• Title/Summary/Keyword: 판폭비

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A Fructure Mechanics Analysis on the Crack in the Variable Thickness Plate Having Fillet (필렛을 갖는 변후부재의 균열에 대한 파괴역학적 연구)

  • 양원호;최용식;조명래
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.5
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    • pp.1433-1438
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    • 1991
  • 본 연구에서는 팔렛을 갖는 유한폭 변후판재 내의 모드 Ⅰ균열에 대하여 3차 원 유한요소법으로 응력확대계수를 수치해석하였다.

Analysis of Fatigue Crack Growth Behavior in the Stiffened Panels with Bonded Symmetric Stiffener (접착이음 보강판의 피로거동해석)

  • 이환우;강선규
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.5
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    • pp.168-172
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    • 2000
  • The stiffened panel is representative of a large portion of aircraft construction and therefore has much practical importance. In this paper, the influence of various shape parameters on the stress intensity factors and the fatigue crack growth in the panels with bonded composite stiffeners are studied experimentally. Results are presented as crack growth rates for various values of crack lengths, stiffness ratios, and stiffening Materials.

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Stress Intensity Factors of Combined Mode(Mode I/II) Crack in a Variable Thickness Plate (두께가 변화하는 부재 내의 혼합모드(모드 I/II) 균열의 응력확대계수)

  • 조명래;양원호;최용식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.8
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    • pp.1875-1882
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    • 1993
  • Variable thickness plates are commonly used as structural members in the majority of industrial sectors. Previous fracture mechanics researches on variable thickness plates were limited to mode I loading cases. In practice, however, cracks are usually located inclined to the loading direction. In this respect, combined mode(mode I/II) stress intensity factors $K_{I}$ and $K_{II}$ at the crack tip for a variable thickness plate were obtained by 3-dimensional finite element analysis. Variable thickness plates containing a slant edge crack were chosen. The parameters used in this study were dimensionless crack $length{\lambda}$, slant $angle{\alpha}$, thickness $ratio{\beta}$ and width ratio{\omega}$. Stress intensity factors were calculated by crack opening displacement(COD) and crack sliding displacement(CSD)method proposed by Ingraffea and Manu.

A Study on the Proper Fillet Shape in Fracture Mechanical Aspect (파괴역학적 관점에서의 적정 필렛 형상에 관한 연구)

  • Kim, Chul;Yang, Won-Ho;Cho, Myoung-Rae
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.214-220
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    • 1999
  • In order to use effectively a machinery part with fillet, it is necessary to determine a proper fillet shape in design step, Study of such problem by fracture mechanical criterion is rare. So, this paper focuses on the design of fillet radius in fracture mechanical aspect. Finite element method was used to obtain crack tip stress intensity factor. Stress intensity factor was calculated by COD(crack opening displacement0method proposed by Ingraffea and Manu. The parameter used in this study are thickness ration, filet radium and crack length . If fillet radius increase , crack propagation may be accelerated. Critical crack length is inversely proportional to fillet radius.

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Combined Mode I / III Stress Intensity Factor Analysis of a Crack in a Variable Thickness Plate (두께가 변화하는 부재 내의 혼합모드 I / III 균열의 응력확대 계수해석 - 3차원 유한요소해석 중심으로 -)

  • 양원호;최용식;조명래
    • Journal of the korean Society of Automotive Engineers
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    • v.15 no.2
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    • pp.112-120
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    • 1993
  • Variable thickness plates are commonly encountered in the majority of mechanical/structural components of industrial applications. And, as a result of the unsymmetry of the structure or the load and the anisoptropy of the materials, the cracks in engineering structures are generally subjected to combined stresses. In spite of considerable practical interest, however, a few fracture mechanics study on combined mode crack in a variable thickness plate have carried out. In this respect, combined mode 1/3 stress intensity factors $K_{1}$ and $K_{3}$ at the crack tip for a variable thickness plate were obtained by 3-dimensional finite element analysis. Variable thickness plates containing a central slant crack were chosen. the parameters used in this study were dimensionless crack length .lambda. crack slant angle .alpha, thickness ratio .betha. and width ratio .omega. Stress intensity factors were calculated by crack opening displacement(COD) and crack tearing displacement(CTD) method proposed by Ingraffea and Manu. The effect of thickness ratio .betha. on $K_{1}$ is relatively great in comparison to $K_{3}$.

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A Study on Width Spread in 2-High Rolling of Rectangular Bars (각재의 냉간 2단 압연에 있어서의 폭 증가율에 관한 연구)

  • 윤상건;김동원;인정제
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.5
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    • pp.831-836
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    • 1989
  • It was found that the effect of the friction between the roll and the workpiece on the spread ratio in flat rolling processes varies with the width-to-height ratio and the reduction in height by Tozawa, Oh and kobayashi numerically. In the present study, the barrelling profile accompanying the width spread was predicted by using the energy method proposed by Kato, which is known to be one of the most advanced method for the three dimensional analysis of the rolling process. The modified velocity field was applied to compute the width spread and the result was verified by experiments. the analysis by the energy method gave the result that the spread ratio increases with the friction factor when the width-to-height ratio is 1 and decreases when the ratio is larger then 2, being consistent with the results of Tozawa and Oh. Nevertheless the cold rolling experiment for pure aluminium showed that the spread ratio decreases with the increasing friction factor irrespective of the width-to-hight ratio.