• 제목/요약/키워드: structural wood

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재 탄화에 의한 고밀도 우드세라믹 제조 및 성질 - 탄화온도의 영향 - (Properties and Manufacture of High Density Woodceramics by Re-carbonization - Effect of Carbonization Temperature -)

  • 오승원;황정우
    • Journal of the Korean Wood Science and Technology
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    • 제37권6호
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    • pp.517-523
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    • 2009
  • 고밀도 우드세라믹 제조를 위한 기초연구로서 수지함침율 60%인 톱밥보드를 이용하여 탄화온도별로 제조된 1차 탄화 우드세라믹을 수지 재 함침한 후 2차 탄화하여 우드세라믹을 제조하고 그 물성을 조사하였다. 1, 2차 탄화 우드세라믹 성질 비교에서 탄화온도가 높아질수록 2차 탄화 후 중량 및 밀도증가율은 감소하였고 탄화온도 $600^{\circ}C$일 때 1차 탄화 시보다 중량은 21.7%, 그리고 밀도는 1차 탄화 시 $0.68g/cm^3$에서 2차 탄화 시 $0.82g/cm^3$로 20.6% 증가하여 최고치를 나타냈다.

수지함침율이 고밀도 우드세라믹 제조와 물성에 미치는 영향 (Effect of Percentage of Resin Impregnation on the Preparation of High Density Woodceramics and the Physical Properties)

  • 오승원;전순식
    • Journal of the Korean Wood Science and Technology
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    • 제36권3호
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    • pp.39-46
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    • 2008
  • 고밀도 우드세라믹을 제조하기 위한 기초연구로서 수지함침율에 따라 제조된 1차 탄화 우드세라믹을 수지 재함침 후 2차 탄화하여 우드세라믹을 제조하고 그 물리적 성질을 조사하였다. 1, 2차 탄화 우드세라믹의 성질 비교에서 수지함침율이 증가함에 따라 2차 탄화 후 중량 및 밀도증가율은 감소하였고, 수지함침율 40%일 때 1차 탄화 시보다 중량은 23.8%, 그리고 밀도는 30.0% 증가하여 최고치를 나타냈다.

Evaluation of Dowel Bearing Strength of Structural Composite Lumber(SCL) on the Effect of Moisture Content

  • Oh, Sei Chang
    • Journal of the Korean Wood Science and Technology
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    • 제31권3호
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    • pp.61-69
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    • 2003
  • This study investigated the effect of moisture content and loading direction on dowel bearing strength of two types of SCL. Dowel bearing tests of LVL and PSL were conducted with two different MC level, 7.5% and 19%, and two different oriention, L-direction(loading parallel to grain) and X-direction(loading perpendicular to grain). Most of specimens showed typical load-deformation curves and intersected 5% offset line. Failure modes were classified into two categories; spliting(for L-direction specimens) and peeling(for X-direction specimens). Dowel bearing strength generally decreased with increasing MC. The decreasing rate was more significant in X-directon. ESG also decreased with increasing MC, and the ratio of ESG of 7.5% versus 19% was about 1.47. Dowel bearing strength of LVL and PSL in L-direction was higher than that of X-direction. This results indicated that MC and loading orientation had a significant effect on dowel bearing strength of SCL. The average dowel bearing strength of LVL were higher than that of PSL in each loading direction. Two types of probability distribution model were chosen to quantify strength distribution, normal and 2-parameter weibull distribution. The two models showed good agreement with the data, especially in lower tail of the cumulative distribution. Normal and 2-parameter weibull distribution seemed to proper model of the dowel bearing strength for each MC levels.

Revisiting the Vāstupuruṣamaṇḍala in Hindu Temples, and Its Meanings

  • Kim, Young Jae
    • Architectural research
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    • 제16권2호
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    • pp.45-56
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    • 2014
  • The objective of this article, positively recognizing existing researches, is to revisit some aspects regarding the Vāstupuruṣamaṇḍala with a square grid work which is a fundamental planning guideline to control the construction of a Hindu temple and a mathematical doctrine to lead ritual programs. Hence, this paper suggests some reservations as to certain details such as temple constructions. In order to lay hold on its meaning, this paper touches upon the specific matters about the Vāstupuruṣamaṇḍala in the building construction of Hindu temples, which set out to shed light on four concerns; first, it explores the formation process of the Vāstupuruṣamaṇḍala in concert with the evolution of Hindu temples over time; second, it considers differences and similarities in comparison with other texts intimately articulated with the construction of temples, and then understands the relationship between their local languages and applications to the Vāstupuruṣamaṇḍala; third, it examines the symbolic and sanctified process of the temple's construction on the Vāstupuruṣamaṇḍala grids with two- or three-dimensional computer graphics (by means of the Auto Cad and Rhino tools), invisibly situating the divinities within it and illuminating the roles of ornamentation in the structural terms of temples; fourth, it presents that there are another rules on the building construction based upon architect-priest's craftsmanship skilled as a stonemason or a carpenter in the manual processes of the temples' construction for proper measurements and truncations of stone and wood closely linked together structural stability of completed temples. In conclusion, proceeding from what has been said above, this thesis shows that the Vāstupuruṣamaṇḍala grid includes both practical and spiritual meanings to construct a Hindu temple.

