• 제목/요약/키워드: Computational Mechanics

검색결과 737건 처리시간 0.023초

균열 쉘의 파기역학해석을 위한 선진유한요소기법 (Advanced Finite Element Technology for Fracture Mechanics Analysis of Cracked Shells)

  • 우광성
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1990년도 가을 학술발표회 논문집
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    • pp.3-8
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    • 1990
  • A new finite element technology based on p-version of F.E.M. is discussed with reference to its potential for application to stress intensity factor computations. In linear elastic fracture mechanics, especially cracked cylindrical shells. It is shown that the p-version nutlet is far better suited for computing the stress intensity factors than the conventional h-version models with the help of three test problems. The main advantage of this technology is that the accuracy of approximation can be established without mesh refinement or the use of special procedures.

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Aha, CST and CFD !

  • 김승조;김민기;문종근
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2009년 춘계학술대회논문집
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    • pp.9-18
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    • 2009
  • This paper presents the state of the art of computational structures technology(CST) and comparison of two computational mechanics - CST and CFD, to the CFD engineers. Classical mechanics is based on the five classical axioms which describe the motion and behaviors of the continuum materials like solid structures and fluids. Computational structures technology uses the finite element method to solve the governing equation, whereas finite volume method is generally used in CFD. A few famous commercial structural analysis programs and DIAMOND/IPSAP will be introduced. DIAMOND/IPSAP is the efficient parallel structural analysis package developed by our research team. DIAMOND/IPSAP shows the better performance than the commercial structural analysis software not only in the parallel computing environments but also in a single computer.

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초장대현수교(광양대교)의 실현을 위한 교량구조시스템의 혁신 (Innovation of Bridge Structural Systems to Realize a Super Long-span Suspension Bridge (Gwangyang Bridge))

  • 김홍식;권호철;송명관;백종균
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.551-556
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    • 2007
  • In this paper, the contents of numerical in the innovative tender design of the super long-span suspension bridge to be constructed between Myodo and are introduced. The total span length of the bridge, of which the main span is the third in the world so far, reaches 2,260km, and the has the floating type girder which has no vertical points at pylon. Judging from the condition of navigation, wind climate on, and construction cost, it is inevitable to make the central span 1,545m and to the technical level applied to the structural components in the existing suspension system. To realize the innovative super long-span suspension bridge, the close numerical investigations for the structural capacity, aerodynamic serviceability, and dynamic serviceability are carried out by various tools of computational mechanics.

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피니싱 툴 유니트의 에어 임펠러 설계에 관한 연구 (A Study on the Design for the Air Impeller of a Finishing Tool Unit)

  • 최현진;강익수;이승용;장은실;박선명;최성대
    • 한국CDE학회논문집
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    • 제20권3호
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    • pp.312-319
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    • 2015
  • The grinding and furbishing process as the finishing process for molds include the works such as the grinding, buffing, lapping and polishing among others. A finishing tool unit is applied to this finishing process for the burr, lapping, polishing and others of molds. A finishing tool unit can carry out the flexible machining, depending on the machining allowance for objects to be cut on the basis of the instrumental driving mechanism which enables the up, down, left and right floating, which is applied in link with the dedicated cutters and robot machining systems. This study selected the shape to increase the rotatory force of an impeller when air is discharged during the driving of a finishing tool unit, and reflected it to the impeller designing. In addition, the study analyzed each flow velocity and pressure distribution per air pressurization value and finally analyzed the rotating torque to suggest the optimal conditions in designing impellers.

Modelling of effective irradiation swelling for inert matrix fuels

  • Zhang, Jing;Wang, Haoyu;Wei, Hongyang;Zhang, Jingyu;Tang, Changbing;Lu, Chuan;Huang, Chunlan;Ding, Shurong;Li, Yuanming
    • Nuclear Engineering and Technology
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    • 제53권8호
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    • pp.2616-2628
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    • 2021
  • The results of effective irradiation swelling in a wide range of burnup levels are numerically obtained for an inert matrix fuel, which are verified with DART model. The fission gas swelling of fuel particles is calculated with a mechanistic model, which depends on the external hydrostatic pressure. Additionally, irradiation and thermal creep effects are included in the inert matrix. The effects of matrix creep strains, external hydrostatic pressure and temperature on the effective irradiation swelling are investigated. The research results indicate that (1) the above effects are coupled with each other; (2) the matrix creep effects at high temperatures should be involved; and (3) ranged from 0 to 300 MPa, a remarkable dependence of external hydrostatic pressure can be found. Furthermore, an explicit multi-variable mathematic model is established for the effective irradiation swelling, as a function of particle volume fraction, temperature, external hydrostatic pressure and fuel particle fission density, which can well reproduce the finite element results. The mathematic model for the current volume fraction of fuel particles can help establish other effective performance models.

Three-dimensional numerical simulation of hydrogen-induced multi-field coupling behavior in cracked zircaloy cladding tubes

  • Xia, Zhongjia;Wang, Bingzhong;Zhang, Jingyu;Ding, Shurong;Chen, Liang;Pang, Hua;Song, Xiaoming
    • Nuclear Engineering and Technology
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    • 제51권1호
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    • pp.238-248
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    • 2019
  • In the high-temperature and high-pressure irradiation environments, the multi-field coupling processes of hydrogen diffusion, hydride precipitation and mechanical deformation in Zircaloy cladding tubes occur. To simulate this hydrogen-induced complex behavior, a multi-field coupling method is developed, with the irradiation hardening effects and hydride-precipitation-induced expansion and hardening effects involved in the mechanical constitutive relation. The out-pile tests for a cracked cladding tube after irradiation are simulated, and the numerical results of the multi-fields at different temperatures are obtained and analyzed. The results indicate that: (1) the hydrostatic stress gradient is the fundamental factor to activate the hydrogen-induced multi-field coupling behavior excluding the temperature gradient; (2) in the local crack-tip region, hydrides will precipitate faster at the considered higher temperatures, which can be fundamentally attributed to the sensitivity of TSSP and hydrogen diffusion coefficient to temperature. The mechanism is partly explained for the enlarged velocity values of delayed hydride cracking (DHC) at high temperatures before crack arrest. This work lays a foundation for the future research on DHC.