• Title/Summary/Keyword: stiffened

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보강 원통형 몰수체의 음향방사 해석과 FFT에 의한 진동 해석 (Acoustic Radiation Analysis of Stiffened Cylindrical shell and Vibrational Velocity by FFT)

  • 배수룡;이헌곤;홍진숙
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1993년도 춘계학술대회논문집; 한국과학연구소, 21 May 1993
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    • pp.128-133
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    • 1993
  • 본 연구에서는 보강 원통쉘에 대하여 주위 유체의 영향을 고려하여 진동 및 음향방사를 해석하였다. 원통셀의 운동방정식은 Donnell 이론을 적용하였으 며, Contour 적분을 풀지 않고 FFT 알고리즘(Fast Fourier Transform Algorithm)을 이용하여 원통쉘의 진동을 계산하였다. 현재까지의 방사패턴에 관한 연구는 주로 원주 방향에 집중되어 왔으나, 보강 원통쉘의 방사패턴은 원추파 모형에 가까우므로 극좌표 .theta. 방향에 대한 음향방사 패턴에 관한 연구가 이루어져야 한다. 그러므로, 본 연구에서는 극좌표에 관한 방사패턴 에 관하여 주로 고찰하였다.

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보강판의 초기결함 민감성 연구 (Initial Imperfection Sencitivity in Stiffened Plates)

  • 김천욱;원종진
    • 대한기계학회논문집
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    • 제8권3호
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    • pp.264-273
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    • 1984
  • 초기경향이 있는 보강평판의 비선형 운동 방정식을 Galerkin method에 의하여 유도하였다. Runge Kutta method를 사용하여 step-load를 받고 있는 보강평판의 동적 좌굴문제의 수치해를 구하였다. 정적 좌굴실험에 의하여 좌굴하중을 결정함에 있어 동적 해석법을 응용할 수 있음을 입증하였으며, step-load를 받는 보강평판의 동적 좌굴해석으로 정적좌굴의 초기결함 민감성을 해 석하였다. 보강평판의 초기결함민강성은 평판보다 훨씬 낮으며 보강재의 편심비가 높을수록 민감 성은 둔화된다.

Design Study of Adhesively Bonded Structures

  • Chung, Jae-Ung
    • 한국CDE학회논문집
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    • 제14권2호
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    • pp.122-128
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    • 2009
  • The failure responses of adhesively bonded, hat stiffened structures are studied through numerical analysis using the finite element method. The responses are evaluated numerically for the bonded hat section/substrate structures containing different combinations of materials. It is studied what kind of material combinations causes the easier crack initiation in the structure. This study is conducted under plane strain conditions and J-integral via a commercial code ABAQUS as a total critical energy release criterion was used for observation on crack initiation. Also, the influence of adhesive on the structure is studied.

Wind tunnel test research on aerodynamic means of the ZG Bridge

  • He, Xiangdong;Xi, Shaozhong
    • Wind and Structures
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    • 제2권2호
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    • pp.119-125
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    • 1999
  • The ZG Bridge(preliminary design), with unfavorable aerodynamic stability characteristics, is a truss-stiffened suspension bridge, its critical wind speed of flutter instability is much lower than that of code requirement, In the present paper, based on both aerostatic and aeroelastic section model wind tunnel test, not only effects of some aerodynamic means on aerodynamic stability of its main girder are investigated, but also such effective aerodynamic means of it as flap and plate-like center stabilizer are concluded.

환보강재를 가진 T형 관이음부의 축방향 강도 평가 (Axial Strength Evaluation for Tubular T-Joints with Internal Ring Stiffener)

  • 조현만;류연선;김정태
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.269-276
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    • 2001
  • Tubular structures are widely used for offshore platforms and truss type structures. In this paper, nonlinear finite element analysis is used to assess the static strength of stiffened tubular T-joints subjected to compressive brace loading. This joints was modelled with and without internal ring stiffener According to variation of ring geometries, the effect of ring stiffener for T-joints are investigated. Internal ring stiffener is found to be efficient improving ultimate strength of tubular joints. Relations of ring thickness and axial strength are observed considering geometric parameters of ring stiffeners.

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단부평판 접합부의 극한저항능력 평가를 위한 비선형 유한요소해석 모델 (Nonlinear Finite Element Analysis Model for Ultimate Capacity Estimation of End-Plate Connection)

  • 최창근;정기택
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1992년도 가을 학술발표회 논문집
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    • pp.23-28
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    • 1992
  • The ultimate capacity of end-plate connection is investigated through nonlinear finite element analysis. The example models are divided into stiffened case and unstiffened one. The refined finite element models are analyzed by utilizing a general purpose structural analysis computer program ADINA and the moment-rotation relationships of the connection are determined. The results are compared with the regression equation deduced by Krishnamurthy. It is planned to deduce a bilinear regression equation through a parametric study on various dimensions of the connection.

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판 및 셸의 편심 보강 유한 요소 (Stiffener Elements of Eccentrically Stiffened Plate/Shell)

  • 김용우;박건순;민옥기
    • 대한기계학회논문집
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    • 제15권3호
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    • pp.771-788
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    • 1991
  • 본 연구에서는 편심된 강성 강화 부재가 붙어 있는 얇은 판 또는 얇은 셸에 대해 유한 요소 해석을 할 때, 편심된 강성 강화 부재를 개별된 요소로서 정확히 묘사 할 수 있도록, 일반적인 보 이론을 기초로 하여 2개의 절점을 갖고, 각 절점당 6자유 도를 갖는 3차원 편심 보 요소(offset beam element)에 대하여 수식화하여 변위와 응 력을 계산한다.

점탄성보로 보강된 평판의 진동해석 (Vibration Anatysis on plates Stffened wlth Viscoelastic Beams)

  • 최장우;정석주;정강
    • 한국안전학회지
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    • 제4권1호
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    • pp.47-58
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    • 1989
  • This paper treats the vibration analysis of a simply supported rectangular plate stiffened with viscoelastic beams. The effect of viscoelastic beams on the vibration of the plate is analyzed by using Dirac delta function and the equation of motion can be expressed only one equation. The frequency equation is obtained by applying Laplace transformation. The effect of volumes, numben and aspect ratios of beam on the frequency of the plate is analyzed.

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Advanced Idealized Structural Units Considering Excessive Tension-Deformation Effects

  • Paik, Jeom-Kee
    • Journal of Hydrospace Technology
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    • 제1권1호
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    • pp.125-145
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    • 1995
  • In this paper, three kinds of the existing idealized structural units, namely the idealized beam-column units the idealized unstiffened plate unit and the idealized stiffened plate unit are expanded to deal with the excessive tension-deformation effects. A simplified mechanical model far the stress-strain relationship of steel members under tensile load is suggested. The 1/3-scale hull model for a leander class frigate under sagging moment tested by Dow is analyzed, and it is shown that the excessive tension-deformation is a significant factor affecting the progressive collapse behavior, particularly in the post-collapse range.

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