    • v.57 no.2
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    • pp.211-222
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    • 2017
  • In this paper, we consider three inverse eigenvalue problems for a special type of acyclic matrices. The acyclic matrices considered in this paper are described by a graph called a broom on n + m vertices, which is obtained by joining m pendant edges to one of the terminal vertices of a path on n vertices. The problems require the reconstruction of such a matrix from given partial eigen data. The eigen data for the first problem consists of the largest eigenvalue of each of the leading principal submatrices of the required matrix, while for the second problem it consists of an eigenvalue of each of its trailing principal submatrices. The third problem has an eigenvalue and a corresponding eigenvector of the required matrix as the eigen data. The method of solution involves the use of recurrence relations among the leading/trailing principal minors of ${\lambda}I-A$, where A is the required matrix. We derive the necessary and sufficient conditions for the solutions of these problems. The constructive nature of the proofs also provides the algorithms for computing the required entries of the matrix. We also provide some numerical examples to show the applicability of our results.