• Title/Summary/Keyword: Superposed Beam

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Strength Evaluation of Slender Steel Reinforced Concrete Beam-Columns

  • Chung, Jinan;Choi, Seongmo;Kim, Dongkyu
    • Architectural research
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    • v.3 no.1
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    • pp.61-70
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    • 2001
  • The paper is intended to propose design strength of slender steel reinforced beam-columns by using the modified superposed method. The design of composite members is carried out by a superposed strength method in AIJ (Architectural Institute of Japan) design method. The bearing capacities of the steel part and the concrete part have to be determined separately and then added to a combined capacity. Authors have proposed a new superposed method in a modified form for the slender composite beam-columns and reinforced column. The modified superposed method is adopted for the slender steel reinforced beam-columns. Validation of the modified superposed method is undertaken by comparison with analytical results calculated assuming a sine curve deflected shape of the beam-columns, and with the test results conducted in Japan.

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Reconfigurable Beam Steering Antenna Using Superposed Beam of Double Loops (이중 루프의 중첩 빔을 이용한 재구성 빔 조향 안테나)

  • Kim, Jae-Young;Jung, Chang-Won
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.10
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    • pp.934-940
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    • 2011
  • A novel reconfigurable beam steering antenna using double loops is proposed. The double loop antenna has a superposed beam which is produced by combining the in-phase beam in the inner loop with the out-of-phase beam in the outer loop. Also, the doble loop antenna uses two artificial switches to connect between inner loop and outer loop, and has the beam directions of three separate cases(Case 1, Case 2, Case 3) by changing ON/OFF states of switches. The operation frequency of the antenna is 14.5 GHz, and three maximum beam directions of the antenna are ${\phi}_{max}=0^{\circ}$, ${\theta}_{max}=0^{\circ}$(Case 1), ${\phi}_{max}=230^{\circ}$, ${\theta}_{max}=40^{\circ}$(Case 2) and ${\phi}_{max}=130^{\circ}$, ${\theta}_{max}=40^{\circ}$ (Case 3). The peak gains of each case are 6.5 dBi(Case 1), 7.6 dBi(Case 2) and 7.8 dBi(Case 3). The half power beam width(HPBW) of each case is $86{\sim}104^{\circ}$, and the overall HPBW is $160^{\circ}$.

Surface Encoding Method Based on the Superposed Pattern (적층 패턴 기반의 서피스 인코딩 방법)

  • Jung, Kwang-Suk;Park, Sung-Jun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.1
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    • pp.58-64
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    • 2012
  • Instead of the surface pattern arranged repeatedly in two axial direction on a plane, we propose double patterns superposing two one-axial linear patterns as a reference target for surface encoding. A upper layer of the superposed pattern is the transparent glass with grooves cut in it at a fixed pitch. The position is sensed by detecting a shift of beam due to difference of a refractive index. And a lower layer is the aluminum with color-coated grooves. The amount of beam reflected on the layer varies according to its targeting position and is detected for encoding. For the above reference pattern, we can detect two-axial positions using only the single beam. Furthermore, the pattern size can be expanded with a size of the detector kept constant, meaning that the measured range can be expanded easily. In this paper, we review the existing optical encoding methods for grid pattern, and discuss the hardware implementation of the suggested surface encoding method.

Use of homogenization theory to build a beam element with thermo-mechanical microscale properties

  • Schrefler, B.A.;Lefik, M.
    • Structural Engineering and Mechanics
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    • v.4 no.6
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    • pp.613-630
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    • 1996
  • The homogenization method is used to develop a beam element in space for thermo-mechanical analysis of unidirectional composites. Local stress and temperature field in the microscale are described using the function of homogenization. The global (macroscopic) behaviour of the structure is supposed to be that of a beam. Beam-type kinematical hypotheses (including independent shear rotations) are hence applied and superposed on the microdescription. A macroscopic stiffness matrix for such a beam element is then developed which contains the microscale properties of the single cell of periodicity. The presented model enables us to analyse without too much computational effort complicated composite structures such as e.g. toroidal coils of a fusion reactor. We need only a FE mesh sufficiently fine for a correct description of the local geometry of a single cell and a few of the newly developed elements for the description of the global behaviour. An unsmearing procedure gives the stress and temperature field in the different materials of a single cell.

Analysis of Thermal Relaxation Time of Tissues Subject to Pulsed Laser Irradiation (초단파 레이저 조사시 티슈 열완화 시간 분석)

  • Kim, Kyung-Han;Lee, Jae-Hoon;Suh, Jeong
    • Laser Solutions
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    • v.12 no.2
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    • pp.17-25
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    • 2009
  • Two methodologies for predicting thermal relaxation time of tissue subjected to pulsed laser irradiation is introduced by the calculation the optical penetration depth and by the investigation of the temperature diffusion behavior. First approach is that both x-axial and y-axial thermal relaxation times are predicted and they are superposed to achieve the thermal relaxation time (${\tau}_1$) for two-dimensional square tissue model. Another approach to achieve thermal relaxation time (${\tau}_2$) is measuring the time required for local temperature drop until $e^{-1}$ of the maximum laser induced heating.

