• Title/Summary/Keyword: Cross Sectional Property

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Optical property according to the fiber cross-sectional shape (섬유단면형상에 따른 직물의 광택특성)

  • 심현주;홍경아
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2003.11a
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    • pp.171-172
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    • 2003
  • 직물의 외관 품위는 직물의 촉각뿐만 아니라 시각적인 자극에 의해서 크게 결정된다. 견직물이나 양모직물의 광택 등 자연스러운 광학적 특성은 특히 구성 섬유의 특성이나 구성사의 구조, 직물 조직 등과 밀접한 관계가 있는데 그 중 섬유단면형태가 가장 중요한 인자라고 할 수 있다. 따라서 단면형상에 따른 직물의 외관 감성 특히 시각특성에 미치는 영향을 알아보기 위하여 직물의 광택도를 측정하였다. 그 결과 섬유 단면의 요철이 많으면 광택도가 감소하면 섬유단면이 매끈한 부분이 많은 섬유는 광택도가 증가하였다. 그러나 이섬도 혼섬단면사로 구성된 직물은 광택이 우수하면서 은은함을 부여해주었다.

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Development of Drift Design Method for High-rise Buildings Considering Characteristics of Member Forces (부재력 특성을 고려한 설계변수를 사용한 고층건물 변위조절설계법 개발)

  • 서지현;박효선
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.2
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    • pp.215-222
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    • 2004
  • Drift design methods using resizing techniques have been presented as a practical drift control methods of high-rise buildings. Most drift design methods using the resizing techniques have adopted the cross-sectional area as the design variables for all structural members in a structure. However, the cross-sectional area is not always governing sectional property for the structural members, but the governing sectional property of each member is dependent on the characteristics of member forces. In this paper, a drift design method using the sectional property related to the governing displacement participation factor as the design variable of each member is presented and applied to the drift design of 20-story steel frame-shear wall system. It can be noted from example test that drift design method considering member characteristics shows similar or somewhat better results in the view point of structural weights and the accuracy of displacement estimation.

Sound Characteristics according to Cross-sectional Shapes of Fibers

  • Kim, Chunjeong;Cho, Gilsoo;Hong, Kyoung A.;Shim, Hyun Joo
    • Fibers and Polymers
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    • v.4 no.4
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    • pp.199-203
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    • 2003
  • In order to investigate the effects of cross-sectional shapes on the sound characteristics of polyester fibers, 10 specimens were woven into a twill structure made of round, hollow, triangular, u-shape, cruciform, and composite cross-sectional (▲/▲ ,()/▲, Y/Y) fibers. Their rustling sounds were recorded, and their sound spectra were obtained from FFT analysis. Physical sound parameters (LPT, ΔL, Δf) and Zwicker's psychoacoustic parameters of the loudness(Z), sharpness(Z), roughness(Z), and fluctuation strength(Z) were calculated from the sound spectra. According to noncircular cross-section fibers, the hollow shaped fiber had the highest value of LPT, ΔL, loudness(Z), and fluctuation strength(Z). The triangular shaped fiber had a lower value of LPT, ΔL, loudness(Z), and roughness(Z) than those of the round shaped fiber. Among composite cross-section fibers, C1(▲/▲) and C3 (Y/Y) had higher values of LPT, ΔL, Δf and loudness(Z) but C2(()/▲) had lower values. Also the LPT, ΔL, sharpness(Z), and roughness(Z) values of different denier were similar to each other, but the Δf and loudness(Z) values increased as the denier increased.

Determination of the Principal Directions of Composite Helicopter Rotor Blades with Arbitrary Cross Sections

  • Oh, Taek-Yul;Choi, Myung-Jin;Yu, Yong-Seok;Chae, Kyung-Duck
    • Journal of Mechanical Science and Technology
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    • v.14 no.3
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    • pp.291-297
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    • 2000
  • Modern helicopter rotor blades with non-homogeneous cross sections, composed of anisotropic material, require highly sophisticated structural analysis because of various cross sectional geometry and material properties. They may be subjected by the combined axial, bending, and torsional loading, and the dynamic and static behaviors of rotor blades are seriously influenced by the structural coupling under rotating condition. To simplify the analysis procedure using one dimensional beam model, it is necessary to determine the principal coordinate of the rotor blade. In this study, a method for the determination of the principal coordinate including elastic and shear centers is presented, based upon continuum mechanics. The scheme is verified by comparing the results with confirmed experimental results.

