• Title/Summary/Keyword: batten

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Confinement of concrete in two-chord battened composite columns

  • Szmigiera, Elzbieta
    • Steel and Composite Structures
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    • v.19 no.6
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    • pp.1511-1529
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    • 2015
  • This article provides an analysis of the complex character of stress distribution in concrete in stub columns consisting of two HE160A steel sections held together with batten plates and filled with concrete. In such columns, evaluating the effect of concrete confinement and determining the extent of this confinement constitute a substantially complex problem. The issue was considered in close correspondence to rectangular cross section tubular elements filled with concrete, concrete-encased columns, as well as to steel-concrete columns in which reinforcement bars are connected with shackles. In the analysis of concrete confinement in two-chord columns, elements of computational methods developed for different types of composite cross sections were adopted. The achieved analytical results were compared with calculations based on test results.

Vulnerability of roofing components to wind loads

  • Jayasinghe, N.C.;Ginger, J.D.
    • Wind and Structures
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    • v.14 no.4
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    • pp.321-335
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    • 2011
  • The vulnerability of roofing components of contemporary houses built in cyclonic regions of Australia is assessed for increasing wind speeds. The wind loads and the component strengths are treated as random variables with their probability distributions derived from available data, testing, structural analysis and experience. Design details including types of structural components of houses are obtained from surveying houses and analyzing engineering drawings. Wind load statistics on different areas of the roof are obtained by wind tunnel model studies and compared with Australian/New Zealand Standard, AS/NZS 1170.2. Reliability methods are used for calculating the vulnerability of roofing components independently over the roof. Cladding and batten fixings near the windward gable edge are found to experience larger negative pressures than prescribed in AS/NZS 1170.2, and are most vulnerable to failure.

Deflection of battened beams with shear and discrete effects

  • Li, Ji-liang;Chen, Jian-kang
    • Structural Engineering and Mechanics
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    • v.59 no.5
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    • pp.921-932
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    • 2016
  • This paper presents a theoretical analysis for determining the transverse deflection of simply supported battened beams subjected to a uniformly distributed transverse quasi-static load. The analysis considers not only the shear effect but also the discrete effect of battens on the transverse deflection of the battened beam. The analytical solution is obtained using the principle of minimum potential energy. Numerical validation of the present analytical solution is accomplished using finite element methods. The present analytical solution shows that the shear effect on the transverse deflection of battened beams increases with the cross-section area of the main member but decreases with the cross-section area of the batten. The longer the battened beam is, or the larger the moment of inertia of the main member is, the smaller the shear effect will be.

PHOTOMETRIC STUDIES OF THE CONTACT BINARY BV DRACONIS (접촉쌍성 BV Draconis의 측광학적 연구)

  • 이재우;한원용;김천휘
    • Journal of Astronomy and Space Sciences
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    • v.16 no.2
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    • pp.227-240
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    • 1999
  • We performed CCD photometric observations of W UMa type contact binary BV Dra during eight nights from May 1996 to June 1999 using 61cm telescope at Sobaeksan Optical Astronomy Observatory, and completed BV R light curves of the system. From our observations, we derived nine new times of minimum lights (five timings for primary eclipse, four for secondary) and determined new light elements with the times of minima observed since 1999. Our BV R light curves and Batten & Lu(1986)'s radial-velocity ones were simultaneously analyzed with contact mode (Mode 3) of Wilson-Devinney's binary model, and the photometric and spectroscopic solutions for BV Dra were solved. In the analysis, we derived the solutions of 1999 light curves with and without spots, respectively. As the results, asymmetry of light curves may be interpreted as produced by the existence of two spots; hot spot on the secondary and cool on the primary. Combining solutions of light curves and radial-velocity ones, absolute dimensions of BV Dra are $M_1=0.40M_{odot}$, $M_2=1.01M_{odot}$, $R_1=0.72R_{odot}$, $R_2=0.40R_{odot}$. In mass-radius diagram, the less massive and hotter primary component of BV Dra is near TAMS and the secondary is near ZAMS, which is very similar to the other W-type W UMa binaries.