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Static deflection of nonlocal Euler Bernoulli and Timoshenko beams by Castigliano's theorem

  • Devnath, Indronil;Islam, Mohammad Nazmul;Siddique, Minhaj Uddin Mahmood;Tounsi, Abdelouahed
    • Advances in nano research
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    • v.12 no.2
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    • pp.139-150
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    • 2022
  • This paper presents sets of explicit analytical equations that compute the static displacements of nanobeams by adopting the nonlocal elasticity theory of Eringen within the framework of Euler Bernoulli and Timoshenko beam theories. Castigliano's theorem is applied to an equivalent Virtual Local Beam (VLB) made up of linear elastic material to compute the displacements. The first derivative of the complementary energy of the VLB with respect to a virtual point load provides displacements. The displacements of the VLB are assumed equal to those of the nonlocal beam if nonlocal effects are superposed as additional stress resultants on the VLB. The illustrative equations of displacements are relevant to a few types of loadings combined with a few common boundary conditions. Several equations of displacements, thus derived, matched precisely in similar cases with the equations obtained by other analytical methods found in the literature. Furthermore, magnitudes of maximum displacements are also in excellent agreement with those computed by other numerical methods. These validated the superposition of nonlocal effects on the VLB and the accuracy of the derived equations.

General Response for Lateral-Torsional Buckling of Short I-Beams Under Repeated Loadings (반복하중을 받는 짧은 I형 보의 횡-비틀림 좌굴의 일반적 응답에 관한 고찰)

  • 이상갑
    • Computational Structural Engineering
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    • v.5 no.1
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    • pp.119-132
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    • 1992
  • The objective of this study is to perform extensive parametric studies of the lateral-torsional buckling of short 1-beams under repeated loadings, and to gain a further insight into the lateral-torsional beam buckling problem. A one-dimensional geometrically (fully) nonlinear beam model is used, which includes superposed infinitesimal transverse warping deformation in addition to finite torsional warping deformation. A multiaxial cyclic plasticity model is also implemented to better represent cyclic metal plasticity in conjunction with a consistent return mapping algorithm. The general response for the lateral-torsional buckling of short I-beams under repeated loadings is examined through several parametric studies around the standard case : the material yield strength, the yield plateau, the strain hardening, the kinematic hardening, the residual stresses, the load eccentricity with respect to the shear center, the height of the load with respect to the cross-section of the beam, the location of the load along the length of the beam, the dimensions of the cross-section of the beam and the fixity of the supported end remote from the load.

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A Study of the Phase Relations Between the Reflected and Transmitted Light Waves at a Beam Splitter and Their Application to Interferometers (빔가르개에서 반사광과 투과광 사이의 위상 관계 고찰 및 간섭계 적용)

  • Son, Byungwoo;Choi, Hee Joo;Park, Ju Eun;Cha, Myoungsik
    • Korean Journal of Optics and Photonics
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    • v.26 no.2
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    • pp.103-109
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    • 2015
  • In an amplitude-splitting interferometer, a beam splitter divides an input beam into two parts, which are superposed after propagating along separate paths, producing an interference effect. We have investigated the phase relation between the reflected and transmitted light waves at BS's made of lossless dielectric stacks. If we define the phases with proper reference planes, a definite phase relation exists, irrespective of the detailed structure of the layers in the BS. Although this results from the generalized Stokes relations, we have verified it numerically for two representative BS's with symmetric and asymmetric layer structures respectively. When we applied the phase relation to interferometers, we could determine the superposition state of the output beam (either constructive or destructive interference) for a general BS, and could verify that the light's energy was conserved.

Measuring Method of Planar Displacement Referring to The Double Linear Patterns (이중화된 패턴을 참조하는 평면 변위 측정 방법)

  • Park, Sung Jun;Jung, Kwang Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4405-4410
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    • 2015
  • Two-dimensional displacements are obtained from the sandwiched patterns, which superpose two linearly-periodic patterns orthogonally, respectively. The transparent top pattern is identified by deflection of the laser beam due to a difference of refractivity and the opaque bottom pattern is identified by deviation of the beam intensity due to a difference of reflectance. In the sample setup, the top pattern made up of build-up film is manufactured by UV laser machining and the bottom pattern is manufactured by ultra-precision trench machining and deposition for aluminum plate. The proposed decoding method is verified experimentally using the $10{\mu}m$ equally spaced sample patterns and the devised optical system. The Korea Academia-Industrial cooperation Society.

Analysis of composite steel-concrete beams using a refined high-order beam theory

  • Lezgy-Nazargah, M.;Kafi, L.
    • Steel and Composite Structures
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    • v.18 no.6
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    • pp.1353-1368
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    • 2015
  • A finite element model is presented for the analysis of composite steel-concrete beams based on a refined high-order theory. The employed theory satisfies all the kinematic and stress continuity conditions at the layer interfaces and considers effects of the transverse normal stress and transverse flexibility. The global displacement components, described by polynomial or combinations of polynomial and exponential expressions, are superposed on local ones chosen based on the layerwise or discrete-layer concepts. The present finite model does not need the incorporating any shear correction factor. Moreover, in the present $C^1$-continuous finite element model, the number of unknowns is independent of the number of layers. The proposed finite element model is validated by comparing the present results with those obtained from the three-dimensional (3D) finite element analysis. In addition to correctly predicting the distribution of all stress components of the composite steel-concrete beams, the proposed finite element model is computationally economic.