• 제목/요약/키워드: Mechanical Integrity

검색결과 789건 처리시간 0.03초

Measures for the Failure Evaluation of SNF Cladding During the Transportation

  • Noh, J.S.;Kim, H.A.;Kim, T.W.
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2018년도 추계학술논문요약집
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    • pp.105-106
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    • 2018
  • It is important to set up a reasonable failure criterion for cladding, because being able to determine the cladding integrity during transportation is essential for the evaluation of SNF transportation system. There are a few of measures which can be used as a failure criterion for cladding subjected to its specific failure mode. Therefore, to select and to use appropriate failure criterion measures, i.e. strain(UE), $K_{IC}$, and CSED would be a key in evaluating the cladding integrity during transportation with every aspects. In order to justify and quantify that criterion properly, various experiments for the mechanical properties of the claddings with different conditions shall be implemented, which data will enable to justify the failure criteria proposed.

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Thermally Crosslinked Polyimide Binders for Si-alloy Anodes in Li-ion Batteries

  • Chang, Hyeong-Seok;Ji, Sang-Gu;Rho, Miso;Lee, Byoung-Min;Kim, Sung-Soo;Choi, Jae-Hak
    • Journal of Electrochemical Science and Technology
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    • 제13권3호
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    • pp.339-346
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    • 2022
  • Silicon (Si) has attracted considerable attention due to its high theoretical capacity compared to conventional graphite anode materials. However, Si-based anode materials suffer from rapid capacity loss due to mechanical failure caused by large volume change during cycling. To alleviate this phenomenon, crosslinked polymeric binders with strong interactions are highly desirable to ensure the electrode integrity. In this study, thermally crosslinked polyimide binders were used for Si-alloy anodes in Li-ion batteries. The crosslinked polyimide binder was found to have high adhesion strength, resulting in enhanced electrode integrity during cycling. Therefore, the Si-alloy anodes with crosslinked polyimide binder provide enhanced electrochemical performance, such as Coulombic efficiency, capacity retention, and cycle stability.

원자력발전소 고강도 앵커 볼트의 파괴역학적 건전성평가 (Structural Integrity Assessment of High-Strength Anchor Bolt in Nuclear Power Plant based on Fracture Mechanics Concept)

  • 임은모;허남수;심희진;오창균;김현수
    • 대한기계학회논문집A
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    • 제37권7호
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    • pp.875-881
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    • 2013
  • 증기발생기 수직 지지대를 고정하고 있는 고강도 앵커 볼트의 응력부식균열에 대한 건전성 평가는 원자력발전소 기기 건전성 유지와 관련하여 중요한 현안 가운데 하나이다. 이에 따라 미국 EPRI에서는 고강도 앵커 볼트의 건전성 평가를 위한 기준균열계수 개념 기반의 평가 절차를 제시한 바 있으며, 본 연구에서는 EPRI에서 제시한 절차에 입각하여 증기발생기 수직 지지대 고정용 앵커 볼트의 응력부식균열 및 취성 파괴에 대한 건전성 평가를 수행하였다. 이를 위해 볼트 예비하중과 운전하중을 고려한 3차원 유한요소 응력해석을 수행하여 볼트 단면에 작용하는 공칭응력을 결정하였으며, 결정된 볼트 응력과 EPRI 절차를 이용하여 앵커 볼트의 균열 건전성을 평가하였다. 또한 3차원 탄성 유한요소 파괴역학 해석을 수행하여 EPRI에서 제시한 기준균열계수의 정확성을 검증하였다.

Improvement of Surface Integrity in Hard Turning With Sensitivity Analysis of Cutting Parameter

  • Kong, Jeong-Heung;Park, Man-Jin;Kim, Jin-Hyun;Jang, Dong-Young;Han, Dong-Chul
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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    • pp.321-322
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    • 2002
  • This paper presents study of effects of cutting parameters such as cutting speed, feed rate and depth of cut on the surface roughness in hard turning. Taguchi Method and linear regression model of design parameters were utilized to identify the controlling process parameters that can monitor the surface roughness in the hard turning operation. In the process optimization, experimental planning was performed using the orthogonal array and concept of the signal-to-noise ratio. Cutting parameters such as speed, feed rate, and depth of cut were selected as process parameters and the ANOVA analysis showed that feed rate and cutting speed had more effect on the roughness variation that depth of cut.

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소듐냉각 고속로 KALIMER-600 원자로 구조 개념설계 (Structural Concept Design of KALIMER-600 Sodium Cooled Fast Reactor)

  • 이재한;박창규;김종범;구경회
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.285-290
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    • 2007
  • KALIMER-600 is a sodium cooled fast reactor with a fast spectrum neutron reactor core. The NSSS design has three heat transport systems of a PHTS (Primary Heat Transport System), a IHTS (Intermediate Heat Transport System) and a SGS (Steam Generation System). PHTS is a pool type and has a large amount of sodium in the pool. The mechanical design targets are maintaining the enough structural integrity for a seismic load of SSE 0.3g and the thermal and mechanical loads by the high temperature environments and an economical competitiveness when compared with other reactor types.

