• 제목/요약/키워드: Short fiber

검색결과 678건 처리시간 0.019초

옹벽 배면토체 적용을 위한 단섬유 보강토의 전단강도 특성 (Shear Strength Characteristics of Short-fiber Reinforced Soil for the Application of Retaining Wall Backfill)

  • 박영곤;차경섭;장병욱
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2003년도 추계학술대회 논문집(II)
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    • pp.73-78
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    • 2003
  • As a fundamental study to develop the retaining wall of new type, short-fibers are mixed with soils and a series of compaction tests and triaxial compression tests for short-fiber reinforced soils are performed. From the results of compaction tests, optimum moisture content is increased and maximum dry unit weight is decreased with fiber mixing ratio. When 60mm fibrillated fiber of 0.2$\%$ mixing ratio is added to SM soil, strength increment of short-fiber reinforced soil is above 1.2 times compared to soil only. Strength increment shows maximum value for composite reinforced soil, namely, soil+short-fiber+planar reinforcement. But in case of mixing with ML soil and short-fiber, the strength of short-fiber reinforced soil is nearly the same as soil only. Internal angle of short-fiber reinforced soil is increased about $2\~3$ degrees and cohesion is also increased above 10kPa compared to soil only. Therefore, it is judged that short-fiber is a good material to strengthen the soil.

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재성형된 단섬유 보강점토의 구성과 보강효과 (Composition and Peinforcing Effect of Remolded Short Fiber Reinforced Clay)

  • 박영곤;장병욱
    • 한국지반공학회논문집
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    • 제16권6호
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    • pp.87-95
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    • 2000
  • A series of consolidated undrained triaxial compression testes were performed to increase field applications of soil admixtures mixed with short fiber. Kaolin clay and three types of fiber were selected and auto cutter was used to obtain reliable length of fibers. Remolded soil specimens were tested for obtaining the basic data to be applied to the reinforcement of soft clay, embankment or barrier and clay liner of wastes landfill etc. Conversion equations from weight to volume of clay mixed with short fiber are introduced and relationships between fiber content and fiber concentration are derived. It is found that reinforcing effect by aspect ratio and mixing ratio of short fiber decreases as confining pressure increases. The best efficient reinforcing effect is given at the aspect ratio of 80~120 and the fiber content of 1.2%~2.4% and the fiber diameter of 0.27mm.

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단섬유 끝 형상이 강화고무의 인장 특성에 미치는 영향 (Effects of Short-fiber End Shape on Tensile Properties of Reinforced Rubber)

  • 류상렬;이동주
    • 대한기계학회논문집A
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    • 제25권6호
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    • pp.1023-1030
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    • 2001
  • The tensile properties of short nylon6 fiber reinforced NR and SBR have been investigated as functions of diameter ratio(DR), interphase condition, fiber aspect ratio(AR), and fiber content. The short-fiber(DR=3 and AR=2) reinforced SBR did not show the dilution effect for all interphase conditions. And the short-fiber(DR=3 and AR=2) reinforced NR did not show the dilution effect except for the no-coating. The better interphase condition, the lower dilution effect at same DR. The tensile moduli are significantly improved due to fiber content and diameter ratio at same interphase condition. The pull-out force increased with the DR. The better interphase condition, the higher pull-out force at same DR. It is found that the DR and AR have an important effect on tensile properties.

각종 단섬유펄프를 이용한 화선지 제조 (Manufacture of Hwaseonji(Korean Traditional Paper) Using Various Kinds of Short-Length Fiber Pulps)

  • 강진하;주용찬
    • 펄프종이기술
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    • 제37권2호
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    • pp.78-86
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    • 2005
  • Hwaseonji(Korean traditional paper) used for writing and painting has been made from the mulberry bast-fiber and the short-length fiber pulps, wood pulps. However, besides wood pulps, other short-length fiber pulps also can be used instead of wood pulps. Hence, this research was carried out to make the various Hwaseonjis with the different properties, using the five kinds of short-length fiber pulps respectively. The short-length fiber pulps used in this research were softwood bleached kraft pulp(SwBKP) hardwood bleached kraft pulp(HwBKP), rice-straw bleached sulfite pulp(RsBSP), bamboo bleached kraft pulp(BbBKP) and recycled pulp from vellem paper(RP). And, the mixture ratios of the mulberry bast-fiber pulp and short-length fiber pulps were 100:0, 80:20, 60:40, 40:60 and 20:80. After various Hwaseonjis were made from different mixtures mentioned above with hand-made method, physical properties and chinese ink blot property of each paper were measured. The strengthes were the highest in the Hwaseonji made from the mixture of the mulberry bast-fiber pulp and SwBKP. However, chinese ink blot property and smoothness were better when RsBSP, BbBKP or RP were mixed into the mulberry bast-fiber pulp. As a result, the various kinds of Hwaseonjis which the users can choose based on their needs were made.

Synergistic effect of clay and polypropylene short fibers in epoxy based ternary composite hybrids

  • Prabhu, T. Niranjana;Demappa, T.;Harish, V.;Prashantha, K.
    • Advances in materials Research
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    • 제4권2호
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    • pp.97-111
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    • 2015
  • Polypropylene short fiber (PP)-clay particulate-epoxy ternary composites were prepared by reinforcing PP short fiber and clay particles in the range of 0.1 phr to 0.7 phr into epoxy resin. Prepared hybrid composites were characterized for their mechanical, thermal and flame retardant properties. The obtained results indicated an increase in impact resistance, tensile strength, flexural strength and Young's modulus to an extent (up to 0.5 phr clay and 0.5 phr PP short fiber) and then decreases as the reinforcing phases are further increased. The thermal stability of these materials are found to increase up to 0.2 phr clay and 0.2 phr PP addition, beyond which it is decreased. Addition of clay is found to have the negative effect on epoxy-PP short fiber composites, which is evident from the comparison of mechanical and thermal properties of epoxy-0.5 phr PP short fiber composite and epoxy-0.5 phr PP short fiber-0.5 phr clay composite hybrid. UL-94 tests conducted on the composite hybrids have showed a reduction in the burning rate. Morphological observations indicated a greater fiber pull with the addition of clay. The performed tests in the present study indicated that materials under investigation have promising applications in construction, agriculture and decorative purposes.

