• Title, Summary, Keyword: analytical properties

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Modeling and prediction of buckling behavior of compression members with variability in material and/or section properties

  • Gadalla, M.A.;Abdalla, J.A.
    • Structural Engineering and Mechanics
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    • v.22 no.5
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    • pp.631-645
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    • 2006
  • Buckling capacity of compression members may change due to inadvertent changes in the member section dimensions or material properties. This may be the result of repair, modification of section properties or degradation of the material properties. In some occasions, enhancement of buckling capacity of compression members may be achieved through splicing of plates or utilization of composite materials. It is very important for a designer to predict the buckling resistance of the compression member and the important parameters that affect its buckling strength once changes in section and/or material properties took place. This paper presents an analytical approach for determining the buckling capacity of a compression member whose geometric and/or material properties has been altered resulting in a multi-step non-uniform section. This analytical solution accommodates the changes and modifications to the material and/or section properties of the compression member due to the factors mentioned. The analytical solution provides adequate information and a methodology that is useful during the design stage as well as the repair stage of compression members. Three case studies are presented to show that the proposed analytical solution is an efficient method for predicting the buckling strength of compression members that their section and/or material properties have been altered due to splicing, coping, notching, ducting and corrosion.

Selecting optimized mix proportion of bagasse ash blended high performance concrete using analytical hierarchy process (AHP)

  • Praveenkumar, S.;Sankarasubramanian, G.;Sindhu, S.
    • Computers and Concrete
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    • v.23 no.6
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    • pp.459-470
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    • 2019
  • Apart from strength properties, durability, toughness and workability are also important criteria in defining the performance of a concrete structure. Hence "High Performance Concrete (HPC)" is introduced. It is different from high strength concrete and can have various applications. In this paper, the properties (Mechanical and Durability) of High Performance Concrete blended with bagasse ash at 5%, 10%, 15% and 20% are studied. However, it is difficult to analyze the performance based on different properties obtained from different experiments. Hence it is necessary to combine all the criteria/properties into a single value to obtain a result by a technique called Analytical Hierarchy Process (AHP).It is an effective tool for dealing with complex decision making, and may aid the decision maker to set priorities and make the best decision. In addition, the AHP incorporates a useful technique for checking the consistency of the decision maker?s evaluations, thus reducing the bias in the decision making process.

Analytical Properties for Insoluble Fraction of Yeast Extract by Autolysis (자기소화법에 의한 효모 Extract중 불용성 물질의 분석화학적 특성)

  • 김재웅;김동희
    • The Korean Journal of Food And Nutrition
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    • v.8 no.4
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    • pp.280-288
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    • 1995
  • Because yeast is rich in vitamins, nucleotides and essential amino acids, it has been used as a nutrient and dietary supplements. Particularly yeast extract functions as a seasoning, flavor enhancer in meats. In this study, naturally occurring insoluble components during yeast extract process by autolysis were microanalyses by using SEM, XRD, HPLC, GC, FT-lR and DSC. On the basis of useful datas, authors have characterized the analytical points for the purpose of improving products in the preparation of yeast extract.

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Comparisons of Magnetic and Magneto-Optic Properties between Fe-rich and Nd-rich Amorphous $Nd_xFe_{1-x} $Alloys

  • Kim, Jae-Young;Kim, Jeoung-Hoon;Oh, Hyun-Woo
    • Journal of Magnetics
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    • v.3 no.2
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    • pp.49-54
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    • 1998
  • Dependence of magnetic and magneto-optic properties on composition of amorphous NdFe alloys has been studied to identify a promising magneto-optic recording material in the wavelength of a blue laser beam. From the view point of crystallographic state, perpendicular magnetic anisotropy energy and polar Kerr rotation angle, the Nd-rich region was found to be suitable for the research purpose.

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A study on the prediction of the mechanical properties of nanoparticulate composites using homogenization method with effect interface concept (유효계면 모델과 균질화 기법을 이용한 나노입자 복합재의 역학적 물성 예측에 관한 연구)

  • Jang, Seong-Min;Yang, Seung-Hwa;Yu, Su-Young;Cho, Maeng-Hyo
    • Proceedings of the KSME Conference
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    • pp.684-689
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    • 2008
  • In this study, homogenization method combined with the effective interface model for the characterization of properties of the nanoparticulate composites is developed. In order to characterize particle size effect of nanocomposites, effective interface model has been developed. The application range of analytical micromechanics approach is limited because a simple analytical approach is valid only for simple and uniform geometry of fiber particles. Therefore this study focuses on the analysis of mechanical properties of the effect interface through the continuum homogenization method instead of using analytical micromechanics approach. Using the homogenization method, elastic stiffness properties of the effective interface are numerically evaluated and compared with the analytically obtained micromechanics solutions. The suggested homogenization method is expected to be applied to optimization problems for nanocomposite design.

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Analytical Determination of Out-of-Plane Thermo-elastic Properties for Laminated Composite Plate (복합재 라미네이트의 두께방향 열탄성 물성치 계산)

  • Kim, Kyung-Pyo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2407-2414
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    • 2015
  • This paper presents analytical expressions for the determination of out of plane thermo-elastic properties for conventional laminated composite plates. The approach follows that commonly accepted for in-plane properties. Results over a variety of lay-ups reveals that it is poor assumption to use transverse tape lamina properties to represent out of plane laminate properties for laminates with more than 10% plies oriented off-axis($90^{\circ}$) from uniaxial or for laminates with angle plies of $15^{\circ}$ or greater.

Electronic and Optical Properties of amorphous and crystalline Tantalum Oxide Thin Films on Si (100)

  • Kim, K.R.;Tahir, D.;Seul, Son-Lee;Choi, E.H.;Oh, S.K.;Kang, H.J.;Yang, D.S.;Heo, S.;Park, J.C.;Chung, J.G.;Lee, J.C.
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.382-382
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    • 2010
  • $TaO_2$ thin films as gate dielectrics have been proposed to overcome the problems of tunneling current and degradation mobility in achieving a thin equivalent oxide thickness. An extremely thin $SiO_2$ layer is used in order to separate the carrier in MOSFETchannel from the dielectric field fluctuation caused by phonons in the dielectric which decreases the carrier mobility. The electronic and optical properties influenced the device performance to a great extent. The atomic structure of amorphous and crystalline Tantalum oxide ($TaO_2$) gate dielectrics thin film on Si (100) were grown by utilizing atomic layer deposition method was examined using Ta-K edge x-ray absorption spectroscopy. By using X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy (REELS) the electronic and optical properties was obtained. In this study, the band gap (3.400.1 eV) and the optical properties of $TaO_2$ thin films were obtained from the experimental inelastic scattering cross section of reflection electron energy loss spectroscopy (REELS) spectra. EXAFS spectra show that the ordered bonding of Ta-Ta for c-$TaO_2$ which is not for c-$TaO_2$ thin film. The optical properties' e.g., index refractive (n), extinction coefficient (k) and dielectric function ($\varepsilon$) were obtained from REELS spectra by using QUEELS-$\varepsilon$(k, $\omega$)-REELS software shows good agreement with other results. The energy-dependent behaviors of reflection, absorption or transparency in $TaO_2$ thin films also have been determined from the optical properties.

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