• 제목/요약/키워드: Cross-sections

검색결과 1,472건 처리시간 0.024초

Force-deformation behaviour modelling of cracked reinforced concrete by EXCEL spreadsheets

  • Lam, Nelson;Wilson, John;Lumantarna, Elisa
    • Computers and Concrete
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    • 제8권1호
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    • pp.43-57
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    • 2011
  • Force-deformation modelling of cracked reinforced concrete is essential for a displacement-based seismic assessment of structures and can be achieved by fibre-element analysis of the cross-section of the major lateral resisting elements. The non-linear moment curvature relationship obtained from fibre-element analysis takes into account the significant effects of axial pre-compression and contributions by the longitudinal reinforcement. Whilst some specialised analysis packages possess the capability of incorporating fibre-elements into the modelling (e.g., RESPONSE 2000), implementation of the analysis on EXCEL is illustrated in this paper. The outcome of the analysis is the moment-curvature relationship of the wall cross-section, curvature at yield and at damage control limit states specified by the user. Few software platforms can compete with EXCEL in terms of its transparencies, versatility and familiarity to the computer users. The program has the capability of handling arbitrary cross-sections that are without an axis of symmetry. Application of the program is illustrated with examples of typical cross-sections of structural walls. The calculated limiting curvature for the considered cross-sections were used to construct displacement profiles up the height of the wall for comparison with the seismically induced displacement demand.

가변 롤 성형 공정시 길이방향 변형률에 근거한 제품 형상 설계 기술 개발 (Development of Profile Design Method Based on Longitudinal Strain for Flexible Roll Forming Process)

  • 주병돈;한상욱;신세계로;문영훈
    • 소성∙가공
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    • 제22권7호
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    • pp.401-406
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    • 2013
  • The use of roll-formed products increases every year due to its advantages, such as high production rates, reduced tooling cost and improved quality. However, till now, it is limited to part profiles with constant cross section. In recent years, the flexible roll forming process, which allows variable cross sections of profiles by adaptive roll stands, was developed. In this study, an attempt to optimize profile design for the flexible roll forming process was performed. An equation that predicts the longitudinal strain for part geometries with variable cross-sections was proposed. The relationship between geometrical parameters and the longitudinal strain was analyzed and investigations on the optimal profile design were performed. Experiments were conducted with a lab-scale roll forming machine to validate the proposed equation. The results show that the profile design method proposed in this study is feasible and parts with variable cross sections can be successfully fabricated with the flexible roll forming process.

A SURFACE RECONSTRUCTION METHOD FOR SCATTERED POINTS ON PARALLEL CROSS SECTIONS

  • Kim, Phil-Su
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제9권2호
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    • pp.29-43
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    • 2005
  • We consider a surface reconstruction problem from geometrical points (i.e., points given without any order) distributed on a series of smooth parallel cross sections in ${\mathbb{R}}^3$. To solve the problem, we utilize the natural points ordering method in ${\mathbb{R}}^2$, described in [18], which is a method of reconstructing a curve from a set of sample points and is based on the concept of diffusion motions of a small object from one point to the other point. With only the information of the positions of these geometrical points, we construct an acceptable surface consisting of triangular facets using a heuristic algorithm to link a pair of parallel cross-sections constructed via the natural points ordering method. We show numerical simulations for the proposed algorithm with some sets of sample points.

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MCSBEq에 의한 SF6-Ar혼합기체의 확산계수 (Diffusion Coefficients for Electrons in SF6-Ar Gas Mixtures by MCS-BEq)

  • 김상남
    • 전기학회논문지P
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    • 제64권3호
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    • pp.125-129
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    • 2015
  • Energy distribution function for electrons in SF6-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range 30~300[Td] by a two term Boltzmann equation and a Monte Carlo Simulation using a set of electron cross sections determined by other authors experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6-Ar$ mixtures were measured by time-of-flight(TOF) method, The results show that the deduced longitudinal diffusion coefficients and transverse diffusion coefficients agree reasonably well with theoretical for a rang of E/N values. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

하드디스크 드라이브의 내부 유동에 의한 액추에이터 암의 진동 저감을 위한 연구 (The Experimental Studies for Reducing Airflow-induced Vibration of Actuator Arms in HDDs)

  • 조광표;유진규;임윤철
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.670-675
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    • 2003
  • With the increase in recording density and higher rotation speeds, the aerodynamic aspect of hard disk drives (HDDs) is now quite significant. To achieve high TPI (tracks per inch) for hard disk drives, the actuator must induce less air turbulence. Also, alternative cross sections for the actuator arms are proposed for the reduction of air turbulence. In this study, off-track vibration of actuator arms used in of 3.5" hard disk drives with different cross sections have been measured by using Laser Doppler Vibrometer (LDV). It has been found that the vibration of the actuator arms with modified cross sections is lower than the conventional one.

