• Title, Summary, Keyword: cross section analysis

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General Purpose Cross-section Analysis Program for Composite Rotor Blades

  • Park, Il-Ju;Jung, Sung-Nam;Kim, Do-Hyung;Yun, Chul-Yong
    • International Journal of Aeronautical and Space Sciences
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    • v.10 no.2
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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.

Computation of Ease-Rate in Basic Bodice Pattern by Analysis of Multiple Cross Section, Using 3-D Measuring Instrument (착의 단면 중합도 분석에 의한 길 원형의 여유률 산출 - 3차원 형상 계측기에 의한 -)

  • Shim, Kue-Nam;Kim, Jin-Sun;Lee, Womn-Ja
    • Fashion & Textile Research Journal
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    • v.2 no.4
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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.

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Estimating Ungauged River Section for Flood Stage Analysis (홍수위 해석을 위한 미측정 하천 단면 추정)

  • Shin, Sat Byeol;Kang, Moon Seong;Jun, Sang Min;Song, Jung Hun;Kim, Kyeung;Ryu, Jeong Hoon;Park, Jihoon;Lee, Do Gil;Lee, Kyeong-Do
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.5
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    • pp.11-18
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    • 2016
  • The objective of this study was to develop the simple method to estimate ungauged river section for flood stage analysis. Damage prediction should be prioritized using hydrological modeling to reduce flood risk. Mostly, the geographical data using hydrological modeling depends on national river cross-section survey. However because of the lack of measured data, it is difficult to apply to many local streams or small watersheds. For this reason, this study suggest the method to estimate unguaged river cross-section. Simple regression equations were derived and used to estimate river cross-section by analyzing the correlation between the river cross-sectional characteristics (width, height and area). The estimated cross-sections were used to simulate flood level by HEC-RAS (Hydrologic Engineering Center's River Analysis System). The applicability of this method was verified by comparing simulated flood level between measured and estimated cross-section. The water surface elevation of the flood stage analysis was 6.56-7.24 m, 5.33-5.95 m and 6.12-6.75 m for measured cross section, for estimated cross section and for estimated cross section based on DEM elevation, respectively. Further study should consider other factors for more accurate flood stage analysis. This study might be used one of the guidelines to estimate ungauged river section for flood stage analysis.

Layered Section Analysis for PSC Girder with Variable Cross Section Using SI Technique (SI기법을 이용한 변단면 PSC 거더의 층상화 단면해석)

  • Kim, Byeong Hwa;Park, Taehyo;Jeon, Hye-Kwan
    • Journal of The Korean Society of Civil Engineers
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    • v.30 no.6A
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    • pp.581-590
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    • 2010
  • This study introduces a layered sectional analysis for a PSC girder with a vaiable cross section and curved tendons. To consider the shear equilibrium at a concrete layer with curved tendons, the shear stress distribution has been computed at each section. In addition, to improve the convergence to the solution, a system identification technique is newly adopted in the solution process for strain computation. To examine the feasibility of the proposed approach, a static load test has been conducted for a full scale PSC girder with variable cross section. The prediction shows a good agreement with experiment. It is seen that a uniform cross section has the same moment capacity with a variable cross section while the variable cross section has more shear capacity than the uniform cross section. It is also noted that the maximum displacement of a variable cross section is a little smaller than a uniform cross section.

Establishment of Equi-Distance River Cross Section and Finite Element Mesh Using ArcView and Observed Cross Section (ArcView와 실측단면을 이용한 등간격 하도단면 및 유한요소망 구축)

  • Choi, Seung-Yong;Han, Kun-Yeun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.12 no.4
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    • pp.95-112
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    • 2009
  • The river cross section in the input/output data which are needed in the area of river flow analysis is very important factor. The bottom elevation of actual river cross section has to be correctly reflected to obtain correct results when two dimensional flow analysis is conducted for natural river. But to reflect virtually the bottom elevation of river cross section is impossible. The objective of this study is to suggest a method for creating equi-distance river cross section by using both HEC section and ArcView and constructing the finite element mesh. The main channels of Han and Nakdong river were selected and equi-distance river cross sections constructed in this study have shown good agreement with the observed river cross sections. In addition, high quality finite element meshes can be applied to many areas of study such as finite element analysis for water quality and two dimensional flow analysis using the suggested method for equi-distance river cross sections in this study.

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Study on the curving phenomenon of rectangular shaped product in extrusion process (사각형 단면을 가진 제품의 압출가공시 제품의 굽힘현상에 관한 연구)

  • 진인태;최재찬
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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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.

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격자무늬를 갖는 에어포일의 단면 해석 및 워핑 모형 제작

  • Chu, Hyeon-Ji;Han, Hui-Do;Kim, Nam-Jo
    • Proceeding of EDISON Challenge
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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.

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Design of Intermediate Die for Spline Drawing (스플라인형상 인발을 위한 중간패스 단면형상 설계)

  • Lee, T.K.;Lee, J.E.;Lee, S.K.;Kim, B.M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.337-340
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    • 2008
  • The cross section shape of intermediate die is one of important parameters to obtain dimensional accuracy of final product in shaped drawing process. Until now it has been designed by the experience or trial and error of the expert. In this study, the cross section shape of intermediate die fur spline shape is determined by the electronic field analysis, shape factor method. The result of the electronic field analysis, shape factor method has been compared with that of the present method. The effects of cross section shape on the dimensional accuracy were investigated by using FE analysis. And then the multi-stage shaped drawing experiments were performed to verify the results of FE analysis. As a result, the cross section shape from the electronic field analysis had the good dimensional accuracy. The electronic field analysis can be used for the method to obtain the cross section shape of intermediate die in shaped drawing process.

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Torsion of circular open cross-section with corrugated inner and outer surface

  • Pala, Yasar;Pala, Abdullah
    • Structural Engineering and Mechanics
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    • v.73 no.1
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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.

Image Analysis of the Luster of Fabrics with Modified Cross-section Fibers

  • Shin Kyung In;Kim Seong Hun;Kim Jong Jun
    • Fibers and Polymers
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    • v.6 no.1
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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.