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A numerical method for buckling analysis of built-up columns with stay plates

  • Djafour, M.;Megnounif, A.;Kerdal, D.;Belarbi, A.
    • Structural Engineering and Mechanics
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    • v.26 no.4
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    • pp.441-457
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    • 2007
  • A new numerical model based on the spline finite strip method is presented here for the analysis of buckling of built-up columns with and without end stay plates. The channels are modelled with spline finite strips while the connecting elements are represented by a 3D beam finite element, for which the stiffness matrix is modified in order to ensure complete compatibility with the strips. This numerical model has the advantage to give all possible failure modes of built-up columns for different boundary conditions. The end stay plates are also taken into account in this method. To validate the model a comparative study was carried out. First, a general procedure was chosen and adopted. For each numerical analysis, the lowest buckling loads and modes were calculated. The basic or "pure" buckling modes were identified and their critical loads were compared with solutions obtained using analytical methods and/or other numerical methods. The results showed that the proposed numerical model can be used in practice to study the elastic buckling of built-up columns. This model is considered accurate and efficient for the local buckling of short columns and global buckling for slender columns.

A Study on Explosive Limits of Flammable Materials - Explosive Limits of Ternary System by Means of Solution Thermodynamics and MRSM Model - (가연성물질의 폭발한계에 관한 연구 - 용액열역학 및 MRSM 모델에 의한 3성분계 폭발한계 -)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
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    • v.20 no.3 s.71
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    • pp.91-97
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    • 2005
  • The research on the explosive limits is one of fundamental fields of combustion process, and information on the explosive limits of mixture of fuel and oxidant, with or without additives, is very important for the prevention in industrial fire and explosion accidents. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Batten, Le Chatelier and MRSM(modified response surface methodology) model. In this study, the reference values of lower explosive limits(LEL) of the ethanol+toluene+ethylacetate system were compared with the calculated values by using the solution thermodynamics and the MRSM model, respectively. The values calculated by the proposed equations were a good agreement with literature data within a few percent. By means of this methodology, it is possible to evaluate reliability of experimental data of the lower explosive limits of the flammable mixtures. Also, from given results, it is possible to predict explosive limits of the other flammable liquid mixtures used in the chemical process by the use of the proposed equations.

A Case of Identification of the Cause Using Navigation System and Treatment in the Patient with Nasal Valve Compromise (네비게이션을 이용한 비밸브 기능저하의 원인 규명과 치료 1예)

  • Kim, Ho Chan;Cho, Yong Tae;Kim, Ji Sun
    • Journal of Clinical Otolaryngology Head and Neck Surgery
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    • v.29 no.2
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    • pp.269-275
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    • 2018
  • Nasal valve compromise (NVC) is a distinct cause of symptomatic nasal obstruction, yet there are several ambiguities surrounding the diagnosis and management of this disease. Understanding of nasal valve anatomy with critical assessment of the site of obstruction is essential to effective nasal valve management. Technique selection should be individualized to the type of valve dysfunction. This case report presents a 56 year old man with nasal valve dysfunction due to narrow middle vault, concave lower lateral cartilage and swollen septal body which was diagnosed by various techniques including navigation system and treated by spreader graft, alar batten graft and reduction of septal body.

Parameter Study of Buckling Behavior of Steel Built-up Column (강재 조립 기둥의 좌굴 거동에 대한 매개변수 해석)

  • Kim, Jinyong;Kim, Sung Bo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2A
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    • pp.79-87
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    • 2011
  • The parameter study of buckling behavior of steel built-up column under compression force is presented in this study. The shear deformation effects due to the bending moment and shear forces are considered for the H-shaped main members along the entire built-up column and batten member connecting double H-shaped main members. The parametric study is performed according to the length of the built-up column, the distance of the H-shaped main members and the number and type of cover plate for battens, respectively. The applicability of AISC design specification of normal and high tension bolted built-up column is investigated. The buckling loads for built-up columns are compared with those obtained from the analytic solution developed in this study, AISC specification, and finite element method based on the beam and plate element, respectively.

