• 제목/요약/키워드: initial element

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핀접합 단층래티스돔의 좌굴특성에 관한 형상초기부정의 영향 (The Effects of the Geometrically Initial Imperfection on Buckling Characteristics of pin-Jointed Single-Layer Lattice Domes)

  • 정환목
    • 한국강구조학회 논문집
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    • 제10권4호통권37호
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    • pp.769-777
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    • 1998
  • 본 연구의 목적은 삼각형네트워크를 갖는 핀접합 단층래티스돔이 형상초기부정을 가질 경우 하중상태에 따라 좌굴특성에 미치는 영향을 검토하는 것이다. 또한 형상초기부정을 고려하는 단층래티스돔의 일반화 좌굴내력식의 개발을 위한 기초자료를 수집하는데 있다. 해석은 유한요소법에 의한 이산화해석법을 이용했다.

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Probabilistic determination of initial cable forces of cable-stayed bridges under dead loads

  • Cheng, Jin;Xiao, Ru-Cheng;Jiang, Jian-Jing
    • Structural Engineering and Mechanics
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    • 제17권2호
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    • pp.267-279
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    • 2004
  • This paper presents an improved Monte Carlo simulation for the probabilistic determination of initial cable forces of cable-stayed bridges under dead loads using the response surfaces method. A response surface (i.e. a quadratic response surface without cross-terms) is used to approximate structural response. The use of the response surface eliminates the need to perform a deterministic analysis in each simulation loop. In addition, use of the response surface requires fewer simulation loops than conventional Monte Carlo simulation. Thereby, the computation time is saved significantly. The statistics (e.g. mean value, standard deviation) of the structural response are calculated through conventional Monte Carlo simulation method. By using Monte Carlo simulation, it is possible to use the existing deterministic finite element code without modifying it. Probabilistic analysis of a truss demonstrates the proposed method' efficiency and accuracy; probabilistic determination of initial cable forces of a cable-stayed bridge under dead loads verifies the method's applicability.

평면이방성 알루미늄 재료의 귀발생 예측에 있어서 항복함수와 초기 Back-Stress의 영향 (Influence of yield functions and initial back stress on the earing prediction of drawn cups for planar anisotropic aluminum alloys)

  • 윤정환;;정관수;양동열;장성기
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1998년도 춘계학술대회논문집
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    • pp.58-61
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    • 1998
  • Anisotropy is closely related to the formability of sheet metal and should be considered carefully for more realistic analysis of actual sheet metal forming operations. In order to better describe anisotropic plastic properties of aluminum alloy sheets, a planar anisotropic yield function which accounts for the anisotropy of uniaxial yield stresses and strain rate ratios simultaneously was proposed recently[1]. This yield function was used in the finite element simulations of cup drawing tests for an aluminum alloy 2008-T4. Isotropic hardening with a fixed initial back stress based on experimental tensile and compressive test results was assumed in the simulation. The computation results were in very good agreement with the experimental results. It was shown that the initial back stress as well as the yield surface shape have a large influence on the prediction of the cup height profile.

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초기양생온도에 따른 시멘트 모르터의 강도발현에 관한 기초적 연구 (A Fundamental Study on the Strength Development in Cement Mortar under Initial Curing Temperature)

  • 백민수;이영도;임남기;김성식;이종균;최문식;정상진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.157-165
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    • 1997
  • In this experiment, there is a purpose to analysis the relationship of feature of compressive strength after fixing of remarkable element under the condition of initial curing temperature. According to this experiment, we get to the fallow result. In case of highest curing temperature, 3-day-strength become high but last revelation of strength become low among the condition of initial curing temperature, the highest curing temperature have an effect on revelation of strength by the application of cumulative temperature, we can get the shape of revelation of strength.

