• Title, Summary, Keyword: 비선형동적해석

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Structural Parameters and Modeling Technique for Prediction of Dynamic Response of a One-story Building with a Flexible Diaphragm (유연한 지붕을 갖는 단층 건물의 동적응답 예측을 위한 해석모델링 방법과 구조변수의 설정)

  • ;Donald W. White
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.3
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    • pp.271-280
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    • 2003
  • The purpose of the study presented in this paper is to develope the general model for capture of the linear and nonlinear response of a flexible diaphragm building in which there are significant contributions from the out-of-plane walls. Two single-story single-diaphragm half scale reinforced masonry buildings were tested by researchers at the United States Army Construction Engineering Research Laboratory (CERL). The first had a metal deck diaphragm. The second specimen had a diaphragm with a single layer of diagonal lumber sheathing, A multiple degree of freedom (MDOF) approach is adopted in this paper. The required stiffnesses and strengths of the components within this model are determined.

Effect of Aerodynamic Nonlinearity on Drive-Train of Wind Turbine (공기역학적 비선형성이 풍력발전기 드라이버-트레인에 미치는 영향)

  • Lim, Chae-Wook
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.235-235
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    • 2010
  • 풍력발전기의 공기역학적 비선형성은 풍력발전기 전체 시스템의 동적특성에 영향을 미친다. 풍력발전기의 드라이버-트레인의 감쇠가 매우 작으므로 풍력발전기를 제어함에 있어 드라이버-트레인의 동적특성은 중요하게 고려되어야 한다. 본 논문에서는 풍속에 따른 공기역학적 비선형성이 드라이버-트레인의 동적특성에 미치는 영향을 해석적으로 살펴보고자 한다.

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Dynamic Analysis of Geometric Nonlinear Behavior of Suspension Bridges under Random Wind Loads (랜덤풍하중에 대한 현수교의 기하학적 비선형 거동의 동적해석)

  • Yun, Chung Bang;Hyun, Chang Hun;Yoo, Je Nam
    • Journal of The Korean Society of Civil Engineers
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    • v.8 no.2
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    • pp.185-196
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    • 1988
  • In this study, a method of nonlinear dynamic analysis of suspension bridges subjected to random wind loads is pre.sented. The nonlinearity considered is the one due to the interaction between the motion of the bridge girder and the tertsion variation of the main cables. The equation of motion is formulated using a continuum approach. The coupling between the vertical and torsional motions are included in the analysis. The equation of motion is solved by using the mode superposition method. The analysis is carried out in the frequency domain utilizing the stochastic linearization technique on to the modal equations. In the linearization procedure, the nonlinear terms are approximated as linear ones with constant terms. The verification of the method has been performed on a case with four modal degrees of freedom. Example analyses are carried out on two suspension bridges for various wind speeds and wind force parameters. Numerical results indicate that, by including the nonlinearity into the analysis, the dynamic responses of the bridges, particularly in the vertical direction, change considerably.

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A Method for Vibration and Sensitivity Analysis of Structure Systems with Non-linear Characteristics (비선형 특성을 가진 구조시스템의 진동과 감도해석 방법)

  • Moon, Byung-Young;Kim, Sa-Soo;Iwatsubo, Takuzo
    • Journal of Ocean Engineering and Technology
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    • v.13 no.4
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    • pp.10-18
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    • 1999
  • 본 논문에서는 대형구조물의 해석에 있어서 부분구조합성법과 섭동법을 이용하여 복잡한 비선형시스템의 해석방법을 제안하였다. 해석방법은 전체시스템을 먼저 몇 개의 분계로 분할한다. 각 분계의 운동방정식에 비선형항이 존재하여도 전체시스템의 지배적 진동모드는 선형모드라는 가정하에 이 시스템의 각 분계를 모드좌표로 변환한다. 이때, 비선형항은 근사적으로 변환한다. 그리고 섭동법을 이용하여 각 분계의 모드좌표방정식은 섭동좌수별로 정식화되어 순차적으로 구해진다. 비선형의 감도는 비선형계수로 정의되고, 그에 상응하는 강성에 의해 구해진다. 제안된 해석방법으로 비선형회전체, 비선형 베어링-페데스탈로 구성된 대형시계구조물의 진동을 해석하였다. 해석방법의 유효성을 평가하기 위해 응답의 정도와 계산소요시간을 유한요소법의 결과와 비교 분석하였다.

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Development of Nonlinear Dynamic Program for Buckling Analysis of Plane Circular Arches (평면 원호아치의 좌굴해석을 위한 동적 비선형해석 프로그램의 개발)

  • 허택녕;오순택
    • Computational Structural Engineering
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    • v.7 no.1
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    • pp.69-81
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    • 1994
  • This paper summarizes a dynamic analysis of the shallow circular arches under dynamic loading, considering the geometric nonlinearity. The major emphasis is placed on the development of computer program, which is utilized for the analysis of the nonlinear dynamic behavior and for the evaluation of the critical buckling loads of the shallow circular arches. Geometric nonlinearity is modeled using Lagrangian description of the motion and a finite element analysis procedure is used to solve the dynamic equation of motion. A circular arch subject to normal step load is analyzed and the results are compared with those from other researches to verify the developed program. The critical buckling loads of arches are estimated using the non-dimensional time, load and shape parameters and the results are also compared with those from the linear analysis. It is found that geometric nonlinearity plays and important role in the analysis of shallow arches and the probability of buckling failure is getting higher as arches become shallower.

