• Title/Summary/Keyword: long fiber fraction

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Volume Integral Equation Method for Multiple Isotropic Inclusion Problems in an Infinite Solid Under Uniaxial Tension (인장 하중을 받는 무한 고체에 포함된 다수의 등방성 함유체 문제 해석을 위한 체적 적분방정식법)

  • Lee, Jung-Ki
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.7
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    • pp.881-889
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    • 2010
  • A volume integral equation method (VIEM) is introduced for solving the elastostatic problems related to an unbounded isotropic elastic solid; this solid is subjected to remote uniaxial tension, and it contains multiple interacting isotropic inclusions. The method is applied to two-dimensional problems involving long parallel cylindrical inclusions. A detailed analysis of the stress field at the interface between the matrix and the central inclusion is carried out; square and hexagonal packing of the inclusions are considered. The effects of the number of isotropic inclusions and different fiber volume fractions on the stress field at the interface between the matrix and the central inclusion are also investigated in detail. The accuracy and efficiency of the method are clarified by comparing the results obtained by analytical and finite element methods. The VIEM is shown to be very accurate and effective for investigating the local stresses in composites containing isotropic fibers.

Elastic Analysis in Composite Including Multiple Elliptical Fibers (타원 섬유가 포함된 복합재료에서의 탄성 해석)

  • Lee, Jung-Ki
    • Composites Research
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    • v.24 no.6
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    • pp.37-48
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    • 2011
  • A volume integral equation method (VIEM) is introduced for the solution of elastostatic problems in an unbounded isotropic elastic solids containing interacting multiple isotropic or anisotropic elliptical inclusions subject to remote uniaxial tension. The method is applied to two-dimensional problems involving long parallel elliptical cylindrical inclusions. A detailed analysis of stress field at the interface between the matrix and the central inclusion is carried out for square and hexagonal packing of the inclusions. Effects of the number of isotropic or anisotropic elliptical inclusions and various fiber volume fractions for the circular inclusion circumscribing its respective elliptical inclusion on the stress field at the interface between the matrix and the central inclusion are also investigated in detail. The accuracy and efficiency of the method are examined through comparison with results obtained from analytical and finite element methods. The method is shown to be very accurate and effective for investigating the local stresses in composites containing isotropic or anisotropic elliptical fibers.

Volume Integral Equation Method for Problems Involving Multiple Diamond-Shaped Inclusions in an Infinite Solid under Uniaxial Tension (인장 하중을 받는 무한 고체에 포함된 다수의 다이아몬드 형 함유체 문제 해석을 위한 체적 적분방정식법)

  • Lee, Jung-Ki
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.1
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    • pp.59-71
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    • 2012
  • A volume integral equation method (VIEM) is introduced for the solution of elastostatic problems in unbounded isotropic elastic solids containing multiple interacting isotropic or anisotropic diamond-shaped inclusions subject to remote uniaxial tension. The method is applied to two-dimensional problems involving long parallel diamond-shaped cylindrical inclusions. A detailed analysis of the stress field at the interface between the matrix and the central inclusion is carried out for square and hexagonal packing of the inclusions. The effects of the number of isotropic or anisotropic diamond-shaped inclusions and of the various fiber volume fractions for the circular inclusions circumscribing its respective diamond-shaped inclusion on the stress field at the interface between the matrix and the central inclusion are also investigated in detail. The accuracy and efficiency of the method are examined through comparison with results obtained using the finite element method.

Mineralogical Characterization of Asbestos in Soil at Daero-ri, Seosan, Chungnam, Korea (충남 서산 대로리 일대 토양 내 석면의 광물학적 특성)

  • Kim, Jaepil;Jung, Haemin;Song, Suckwhan;Lim, HoJu;Lee, WooSeok;Roh, Yul
    • Economic and Environmental Geology
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    • v.47 no.5
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    • pp.479-488
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    • 2014
  • Naturally occurring asbestos (NOA) from disturbance of rocks and soils has been overlooked as a source of exposure that could potentially have a detrimental impact on human health. But, few researches on mineralogical characteristics of NOA occurred in soils have been reported in Korea. Therefore, the objective of this study was to investigate the mineralogical characteristics of NOA occurred in soils at Daero-ri area, Seosan, Chungnam Province, Korea. Sedimentation method was used for particle size separation of the asbestos-containing soils. XRD and PLM analyses were used to characterize mineralogical characteristics and mineral assemblages in soils. SEM-EDS and TEM-EDS analyses were used to characterize mineral morphology and chemical composition. Particle size analyses of the asbestos-containing soils showed they were composed of 26-93% sand, 4-23% silt and 3-70% clay. Soil texture of the soils was mainly sand, sandy loam, sandy clay, and clay. PLM analyses of the soil showed that most of the soil contained asbestiform tremolite and actinolite. The average content of asbestos in the soil was 1.5 wt. %. Therefore, the soil can be classified into asbestos-contaminated soils based on U. S. Environmental Protection Agency classification (content of asbestos in contaminated soil > 1%). Morphologically different types of tremolite such as long fibrous, needle-like, fiber bundle, bladed and prismatic forms co-existed. Prismatic tremolite was dominant in sand fraction and asbestiform tremolite was dominant in silt fraction. This study indicates that the prismatic form of tremolite transform gradually into a fibrous form of tremolite due to soil weathering because tremolite asbestos was mainly existed in silt fraction rather than sand fraction.