• 대한토목학회논문집
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• 제30권6A호
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• pp.581-590
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• 2010

본 연구는 곡선배치 텐던을 갖는 변단면 PSC의 전단을 고려한 층상화 단면해석기술을 소개한다. 곡선배치 텐던의 전단평형을 고려하기 위해서, 각 층상화 단면에서 전단응력을 직접 산출 할 수 있는 새로운 방법과 각 층상화 단면의 변형률 산정시 기존의 반복법보다 수렴 속도가 효율적인 시스템인식기법을 적용하였다. 제안기법은 변단면 PSC보의 정재하실험 결과와 비교분석 되었으며, 추정된 구조응답과 실험결과가 잘 일치하고 있다. 또한, 동일 조건에서 변단면 PSC보와 균등단면 PSC보의 거동특성이 비교분석되었다. 분석결과을 살펴보면, 휨강성은 변단면과 균등단면이 동일하지만, 전단강성은 변단면이 균등단면 보다 크다. 더욱이, 변단면의 자중이 균등단면보다 크지만 변단면의 최대처짐이 균등단면 보다 작다.

• 한국지리정보학회지
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• 제12권4호
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• pp.95-112
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• 2009

하천의 흐름해석 분야에서 모형이 요구하는 입력자료 중 하천단면은 매우 중요한 요소이다. 수치모형을 이용해서 자연하천의 2차원 흐름을 모의하고자 할 때 정확한 계산치를 얻기 위해서는 실제 하천단면의 하상을 정확하게 반영하여야 한다. 그러나 하천단면의 하상을 실제 상태의 모습 그대로 반영하는 것은 거의 불가능하다. 본 연구에서는 현재 실무에서 사용하는 하천측량 자료인 HEC단면과 ArcView를 연계하여 등간격 하도단면을 생성하고 유한요소망을 구축하는 방법을 제안하였다. 연구 대상지역은 한강 본류 구간과 낙동강 본류 구간을 선정하였고 등간격 하도단면 구축결과 실측 단면자료와 잘 일치함을 확인할 수 있었다. 또한 본 연구에서 제안한 등간격 하도단면을 이용하면 2차원 흐름해석 및 수질해석을 위한 양질의 유한요소망을 구축하여 유한요소해석 등에 유용하게 사용될 수 있을 것이다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 추계학술대회논문집
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• pp.7-13
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• 1996

The kinematically admissible velocity field is developed for the analysis of extruded products. The curving of product in extrusion is caused by the linearly distributed longitudinal velocity on the cross-section of the workpiece at the die exit. In the analysis, the longitudinal velocity in extrusion direction is divided into the uniform velocity and the deviated velocity. In order to satisfy the requrement of the kinematically admissible velocity field, the average value of the deviated velocity should be zero. At the same time, it should linearly change with the distance form the center of gravity of the cross-section of the workpiece. The results of the analysis show that the curvature of product increses with increses in eccentricity of gravity center of the cross-section of workpiece at die entrance form that of the cross-section at the die exit. In the analysis, the longitudinal velocity in extrusion direction is divided into the uniform velocity and the deviated velocity. In order to satisfy the requrement of the kinematically admissible velocity field, the average value of the deviated velocity should be zero. At the same time, it should linearly change with the distance from the center of gravity of the cross-section of the workpiece. The results of the analysis show that the curvature of product increses with increses in ecentricity of gravity center of the cross-section of workpiece at die entrance from that of the cross-section at the die exit.

• EDISON SW 활용 경진대회 논문집
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• 제4회(2015년)
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• pp.257-262
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• 2015

In this paper, the cross-section properties of thin-walled beam are calculated through KSec2D in consist of Saint-Venant theory. To investigate tendency increasing the thickness, we analysis cross-section using isotropic material. In the asymmetric cross-section, we investigate effect caused cross-section properties accompanied increasing the thickness. The structural properties such as bending stiffness, tosion stiffness per area of each cross-section in three cases is compared through increasing thickness. The warping displacement calculated by KSed2D is modeled by CATIA. In order to show that warping influence the cross-section, the warping shape modeled CATIA is printed 3D printer.

