• 제목/요약/키워드: notches

검색결과 193건 처리시간 0.024초

구조용 강의 굽힘 피로강도에 미치는 Notch의 영향 (The Effect of Notch on Bending Fatigue Strength of Structural Steel)

  • 박노석
    • Journal of Biosystems Engineering
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    • 제1권1호
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    • pp.64-72
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    • 1976
  • This experimental work was carried out to investigate the fatigue bending strength on various shapes and sizes of notches of the domestically manufactured steel plate. The notch types tested were a circular hole, U-and V-notches. The S-N diagram for different notch shapes were discussed in relation to plan bending strength and stress concentration factor of notches .The results of the experiments are summarized as follows : (1) The difference between stress concentration factor and notch factor was greater as the radium of notch root became smaller, and these values approached to an identical value as the radium of notch root increased. (2) It was shown that the plane bending fatigue limit of bar without notch for the hotrolled steel having the tensile strength of 33.1kg/$mm^2$was 17.0kg/$mm^2$. (3) U-and V-notch had a greater effect of stress concentration factor on the endurance limit, but O-hole showed the same effect only for $\o\pm2mm$. (4) For the same radius of notch root, U-notch showed a lower value of fatigue limit compared to V-notch and O-hole.

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An iteration approach for multiple notch problem based on complex variable boundary integral equation

  • Chen, Y.Z.
    • Structural Engineering and Mechanics
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    • 제41권5호
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    • pp.591-604
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    • 2012
  • This paper provides an iteration approach for the solution of multiple notch problem, which is based on the complex variable boundary integral equation (CVBIE). The contours of notches are applied by some loadings. The source points are assumed on the boundary of individual notch and the displacements along the boundaries become unknowns to be investigated. After discretization of the BIE, many influence matrices are obtained. One does not need to assemble many influence matrices into a larger matrix. This will considerably reduce the work in the program. The displacements along the many boundaries can be obtained from an iteration. There is no limitation for the configuration of notches. Several numerical examples are provided to prove the efficiency of the suggested approach.

Controlled Microstructure for Optimum Fatigue Performance

  • Takeda, Yoshinobu;Bergmark, Anders;Alzati, Luigi;Bengtsson, Sven
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.132-133
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    • 2006
  • Optimized choice of material for two principally different types of PM components is presented. The first is characterized by high stresses in areas with high stress concentrations (for example synchronizer hubs with very sharp notches, typically <0.25mm in the pre-synchronizer slot and the inner splines). The second type has slightly larger notch radii (small spur gears and sprockets with typically notch radii between 1- 3mm). Diffusion alloyed materials are well suited for sharp notch components. Pre-alloyed materials are also well suited for applications with sharp notches if compressive residual stresses in the notch roots are created by appropriate process control. A free choice of material is available for components with the larger notch radii.

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유전체 도파관 격자구조에서 TM-TE 모드 변환에 관한 연구 (A Study of the TM-TE Mode Conversion in Dielectric Waveguide Grating Structures)

  • Park, Dong-Chul
    • 대한전자공학회논문지
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    • 제24권4호
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    • pp.553-558
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    • 1987
  • A design method of dielectric image-guide grating structures which are applicable for the millimeter-wave system is presented. A dielectric image-guide grating with notches in the sides and also another grating with notches in the top have been designed, fabricated and tested with TM-and TE-mode excitations. From the esperimental results the relatin between TM-TE mode symmetry in the grating structure has been investigated.

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Numerical Formula of Depinning Fields from Notches in Ferromagnetic Permalloy Nanowire

  • Kim, Kab-Jin;You, Chun-Yeol;Choe, Sug-Bong
    • Journal of Magnetics
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    • 제13권4호
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    • pp.136-139
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    • 2008
  • A simplified equation of depinning fields from notches of ferromagnetic Permalloy nanowires is presented. The derived equation is given in the form of an explicit function of nanowire width and thickness, and notch depth and angle. The equation agrees with all micromagnetic simulation results to an accuracy of ${\pm}$ 0.5 mT.