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단면정보로부터 3차원 근사곡면의 생성 (3D Surface Approximation to Serial 2D Cross Sections)

  • 박형준;김광수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1994년도 추계학술대회 논문집
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    • pp.719-724
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    • 1994
  • This paper describes a hybrid surface-based method for smooth 3D surface approximation to a sequence of 2D cross sections. The resulting surface is a hybrid G $^{1}$ surface represented by a mesh of triangular and rectangular Bezier patches defined on skinning, branching, or capping regions. Each skinning region is approximated with a closed B_spline surface, which is transformed into a mesh of Bezier patches. Triangular G $^{1}$ surfaces are constructed over brabching and capping regions such that the transitions between each capping regions such that the transitions between each triangular surface and its neighboring skinning surfaces are G $^{1}$ continuous. Since each skinning region is represented by an approximated rectangular C $^{2}$ suface instead of an interpolated trctangular G $^{[-1000]}$ surface, the proposed method can provide more smooth surfaces and realize more efficient data reduction than triangular surfacebased method.

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3차원 공간자료 모델링 소프트웨어 개발 (3-D Spatial Data Modeling Software)

  • 이두성;김현규
    • 지구물리와물리탐사
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    • 제5권1호
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    • pp.1-5
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    • 2002
  • 본 연구에서는 2차원적으로 획득된 3차원 자료를 데이타베이스 화하고 이를 3차원적으로 분석하는데 필요한 도구인 모델링 및 시각화 소프트웨어를 ArcView환경에서 개발하였다. 본 소프트웨어는 유한개의 수평 단면으로 입력되는 자료로부터 개체의 형태를 3차원 공간상에서 구성하고 시각화한다. 프로그램은 구성된 개체로부터 임의 방향과 경사를 가진 단면을 생성할 수 있으며 단면의 수정을 통하여 해석자가 원하는 형태로 모델을 개선하는 기능을 보유하고 있다.

Determination of Inelastic Collision Cross Sections for $C_{3}F_{8}$ Molecule by Multi-term Boltzmann Equation Analysis

  • Jeon, Byung-Hoon;Ha, Sung-Chul
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.934-941
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    • 2000
  • We measured the electron transport coefficients, the electron drift velocity W and the longitudinal diffusion coefficient $D_{L}$ in the 0.526% and 5.05% $C_{3}F_{8}$-Ar mixtures over the E/N range from 0.01 Td to 100 Td by the double shutter drift tube, and compared the measured results by Hunter et al. with those. We determined the inelastic collision cross sections for the $C_{3}F_{8}$ molecule by the comparison of the present measurements and the calculation of electron transport coefficients in the $C_{3}F_{8}$-Ar mixtures by using a multi-term Boltzmann equation analysis.

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Alternative Potentials Analyzing the Scattering Cross Sections of 7,9,10,11,12,14Be Isotopes from a 12C target: Proximity Potentials

  • Aygun, M.
    • Journal of the Korean Physical Society
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    • 제73권9호
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    • pp.1255-1262
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    • 2018
  • In this paper, alternative potentials to explain the scattering cross sections of $^{7,9,10,11,12,14}Be$ isotopes by a $^{12}C$ target nucleus at different energies are researched. For this purpose, fourteen different proximity potentials, such as Proximity 1966, Proximity 1976, Proximity 1977, Proximity 1979, Proximity 1984, Proximity 1988, Proximity 1995, Broglia and Winther 1991, Aage Winther, Bass 1973, Bass 1977, Bass 1980, Christensen and Winther 1976, and $Ng{\hat{o}}$ 1980, are used to produce the real potential within the optical model. The imaginary potential is formed by using the Woods-Saxon potential. The theoretical results are compared with both experimental data and data reported in the literature. The results are in good agreement with the data. The proximity potentials are observed to play a significant role in obtaining the scattering cross sections of $^{7,9,10,11,12,14}Be$ isotopes.

Prompt Fission Neutron Spectra in Supercritical Accidents (Influence on the Fission Spectrum-averaged cross-sections of Some Threshold Activation Reactions)

  • Ro, Seung-Gy;Jun, Jae-Shik
    • Nuclear Engineering and Technology
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    • 제7권2호
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    • pp.119-126
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    • 1975
  • 핵임계 사고시에 방출되는 즉발중성자 스펙트럼을 두개의 스펙트럼 매개변수를 갖는 일반화된 Cranberg 식으로 표시할 수 있다고 가정한 다음, 이들 매개변수를 변화시키면서 몇개의 발단 방사화검출체에 대한 평균핵반응단면적의 변화를 고속전자계산기로 계산하였다. 평균핵반응 단면적은 스펙트럼 변화에 따라 민감하게 변화하는데 발단 방사화 에너지가 높을수록 그 변화정도가 심한것 같았다.

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