• Title/Summary/Keyword: 고유치 해석

Search Result 439, Processing Time 0.025 seconds

An Improved Stability Design of Plane Frames using System Buckling and Second-order Elastic Analysis (탄성좌굴 고유치 및 2차 탄성해석법을 이용한 평면강절프레임의 개선된 좌굴설계법)

  • Song, Ju-Young;Kyung, Yong-Soo;Kim, Nam-Il;Kim, Moon-Young
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.18 no.2
    • /
    • pp.159-168
    • /
    • 2005
  • An improved stability design method for beam-columns of plane frames is proposed based on system buckling analysis and second-order elastic analysis. For this, the tangent stiffness matrix of beam-column elements is first derived using stability functions and a procedure for evaluating effective buckling lengths is reviewed using elastic system buckling analysis. And then the second-order analysis procedure is presented considering $P-\Delta$ effects and is compared with the closed-form solution through numerical examples. Design examples showing the validity of the proposed method we presented and their numerical results are compared with those obtained from the conventional stability design methods. Finally some useful conclusions are drawn.

Form-Finding of Tensegrity Structures based on Eigenvalue Formulation (고유치문제에 근거한 텐세그러티 구조물의 형상탐색)

  • Jung, Mi-Roo;Kim, Jong-Su;Baek, Ki-Youl;Lee, Jae-Hong
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2010.04a
    • /
    • pp.584-587
    • /
    • 2010
  • 본 논문에서는 고유치문제에 근거한 텐세그러티 구조물의 형상탐색에 대하여 제시하고자 한다. 하지만 자기평형 응력을 구하기 위해서 정방형 행렬이 아닌 장방형 행렬을 풀어야 하는 난제가 발생하므로 선행 연구자들은 이를 해결하기 위해 내력밀도법과 일반역행렬을 이용한 방법 등을 제시하였다. 본 연구에서는 새롭게 형상을 탐색하는 방법을 제시하여 텐세그러티 구조물 및 케이블 돔 구조물의 자기평형 응력을 얻었다. 제시한 방법은 기존의 방법을 기본으로 한 모든 절점의 평형 방정식을 고유치문제로 정식화하였다. 이를 증명하기 위해 몇 가지 예제에 대하여 수치해석을 수행하였고 타당성을 검증하기 위하여 기존의 방법과 비교하였다. 제시된 방법은 기존의 방법과 같은 결과가 나왔으며 해답을 얻는 과정이 훨씬 간단하였다.

  • PDF

Partitioned structural eigenvalue analysis (부분 구조물 합성으로 이루어진 고유치 문제 해석)

  • Jung, Eui-Il;Na, Hye-Joong;No, Suk-Hong;Chun, Du-Hwan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.05a
    • /
    • pp.117-119
    • /
    • 2005
  • For large structural eigen-analysis, the whole structure is divided into some partitioned structures and through synthesis of partitioned structural model the eigen-data of structure can be obtained. In that case, eigenvalue problem consists of semidefinite mass matrix form because of displacement constraint condition. In this work the eigenvalue problem is considered by means of several method, determinant search and null space reduction method.

  • PDF

New Formulation of MNDIF Method for Eigenvalue Analysis of Plates (평판의 고정밀도 고유치 해석을 위한 새로운 MNDIF법 정식 개발)

  • Kang, Sang Wook
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2013.04a
    • /
    • pp.180-185
    • /
    • 2013
  • A new formulation of the MNDIF method is introduced to extract highly accurate natural frequencies of concave plates with arbitrary shape. Originally, the MNDIF method cannot yield accurate natural frequencies for concave plates. To overcome this weak point, a new approach of dividing a concave plate into two convex domains is proposed and the validity and accuracy is shown in a verification example.

  • PDF

New Formulation of MNDIF Method for Eigenvalue Analysis of Acoustic Cavities (음향 공동의 고정밀도 고유치 해석을 위한 새로운 MNDIF 법 정식 개발)

  • Kang, S.W.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2013.10a
    • /
    • pp.658-663
    • /
    • 2013
  • A new formulation of the MNDIF method is introduced to extract highly accurate eigenvalues of concave acoustic cavities with arbitrary shapes. It is said that the MNDIF method cannot yield accurate eigenvalues for concave cavities. To overcome this weak point, a new approach of dividing a concave cavity into two convex domains is proposed. The validity of the proposed method is shown through a case study.

  • PDF

A Solute Transport Analysis around Underground Storage Cavern by using Eigenvalue Numerical Technique (고유치 수치기법을 이용한 지하저장공동 주위의 용질이동해석)

  • Chung, Il-Moon;Kim, Ji-Tae;Cho, Won-Cheol;Kim, Nam-Won
    • The Journal of Engineering Geology
    • /
    • v.18 no.4
    • /
    • pp.381-391
    • /
    • 2008
  • The eigenvalue technique is introduced to overcome the problem of truncation errors caused by temporal discretization of numerical analysis. The eigenvalue technique is different from simulation in that only the space is discretized. The spatially discretized equation is diagonized and the linear dynamic system is then decoupled. The time integration can be done independently and continuously for any nodal point at any time. The results of eigenvalue technique are compared with the exact solution and FEM numerical solution. The eigenvalue technique is more efficient than the FEM to the computation time and the computer storage in the same conditions. This technique is applied to the solute transport analysis in nonuniform flow fields around underground storage caverns. This method can be very useful for time consuming simulations. So, a sensitivity analysis is carried out by using this method to analyze the safety of caverns from nearly located contaminant sources. According to the simulations, the reaching time from source to the nearest cavern may takes 50 years with longitudinal dispersivity of 50 m and transversal dispersivity of 5 m, respectively.

Lateral Vibration and Elastic Stability of Rectangular Plates with Cutouts (개구부를 가진 직사각형 평판구조의 진동 및 안정성 해석)

  • 이수곤;김순철;박근흥
    • Computational Structural Engineering
    • /
    • v.3 no.2
    • /
    • pp.77-88
    • /
    • 1990
  • Two perforated plates (a square plate and a rectangular plate having an aspect ratio 1.57(L/sub x/=11, L/sub y/=7)) are taken as analysis examples. Each of these plates is given some changes in the boundary conditions. The size of cutouts as well as their locations are also changed in order to examine the variation of two eigenvalues corresponding to the fundamental mode. The relationship between two eigenvalues is established by changing the magnitude of edge thrust.

  • PDF

Natural Frequencies of Simply Supported Tapered Beams (단순지지된 변단면 보의 고유진동수)

  • 김준희;김순철;이수곤
    • Journal of KSNVE
    • /
    • v.9 no.3
    • /
    • pp.607-612
    • /
    • 1999
  • Natural frequencies of non-symmetrically tapered beams with simply supported ends were determined by solving the frequency equations. In the case of symmetrically tapered beams. the finite element method was adopted for frequency computation. Computed frequencies of tapered beams were expressed as functions of taper ratio. a. and sectional properties. ( m, n).

  • PDF