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Effect of Yarns Cross-Sections and Structure Parameters of Its Knitted Fabrics to Moisture Transport of Perspiration Absorption and Fast Dry Fabrics (실 단면 형상과 니트 구조 인자가 흡한속건 소재의 수분이동 특성에 미치는 영향)

  • Kim, Hyun Ah
    • Fashion & Textile Research Journal
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    • v.20 no.4
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    • pp.457-463
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    • 2018
  • This study examined the water absorption and drying properties of the thirteen types of the knitted fabrics for sports wear. These physical properties were analysed with relation to the constituent fiber cross-sectional shape and structure parameters of the knitted fabrics by regression analysis. Absorption and drying properties of the knitted fabric specimens were increased with increasing the porosity of the constituent yarns, which was attributed to the capillary channels in the yarns. The water absorption and drying properties were increased and decreased with increasing tightness factor and stitch density of the knitted fabric. The absorption property of the knitted fabric for perspiration absorption and fast dry sport-wear clothing was mostly influenced mostly by fiber cross-sectional shape and its characteristics, whereas, drying property was dependent on the structural parameters of the knitted fabric such as tightness factor and stitch density. Therefore, superior perspiration absorption and fast drying knitted fabric could be obtained in the fabric structure with optimum tightness factor and stitch density, and constituent yarn structure with non-circular fiber crosssection and high porosity. GATS method and MMT method are used to measure sweating fast drying properties and it is necessary to carry out studies using these measurement methods in order to compare with the results of this study.

The Effects of Drawing Conditions on Physical Properties of the Drawn Worsted Yarns (I) (연신공정 조건이 소모연신사의 물성에 미치는 영향 (I))

  • Han, Won-Hee;Kim, Seung-Jin;Kim, Sang-Ryong
    • Textile Coloration and Finishing
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    • v.22 no.1
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    • pp.51-60
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    • 2010
  • This research works on the effects of drawing conditions on the physical properties of the drawn worsted yarns. The drawn worsted yarns were made by the yarn drawing system under various drawing conditions such as concentration of reducing agent, draw ratio, setting time of drawn yarn, and concentration of oxidizing agent. The drawn worsted yarns from 2/80Nm to 2/90Nm were obtained from 2/60Nm worsted yarns, the surface and cross-sectional shapes and tensile properties of these various specimens were measured and discussed with the various drawing conditions. The drawing of worsted yarn made constituent wool fiber scratched and made it changing to polygonal cross-sectional shape. The tenacity and modulus were increased with draw ratio and concentration of reducing agent. And tensile strain was increased with draw ratio, which decreased with concentration of reducing agent.

Laser Processing for Manufacturing Styrofoam Pattern (주물용 스티로폼 목형 제작을 위한 레이저 가공 공정 개발)

  • 강경호;김재도
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.1085-1088
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    • 2001
  • The process of styrofoam pattern that has been used for material of press die pattern depends chiefly on handwork. Laser manufacturing system developed to increase precision and efficiency of process that is also able to convert the design easily. Applying the RP(rapid prototyping) concept reversely, the unnecessary part of section is vapored away by heat source of laser beam after converting 3-D CAD model into cross-sectional shape information. Laser beam is line-scanned in plane specimens to measure the depth and width of cut, surface roughness, cross-sectional shape as converting laser power, scanning speed, cutting gas pressure. With these basic data, plane surface, inclined surface, hole, outer contour trimming process is experimented and optimum condition are obtained. In plane and inclined surface experiments, 15W laser power and 50mm/s scanning speed make superior processing property and 30W, 10mm/s make processing efficiency increase in trimming process. With these results, simple patterns were manufactured and the possibility of applying laser manufacturing system to styrofoam pattern was convinced.

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Impedance Analysis and Experimental Study of a Solenoid Eddy Current Sensor to Detect the Cross-sectional Area of Non-ferromagnetic Stranded Conductors (비자성 연선도체의 단면적을 검출하기 위한 솔레노이드 와전류 센서의 임피던스 해석 및 실험적 연구)

  • Kim, S.D.;Shim, J.M.
    • Journal of Sensor Science and Technology
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    • v.6 no.2
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    • pp.87-94
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    • 1997
  • Impedance analysis of a Solenoid sensor to detect the cross-sectional area of non-ferromagnetic stranded conductors is described in this paper. To inspect electromagnetic characteristics of conductive materials, a nondestructive test eddy current sensor with an encircling coil is chosen. As solving Maxwell equation, normalized impedance response of the sensor within a conducting rod is modeled and the results are expanded to the stranded wires. Geometrical property affecting on stranded structure is considered and a numerical and experimental study is also presented.

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Tribological and mechanical properties of plasssma sprayed 316L and 420 stainless steel layers on the AZ91D commercial magesium alloy (AZ91D 상용 마그네슘합금위에 316L과 420의 스테인레스 스틸의 플라즈마 코팅층의 마모와 기계적 특성)

  • 이수완;박종문;이명호;짐진수
    • Journal of the Korean institute of surface engineering
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    • v.30 no.6
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    • pp.365-373
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    • 1997
  • 316L and 420 Stainless steels were deposited onto AZ9ID commercial magnesium alloy by plasma spray process with various gas flow rate of, TEX>$H_2$ secondary gas. And hardness as well as were track volume, coefficient of friction also had been measured. wear and hardness were measured by using reciprocal configuration tribometer and microghardness tester, respectively. Also, the microstructure of the coatings surface the cross sectional area of coating surface and cross sectional area of coaing/Substrate interface had been analyzed with Scanning Electron Microscope(SEM) and Optical microscope(OM). Finally, optimal process parameters for the improvement of coating efficiency such as mechanical property and wear behavior were examined.

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