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APPLICATION OF ACOUSTIC EMISSION FOR DIAGNOSIS OF QUENCH IN SUPER CONDUCTIVE MAGNET AT CRYOGENIC TEMPERATURE

  • Lee, Joon-Hyun;Lee, Min-Rae;Kwon, Young-Kin;Song, Bong-Min
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.160-165
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    • 2007
  • It is well recently recognized that quench is one of the serious problems for the integrity of superconducting magnets, which is mainly attribute to the rapid temperature rising in the magnet due to some extrinsic factors such as conductor motion, crack initiation etc. In order to apply acoustic emission(AE) technique effectively to monitor and diagnose superconducting magnets, it is essential to identify the sources of acoustic emission. In this paper, an acoustic emission technique has been used to monitor and diagnose quenching phenomenon in racetrack shaped superconducting magnets at cryogenic environment of 4.2K. For these purposes special attention was paid to detect AE signals associated with the quench of superconducting magnets. The characteristics of AE parameters have been analyzed by correlating with quench number, winding tension of superconducting coil and charge rate by transport current.

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등온열처리법에 의해 모의 열화된 1Cr-1Mo-0.25V 터빈케이싱 강의 재질열화 평가 (Evaluation of Material Degradation of 1Cr-1Mo-0.25V Turbine Casing Steel Aged Artificially by Isothermal Heat Treatment)

  • 마영화;김도형;윤기봉
    • 한국안전학회지
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    • 제25권1호
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    • pp.22-26
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    • 2010
  • Material degradation should be considered to assess integrity and residual life of high temperature equipments. However, the property data reflecting degradation are not sufficient for practical use. In this study, mechanical properties of 1Cr-1Mo-0.25V casting steel generally used for turbine casing were measured and variation of microstructure was observed. Degradation was simulated by isothermal heat treatment.

Feature-Based Multi-Resolution Modeling of Solids Using History-Based Boolean Operations - Part II : Implementation Using a Non-Manifold Modeling System -

  • Lee Sang Hun;Lee Kyu-Yeul;Woo Yoonwhan;Lee Kang-Soo
    • Journal of Mechanical Science and Technology
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    • 제19권2호
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    • pp.558-566
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    • 2005
  • We propose a feature-based multi-resolution representation of B-rep solid models using history-based Boolean operations based on the merge-and-select algorithm. Because union and subtraction are commutative in the history-based Boolean operations, the integrity of the models at various levels of detail (LOD) is guaranteed for the reordered features regardless of whether the features are subtractive or additive. The multi-resolution solid representation proposed in this paper includes a non-manifold topological merged-set model of all feature primitives as well as a feature-modeling tree reordered consistently with a given LOD criterion. As a result, a B-rep solid model for a given LOD can be provided quickly, because the boundary of the model is evaluated without any geometric calculation and extracted from the merged set by selecting the entities contributing to the LOD model shape.

Analysis Of the Joint Structure of the Vehicle Body by Condensed Joint Matrix Method

  • Suh, Myung-Won;Yang, Won-Ho;Jonghwan Suhr
    • Journal of Mechanical Science and Technology
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    • 제15권12호
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    • pp.1639-1646
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    • 2001
  • It is often necessary that the joints characteristics should be determined in the early stage of the vehicle body design. The researches on identification of joints in a vehicle body have been performed until the recent year. In this study, the joint characteristics of vehicle structure were expressed as the condensed matrix forms from the full joint stiffness matrix. The condensed joint stiffness matrix was applied to typical T-type and Edge-type joints, and the usefulness was confirmed. In addition, it was applied to the real center pillar model and the full vehicle body in order to validate the practical application.

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Analysis of Hagen-Poiseuille Flow Using SPH

  • Min, Oakkey;Moon, Wonjoo;You, Sukbeom
    • Journal of Mechanical Science and Technology
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    • 제16권3호
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    • pp.395-402
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    • 2002
  • This paper shows how to formulate the transient analysis of 2-dimensional Hagen-Poiseuille flow using smoothed particle hydrodynamics (SPH). Treatments of viscosity, particle approximation and boundary conditions are explained. Numerical tests are calculated to examine effects caused by the number of particles, the number of particles per smoothing length, artificial viscosity and time increments for 2-dimensional Hagen-Poiseuille flow. Artificial viscosity for reducing the numerical instability directly affects the velocity of the flow, though effects of the other parameters do not produce as much effect as artificial viscosity. Numerical solutions using SPH show close agreement with the exact ones for the model flow, but SPH parameter must be chosen carefully Numerical solutions indicate that SPH is also an effective method for the analysis of 2-dimensional Hagen-Poiseuille flow.