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전통건축물에서 도리의 지붕하중 분담비율에 관한 연구 (A Research for apportionment ratio of Roof Load in Traditional Wooden Structure's Dori)

  • 황종국
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.247-250
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    • 2007
  • In korean traditional wooden structure, to know the critical pass of roof load transmission is very important. to know the critical pass of roof load transmission and to find the role of each dori members, used loading block and load cell. The total weight of loading blocks was 5,8880 N and the number of loading blocks were 16, The experimental fran1e has 1/2 scale. From middle-dori to outside-dori, the linearity of line can't guarantee. So, the distribution of roof load in dori is effected by the initial state of dori. In this research, to remove the effect of initial state, initial deformation was allowed by initial setting.

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초기균열 손상효과를 고려한 개선된 이상화 판요소 (Considerations of the Initial Crack Damage Effect on the Advanced Idealized Plate Unit)

  • 백점기;서흥원
    • 대한조선학회논문집
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    • 제31권2호
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    • pp.86-90
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    • 1994
  • 본 논문은 기존의 이상화 판요소에 초기균열 손상의 효과를 고려하여 개선된 이상화 판요소의 개발에 관한 것이다. 초기균열이 구조물의 거동에 미치는 효과를 규명하기 위해서 인장하중을 받는 판부재가 초기균열의 크기에 따른 거동을 유한요소법으로 해석하여, 그 결과를 바탕으로 기존의 이상화 판요소에 초기균열로 고려할 수 있도록 보완하였다.

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A Form-finding Technique for Three-dimensional Spatial Structures

  • Lee, Sang Jin
    • Architectural research
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    • 제15권4호
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    • pp.207-214
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    • 2013
  • A form-finding technique is proposed for three-dimensional spatial structures. Two-step discrete finite element (FE) mesh generator based on computer aided geometric design (CAGD) is introduced and used to control the shape of three-dimensional spatial structures. Mathematical programming technique is adopted to search new forms (or shapes) of spatial structures. For this purpose, the strain energy is introduced as the objective function to be minimized and the initial volume (or the initial weight) is considered as constraint function. Numerical examples are carried out to test the capability of the proposed form-finding techniques and provided as benchmark tests.

SUPERCONVERGENT GRADIENT RECOVERY FOR THE PARABOLIC INITIAL BOUNDARY VALUE PROBLEM

  • LAKHANY, AM;WHITEMAN, JR
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제3권1호
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    • pp.1-15
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    • 1999
  • Gradient recovery techniques for the second order elliptic boundary value problem are well known. In particular, the Midpoint and the Vertex Recovery Operator have been studied by various authors and under suitable assumptions on the regularity of the unknown solution superconvergence property of these recovered gradients have been proved. In this paper we extend these results to the recovered gradient of the finite element approximation to a model initial-boundary value problem, and go on to prove superconvergence result for this recovered gradient in a discrete (in time) error norm.

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스트럿-타이 모텔을 이용한 RC 휨부재의 주기적 거동에 관한 연구 (Strut-and-Tie Models for RC Flexural Members under Cyclic Loading)

  • 이수곤;홍성걸
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.453-458
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    • 2001
  • This paper presents the procedure to find the hysteresis loop of RC member using a modified strut-and-tie model. The forces and displacements at critical points, that are initial yielding point, target displacement point, unloading elastic limit, and reloading point after pinching, are investigated with the strut-and-tie models. Using bond-slip relationship, the elastic behavior of tie element is determined. The plastic flow behavior after flexural yielding is expressed by changing the location of longitudinal strut. Determination of pinching effect completes the initial hysteresis loop, assuming that the behavior of the opposite direction is symmetrical form.

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프리스트레싱 텐던의 모델링을 위한 등가하중법과 초기응력법의 비교연구 (A Comparative Study on the Equivalent Load Method and the Initial Stress Method for Modeling of the Prestressing Tendon)

  • 전세진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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    • pp.459-462
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    • 2005
  • In finite element analysis of the PSC structures, the prestressing effect can be introduced by two ways, i.e, equivalent loads or initial stress. This study investigates the reason why the two schemes that adopt the different approaches produce the similar results. The discussion is applicable to the general finite elements that correspond to the concrete and tendons. Some of the detailed derivations of each scheme are presented. Numerical examples show the identical results for the two methods.

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