Evaluation of energy release rate of composites laminated with finite element method

  • Achache, Habib;Boutabout, Benali;Benzerdjeb, Abdelouahab;Ouinas, Djamel
    • Structural Engineering and Mechanics
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    • 제55권1호
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    • pp.191-204
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    • 2015
  • Control of the mechanical behavior of composite materials and structures under monotonic and dynamic loads for cracks and damage is a vast and complex area of research. The modeling of the different physical phenomena and behavior characteristics of a composite material during deformation play an important role in the structural design. Our study aims to analyze numerically the energy release rate parameter G of a composite laminated plate (glass or boron / epoxy) cross-ply [$+{\alpha}$, $-{\alpha}$] in the presence of a crack between two circular notches under the effect of several parameters such as fiber orientation ${\alpha}$, the crack orientation ${\beta}$, the orientation ${\gamma}$ of the two considered circular notches and the effect of mechanical properties. Our results show clearly that both notches orientation has more effect on G than the cracks and fibers orientations.

위상 배열 초음파 기법을 이용한 Straddle Mount형 저압 터빈 디스크 결함 평가에 관한 연구 (A Study on the Flaw Evaluation in the Straddle Mount Type Low Pressure Turbine Disc Using Phased Array Ultrasonic Technique)

  • 양승한;윤병식;김용식
    • 비파괴검사학회지
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    • 제26권4호
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    • pp.231-238
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    • 2006
  • 위상 배열 초음파 기법을 이용한 국내 표준형 윈전 저압 터빈의 디스크 검사에 대하여 연구하였다. 이를 위하여 디스크 mockup을 제작하고 결함을 가공하였으며 결함에 대한 검출과 길이 측정 방법에 따른 결과를 고찰하였다. 깊이 측정에서 릴은 결함은 AATT(absolute arrival time technique)방법 혹은 RATT (relative arrival time technique)방법을 사용하여 깊이를 측정할 수 있었으나, 조기에 발견하여야 할 깊이가 깊지 않은 결함은 이와 같은 방법으로 깊이를 측정할 수 없었다. 이 경우 결함 신호가 나타나는 각도 범위를 이용하여 결함 깊이를 측정하였으며 유용한 도구임을 확인하였다.

노치를 이용한 보강재의 부착력 증가 방안에 관한 연구 (A Study to Improve Bonding Strength with Notch in Strengthening Plate)

  • 한만엽;송병표
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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    • pp.647-652
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    • 1998
  • Recently, many strengthening methods are developed and used to rehabilitate existing structure. One of the popualr methods is the strengthening with steel plate. But steel plate have a defect that is a debondig at the end of the steel plate due to stress concentration. The objective of this paper is an experimental study for improving bonding properties of a strengthening plate. The two normally reinforced beams and ten strengthened beams steel plate, which has various notches were tested. The test results show that the notches of strengthening plate improve post-yield behavior significantly compared. It is proved that the notch in a strengthening plate increase of ulimate strength after the yield strength 9% more than ordinary strengthening method.

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V노치 또는 예리한 균열을 가지는 직사각형 평판의 굽힘 진동 (Flexural Vibrations of Rectangular Plates Having V-notches or Sharp Cracks)

  • 정희영;정의영;김주우
    • 한국소음진동공학회논문집
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    • 제14권4호
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    • pp.336-343
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    • 2004
  • This paper reports the first known free vibration data for thin rectangular plates with V-notches. The classical Ritz method is employed with two sets of admissible functions assumed for the transverse vibratory displacements. These sets include (1) mathematically complete algebraic-trigonometric polynomials which guarantee convergence to exact frequencies as sufficient terms are retained, and (2) corner functions which account for the bending moment singularities at the sharp reentrant corner of the Y-notch. Extensive convergence studies summarized herein confirm that the corner functions substantially enhance the convergence and accuracy of nondirectional frequencies for rectangular plates having the V-notch. In this paper, accurate frequencies and normalized contours of vibratory transverse displacement are presented for various notched plates, so that the effect of corner stress singularities may be understood.