단섬유강화 복합재료에서 사출측/금형측 노즐 크기 변화에 따른 섬유손상 및 기계적 성질 (The Fiber Damage and Mechanical Properties of Short-fiber Reinforced Composite Depending on Nozzle Size Variations in Injection/Mold Sides)

  • 이인섭;이동주
    • 대한기계학회논문집A
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    • 제25권4호
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    • pp.564-573
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    • 2001
  • The mechanical properties of short carbon/glass fiber reinforced polypropylene are experimentally measured as functions of fiber content and nozzle diameter. Also, these properties are compared with the survival rate of reinforced fibers and fiber volume fraction using image analysis after pyrolytic decomposition. The survival rate of fiber aspect ratio as well as fiber volume fraction is influenced by injection processing condition, the used materials and mold conditions such as diameter of nozzle, etc. In this study, the survival rate of fiber aspect ratio is investigated by nozzle size variations in injection/mold sides. It is found that the survival rate of glass fiber is higher that the survival rate of glass fiber is higher than that of carbon fiber. Both tensile modulus and strength of short-fiber reinforced polypropylene are improved s the fiber volume fraction and nozzle diameter are increased.

다양한 섬유재료를 이용한 화선지의 제조와 그 특성 (Manufacture of Oriental Painting Paper (Hwaseonji) Using Various Kinds of Plant Fibers)

  • 문성필;최영재;강석근
    • 펄프종이기술
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    • 제35권3호
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    • pp.79-84
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    • 2003
  • Oriental painting paper (Hwaseonji) was prepared from various kinds of plant fibers and its physical properties were investigated. The fibers used were classified into three different length of fibers; long fiber (<1.8 mm), medium fiber (1.4-1.8 mm) and short fiber (>1.4 mm). The fibers were mixed in the ratio of 15% long fiber, 25% medium fiber and 60% short fiber. The Hwaseonji prepared from mixing of the bamboo or rice straw pulp as a short fiber with the long and medium fibers showed excellent physical properties with a high smoothness and uniformity of Chinese ink blot. Mixing with LBKP as a short fiber was resulted in low physical properties, smoothness and wide ink blot. The properties of Hwaseonji, such as ink absorption, roughness and smoothness, may be predicted from the correlation of density with Chinese ink blot and smoothness.

일방향으로 배열된 단섬유 보강 복합재료의 탄성률 예측 (Prediction of Elastic Modulus of Unidirectional Short Fiber Composite Materials)

  • 임태원;권영두;한경섭
    • 대한기계학회논문집
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    • 제14권2호
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    • pp.407-412
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    • 1990
  • Elastic modulus of unidirectional short fiber composite has theoretically derived with the consideration of Poisson's ratios of matrix and fiber. Unidirectional short fiber composite is modeled as an aggregate of grains developed by Kerner. Under the assumption of extra strain at fiber ends, the strain distribution along the fiber's length is determined, and the elastic modulus is derived from this distribution. For the consideration of effects of Poisson's ratio, Kerner's results for particulate composites are adapted as boundary conditions. The effect of differences in Poisson's ratio of fiber and matrix on elastic modulus is studied. Proposed equation shows a good agreement with experimental data of Halpin and Tock, et al.

보강재의 형태와 종류가 금속복합재료의 기계적 물성에 미치는 영향 연구 (Effects of Reinforcements Type on Mechanical Properties of Metal Matrix Composites)

  • 남현욱;조종인;한경섭
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 추계학술발표대회 논문집
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    • pp.79-82
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    • 2001
  • In this research, tile effects of reinforcements type on mechanical properties of MMCs were studied. Six kinds preform were fabricated by using Saffil short fiber, HTZ short fiber, $Al_2O_3$ particle, and SiC particle. MMCs were fabricated by using squeeze casting methods. Various tests were conducted to show the effects of reinforcements type on mechanical properties of MMCs. Tensile and compressive properties of MMCs depend on short fiber, however wear properties depend on particle reinforcement. Generally, properties of fiber/particle hybrid MMCs were excellent than those of MMCs with short fiber.

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자동차 경량화를 위한 단섬유강화 복합재료에서의 섬유생존율이 기계적 물성에 미치는 영향에 관한 연구 (Effects of fiber survival rate on Mechanical properties in Light weight short fiber reinforced composites for Automobile Application)

  • 최영근;이상협;이인섭
    • 한국산업융합학회 논문집
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    • 제4권3호
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    • pp.267-273
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    • 2001
  • In this study, the survival rate of fiber is investigated by nozzle size difference in injection/mold sides. The survival rate of fiber is influenced about the nozzle size differ. Also, The mechanical properties of short carbon glass fiber reinforced polypropylene are experimentally measured as functions of fiber volume fraction and nozzle size difference. These mechanical properties are compared with the survival rate of fiber and fiber volume fraction using image analysis after pyrolytic decomposition. The survival rate of fiber as well as fiber volume fraction is influenced by injection processing condition, the used materials, mold conditions and nozzle sides difference, etc, In particular, the survival rate of fiber is great influenced when injection/mold nozzle sides are different more than that of the same. Consequently, the mechanical properties of short carbon/glass fiber reinforced polypropylene arc improved as the nozzle sides are the same in injection mold sides.

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