• Title/Summary/Keyword: cross-sections

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

  • Lam, Nelson;Wilson, John;Lumantarna, Elisa
    • Computers and Concrete
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    • v.8 no.1
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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.

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

  • Joo, B.D.;Han, S.W.;Shin, S.G.R.;Moon, Y.H.
    • Transactions of Materials Processing
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    • v.22 no.7
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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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    • v.9 no.2
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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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Diffusion Coefficients for Electrons in SF6-Ar Gas Mixtures by MCS-BEq (MCSBEq에 의한 SF6-Ar혼합기체의 확산계수)

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.64 no.3
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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.

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

  • Cho, Kwang-Pyo;Yoo, Jin-Gyoo;Rhim, Yoon-Chul
    • Proceedings of the KSME Conference
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    • 2003.11a
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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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3D Surface Approximation to Serial 2D Cross Sections (단면정보로부터 3차원 근사곡면의 생성)

  • 박형준;김광수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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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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3-D Spatial Data Modeling Software (3차원 공간자료 모델링 소프트웨어 개발)

  • Lee, Doo-Sung;Kim, Hyoun-Gyu
    • Geophysics and Geophysical Exploration
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    • v.5 no.1
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    • pp.1-5
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    • 2002
  • We developed a modeling and visualization software that can analyze 3-dimensional spatial information in the ArcView environment. The software constructs and visualizes an object in 3 dimensional space from the input data given a number of horizontal cross-sections. The software can generate and visualize the cross-sections of the object in any azimuth and inclination. Utilizing the program users can modify the 3-D shape of the object by interactively editing the cross-sections.

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

  • Jeon, Byung-Hoon;Ha, Sung-Chul
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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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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    • v.73 no.9
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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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    • v.7 no.2
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    • pp.119-126
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    • 1975
  • On the assumption that the spectral distribution of prompt fission neutrons released from supercritical accidents can be expressed by the generalized Cranberg form with two spectral parameters, which is then transformed into the single parameter form, a variation of the fission spectrum-averaged cross-sections for some threshold reactions with varying the spectral parameter has teen calculated using an electronic computer. It appears that the average cross-sections are very sensitive to the spectral deformation, especially those for the detectors having the threshold at high neutron energy are high compared to those for the detectors of which the threshold energies are comparatively low.

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