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Finite element dynamic analysis of laminated composite shell structures considering geometric nonlinear effects (기하학적 비선형 효과를 고려한 복합재료 적층 쉘 구조의 유한요소 동적 해석)

  • Lee, Sang-Youl
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.11
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    • pp.5979-5986
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    • 2013
  • This study carried out a geometrical nonlinear dynamic analysis of laminated composite shell structures. Based on the first-order shear deformation shell theory and nonlinear formulation of Sanders, the Newmark method and Newton-Raphson iteration are used for dynamic solution considering nonlinear effects. The effects of radius, fiber angles, and layup sequences on the nonlinear dynamic response for various parameters are studied using a nonlinear dynamic finite element program developed for this study. The several numerical results were in good agreement with those reported by other investigators for square composite plates, and the new results reported in this paper show the significant interactions between the radius, fiber angles and layup sequence in the laminate. Key observation points are discussed and a brief design guideline of laminated composite shells is given.

Prediction Approach with a Stiffness Measure in Nonlinear Dynamic Analysis of Reinforced Concrete Structures (철근 콘크리트 구조물의 비선형 동적 해석을 위한 성치 측정에 의한 예측 접근법)

  • 김교신;전경훈
    • Journal of the Earthquake Engineering Society of Korea
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    • v.1 no.1
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    • pp.1-10
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    • 1997
  • Current seismic design philosophy for reinforced concrete (RC) structures on energy dissipation through large inelastic defomations. A nonlinear dynamic analysis which is used to represent this behavior is time consuming and expensive, particularly if the computations have to be repeated many times. Therefore, the selection of an efficient yet accurate alogorithm becomes important. The main objective of the present study is to propose a new technique herein called the prediction approach with siffness measure (PASM) method in the convetional direct integration methods, the triangular decomposition of matrix is required for solving equations of motion in every time step or every iteration. The PASM method uses a limited number of predetermined decomposed effective matrices obtained from stiffness states of the structure when it is deformed into the nonlinear range by statically applied cyclic loading. The method to be developed herein will reduce the overall numerical effort when compared to approaches which recompute the stiffness in each time step or iteration.

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A New Hybrid Method for Nonlinear Soil-Structure Interaction Analysis (비선형 지반-구조물 상호작용해석을 위한 새로운 복합법)

  • 김재민;최준성;이종세
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.6
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    • pp.1-7
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    • 2003
  • This paper presents a novel hybrid time-frequency-domain method for nonlinear soil-structure interaction(SSI) analysis. It employs, in a practical manner, a computer code for equivalent linear SSI analysis and a general-purpose nonlinear finite element program. The proposed method first (calculates dynamic responses on a truncated finite element boundary utilizing an equivalent linear SSI program in the frequency domain. Then, a general purpose nonlinear finite element program is employed to analyze the nonlinear SSI problem in the time domain, in which boundary conditions at the truncated boundary are imposed with the responses calculated in the previous frequency domain SSI analysis, In order to validate the proposed method, seismic response analyses are carried out for a 2-D underground subway station in a multi-layered half-space, For the analyses, a equivalent linear SSI code KIESSI-2D is coupled to ANSYS program. The numerical results indicate that the proposed methodology can be a viable solution for nonlinear SSI problems.

A Study on the Dynamic Characteristics of Tension Structures according to Initial Tension Forces and Equilibrium Shape (초기인장력과 평형형상을 고려한 인장구조물의 동적 특성에 대한 연구)

  • Chang, Dong Il;Kim, Hak Jae
    • Journal of Korean Society of Steel Construction
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    • v.10 no.1
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    • pp.73-83
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    • 1998
  • Considering dynamic behaviors according to initial tension forces, geometric nonlinearity and the effect of higher eigen modes to participate in dynamic behaviors increase as initial tension forces decrease, and from phase portrait we can realize that period attractors are produced in many area with complexity. If initial tension forxes increase, difference between linear and nonlinear solutions will decrease and the first eigen mode dominate the dynamic behaviors and observing phase portrait, period attractors appear in certain area regularly. These results may offer meaningful informations to nonlinear dynamic analysis using modal reduction methods such as Lanczos modal analysis. And actually nonlinear dynamic analysis needs very large computational efforts. So, if we determine the number of eigen modes to take part in modal analysis corresponding to initial tension forces we will get more accurate data close to exact nonlinear dynamic solutions.

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Dynamic Nonlinear Analysis of Stiffened Shell Structures (보강된 쉘구조의 동적 비선형해석)

  • 최명수;김문영;장승필
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.3
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    • pp.57-64
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    • 2001
  • For the dynamic nonlinear analysis of stiffened plate and shell structures, total Lagrangian formulation is presented based upon the degenerated shell element considering finite rotation effects. Assumed strain concept is adopted in order to overcome shear locking phenomena and to eliminate spurious zero energy mode. In the elasto-plastic analysis, the return mapping algorithm based on the consistent elasto-plastic tangent modulus is applied to collapse analysis of shell structures. Newmark integration method is used for dynamic nonlinear analysis of shell structures under dynamic forces.

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