Seismic behavior of composite walls with encased steel truss

  • Wu, Yun-tian;Kang, Dao-yang;Su, Yi-ting;Yang, Yeong-bin
    • Steel and Composite Structures
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    • v.22 no.2
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    • pp.449-472
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    • 2016
  • This paper studies the seismic behavior of reinforced concrete (RC) walls with encased cold-formed and thin-walled (CFTW) steel truss, which can be used as an alternative to the conventional RC walls or steel reinforced concrete (SRC) composite walls for high-rise buildings in high seismic regions. Seven one-fourth scaled RC wall specimens with encased CFTW steel truss were designed, manufactured and tested to failure under reversed cyclic lateral load and constant axial load. The test parameters were the axial load ratio, configuration and volumetric steel ratio of encased web brace. The behaviors of the test specimens, including damage formation, failure mode, hysteretic curves, stiffness degradation, ductility and energy dissipation, were examined. Test results indicate that the encased web braces can effectively improve the ductility and energy dissipation capacity of RC walls. The steel angles are more suitable to be used as the web brace than the latticed batten plates in enhancing the ductility and energy dissipation. Higher axial load ratio is beneficial to lateral load capacity, but can result in reduced ductility and energy dissipation capacity. A volumetric ratio about 0.25% of encased web brace is believed cost-effective in ensuring satisfactory seismic performance of RC walls. The axial load ratio should not exceed the maximum level, about 0.20 for the nominal value or about 0.50 for the design value. Numerical analyses were performed to predict the backbone curves of the specimens and calculation formula from the Chinese Code for Design of Composite Structures was used to predict the maximum lateral load capacity. The comparison shows good agreement between the test and predicted results.

Das BewuBtsein der conditio humana und der Realitatssinn in der fruhgriechischen Lyrik (초기 그리스 서정시에 나타난 인간의 한계 의식과 현실 감각)

  • 조대호
    • Lingua Humanitatis
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    • v.6
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    • pp.381-405
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    • 2004
  • Elegie und Iambos gehoren zu den altesten Genre der griechischen Lyrik. Erst in diesen Gedichten aus den 7. Jh. v. Chr. beginnt der Dichter als pers nliches Subjekt seine eigenen Erfahrungen auszusprechen, w hrend or im Epos objektiv und leidenschaftslos hinter seinem Stoff zur ckblieb. So behauptet man, dass in den Gedichten der beiden Genre 'das Erwachen der Personlichkeit' (B. Snell) erfolge. Doch dieser pers nliche Charakter der fruhgriechischen Dichtung darf nicht im Sinne der Subjektivit t verstanden werden, wie man sie in der modernen Lyrik findet. Dem subjektiven Gef hl, das in den uns tradierten Fragmenten aus der fr hgriechischen Dichtung zum Ausdruck kommt, kann man n mlich ein gemeinsames Pathos ablesen, das die Elegiker und Iambographen in der Zeit des politischen Umwandels angesichts der conditio humana empfunden batten, das Pathos n mlich, das sich wohl unter dem Begriff amechanie am besten zusammenfassen lasst. In solchen Grenzsituationen, wie Krieg, Ungluck, Altern, sprechen sich die Dichter vollig hilflos aus und beklagen sich uber die menschliche Unwissenheit uber das erh ngte Schicksal. Bezeichnend f r ihre Begegnung mil der Hilflosigkeit des menschlichen Daseins ist jedoch der Realit tssinn, den sie aus ihren Erfahrungen der conditio humara bzw. amechanie gewonnen haben: Sie wollen sich weder durch einen heroischen Gedanken uber den Nachruhm noch durch einen religiosen Glauben an das Jenseits tauschen lassen. Sie wollen vielmehr hic et nunc einen Weg finden, sich mit der amechanie abzufinden. Und dabei werden zwei verschiedene Lebenswege eingeschlagen, der Weg des erotischen Hedonismus (Mimnermos und Semonides) und der des 'sardonischen' Realismus (Archilochos). Damit weisen uns die fruhgriechische Lyrik auf zwei typische Lebensrichtungen hin, die sich spater in der griechischen Ethik einb rgern sollen.

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