• International Journal of Aeronautical and Space Sciences
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• 제10권2호
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• pp.77-85
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• 2009

A two-dimensional cross-section analysis program based on the finite element method has been developed for composite blades with arbitrary cross-section profiles and material distributions. The modulus weighted approach is used to take into account the non-homogeneous material characteristics of advanced blades. The CLPT (Classical Lamination Plate Theory) is applied to obtain the effective moduli of the composite laminate. The location of shear center for any given cross-sections are determined according to the Trefftz' definition while the torsion constants are obtained using the St. Venant torsion theory. A series of benchmark examples for beams with various cross-sections are illustrated to show the accuracy of the developed cross-section analysis program. The cross section cases include thin-walled C-channel, I-beam, single-cell box, NACA0012 airfoil, and KARI small-scale blades. Overall, a reasonable correlation is obtained in comparison with experiments or finite element analysis results.

• Structural Engineering and Mechanics
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• 제73권1호
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• pp.75-82
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• 2020

In this study, the problem of torsion of bars with open cross section surrounded by corrugated boundaries is analyzed. An approximate analytical solution is given using perturbation technique. First, the stress analysis for circular open cross-section for arbitrary opening angle is formulated and the problem is analytically solved. Second, the open cross-section with corrugated cross section is analyzed using perturbation method. First order contributions to the stresses and the torques have been added. The results have been exemplified and compared by considering special examples.

• Fibers and Polymers
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• 제6권1호
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• pp.82-88
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• 2005

We have investigated the luster of modified cross-sectional fiber fabrics as one of the essential quality estimates for clothing development. We have confirmed an objective evaluation method, and have determined the experimental luster char­acteristics of modified cross-section fibers. The cross-section of the fibers in a fabric affects the appearance of a textile. We used the image analysis method to investigate the luster to determine the critical factors influencing the appearance of modi­fied cross-section fiber fabrics. For similarly structured textiles in a component fabric, clear differences were observed in the fabric weave, density, percentage, and total area of blobs, which is image region. Color played a decisive role in the luster of the textiles, and luster was not significantly influenced by the modified cross-section fabric weave. In addition, the degree of luster did not increase in the order plain to twill to satin for modified cross-sectional fiber fabrics. All the split-type microfi­bers exhibited higher numerical luster values (percentage of pixels, and number and total area of blobs) than sea-island microfibers did. The degree of luster of the modified cross-sectional fiber fabrics was not high at specular reflection angles.

• 한국의류산업학회지
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• 제2권4호
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• pp.360-365
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• 2000

This research is the trial for the computation of the ease-rate for the bodice pattern. The result of the analysis about the cross section figures of garment space by using a 3-D measuring instrument is that: The garment space of each bodice by each body size is definite. In the figure of cross section of the basic lines, an area of cross section of garment space and length of cross section of garment space are not increased in proportion to an area of cross section of the body. The ease rate is the same no matter that flat-rate of the body is same or different. The ease-rate is computed by length of cross section of garment space that is in proportion to the radius of the body.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.862-870
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• 2010

This thesis has been researched on optimized design method for the total cross section of embankment considering the fact that the size of embankment cross section is directly related with economic efficiency when dam designing. In general, embankment cross section of fill dam is either determined by cohesion and angle of internal friction, a strength parameter of embankment materials or by permeability of embankment. Therefore the size of embankment cross section depending on strength parameter of embankment materials was determined by using MIDAS-GTS program through stress-seepage coupled analysis at the time of fill dam design. As a result, determination of embankment cross section was more affected by the size of central core and permeability rather than by slope stability by shear strength and it was revealed that in case of embankment height being over 20m, stability against infiltration and slope action could be secured only when embankment slope is at least over 1:2.5. In addition, it was also revealed that in case of making the size of central core exceeding specification standard, total cross section of embankment could be reduced considerably and at the time of embankment design, adequate size and appropriateness of embankment cross section could be determined with referring the table suggested by this study.

• 한국군사과학기술학회지
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• 제10권3호
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• pp.16-24
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• 2007

The high-frequency analysis method of back-scattering cross section spectrum of rotating targets is established. The time history of the back-scattering cross section is calculated using a quasi-stationary approach, based on a physical optics and a physical theory of diffraction, combining an adaptive triangular beam method to consider the shadow effect. And the spectra of back-scattering cross section by the Doppler effect are analyzed applying a simple fast Fourier transform method to its time history. The numerical calculation for rotating targets, such as rotating metal plates and underwater propeller, are carried out. The time history appears to be periodic with respect to the number of wings. The backscattering cross section spectrum level and its frequency shift are dependent on the rotating speed, direction, and the shape of the targets.