한중일 전통가구에 나타난 표현과 의미의 기호학적 분석 - 17~19세기 수납가구를 중심으로 - (Semiotic Analysis of Expressive Features and Structural Meanings in Traditional Furniture of Korea, China and Japan - Focus on the Storage Furniture from 17th to 19th century -)

  • 김은정;박영순
    • 한국실내디자인학회논문집
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    • 제22권1호
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    • pp.183-193
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    • 2013
  • The study aimed to find the fundamental differences of aesthetics in Korea, China, and Japan by analyzing expressive features and structural meanings of the storage furniture from $17^{th}$ to $19^{th}$ century. The study was performed in four steps; analysis of expressive features, isotopic analysis, semantic structure analysis, and comprehensive interpretation. The results showed that three countries had linear shapes with curvilinear elements, closed forms with open spaces, natural material hues with change of tone or color, and symmetrical forms with asymmetrical patterns and structures in common. Korea comparatively accented on the natural material colors and wood grains. China stressed on the big and wide faces using three-dimensional carving. Japan accented on the linear elements with strong color contrast and decorative metal fixtures. These features were caused by the traditional thoughts and according aesthetic principles. Korea and China were affected by the Confucianism focused on establishing the order of rank. Meanwhile, Japan was more influenced by the Buddhism emphasized on the individuality and communication. Therefore, the differences of the expressive features in furniture among the three countries were inevitable consequences of the different ideologies.

Correlation of wind load combinations including torsion on medium-rise buildings

  • Keast, D.C.;Barbagallo, A.;Wood, G.S.
    • Wind and Structures
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    • 제15권5호
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    • pp.423-439
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    • 2012
  • Three common medium- rise building forms were physically tested to study their overall wind induced structural response. Emphasis was placed on the torsional response and its correlation with other peak responses. A higher correlation was found between the peak responses than between the general fluctuating parts of the signals. This suggests a common mechanism causing the peak event, and that this mechanism is potentially different to the mechanism causing the general load fluctuations. The measurements show that about 80% of the peak overall torsion occur simultaneously with the peak overall along wind drag for some generic building shapes. However, the peak torsional response occurs simultaneously with only 30%-40% of the peak overall drag for the rectangular model. These results emphasise the importance of load combinations for building design, which are often neglected in the design of medium sized rigid buildings for which the along-wind drag is dominant. Current design wind loading standards from around the world were evaluated against the results to establish their adequacy for building design incorporating wind-induced torsion effects. Although torsion is frequently neglected, for some structural systems it may become more important.

종굽힘강도시험방법을 이용한 폴리에틸렌 보트 선체의 구조 설계 (Structural Design of Polyethylene Boat Hull by using Longitudinal Bending Strength Test Method)

  • 조석수
    • 한국산학기술학회논문지
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    • 제16권12호
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    • pp.8447-8454
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    • 2015
  • 레저 보트 선체의 구조설계규격과 재료는 ISO 12215-5에 규정되어 있으며 선체 전장이 2.5m이상 24m미만이면서 선체재료가 강, 알루미늄, FRP등에 대해서만 적용할 수 있다. 따라서 선체 전장이 2.5m이하이거나 선체 재료가 ISO 12215-5의 규정 재료이외인 레저 보트인 경우 ISO 12215-5의 구조설계규격을 적용시킬 수 없고 ISO 12215-5의 부속서에 규정된 낙하시험만으로 구조 신뢰성을 확보할 수 있다. 그러나 선체낙하시험은 제작된 선체에 대하여 적용하는 것은 가능하나 선체를 구조설계단계에서 적용하는 것은 상당한 설계 및 시험 비용등을 초래하므로 현장 적용성이 떨어진다. 따라서 본 연구에서는 이러한 문제점을 극복하기 위하여 일본 소형 선박 검사 사무 규정 세칙에서 제안하고 있는 선체의 종굽힘강도시험규격을 폴리에틸렌 보트 선체의 구조 설계에 응용하여 ISO 12215-5의 비선급표준재료로 제작된 폴리에틸렌 보트의 종굽힘강도시험규격의 허용 설계 변위 기준을 제안하였다.

벽식 구조체 적용을 위한 구조용단열패널 성능 평가 (Evaluation on Structural Performance of Structural Insulated Panels in Wall Application)

  • 나환선;이현주;이철희;황성욱;조혜진;최성모
    • 복합신소재구조학회 논문집
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    • 제3권2호
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    • pp.19-27
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    • 2012
  • Structural insulated panels, which are structurally performed panels consisting of a plastic insulation bonded between two structural panel facings are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. By now, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to suggest fundamental reports such as racking resistance, axial capacity, transverse load capacity, and lintel load capacity for SIPs. Test results showed that maximum load was 44.3kN, allowable load was 14.7kN for racking resistance, and that maximum load was 137.6kN, allowable load was 37.4kN/m for axial compression capacity. For transverse load capacity, test results showed $10.3kN/m^2$ of maximum load, $3.4kN/m^2$ of allowable load. For lintel load capacity for SIPs dependent to lengths, allowable loads were 20.4kN for 600mm long lintel, 23.9kN for 1,200mm long lintel, 19.3kN for 1,800mm long lintel, and 2,400mm long lintel had 14.1kN of allowable load. In the near future, when the allowable load for wall application is established, SIPs is considered to substitute the existent post-and-lintel construction to bearing wall structure.

Abortiporus biennis에 의한 유기용매 리그닌의 생물학적 변환과 환원제 첨가에 따른 구조 변화 (Biomodification of Ethanol Organolsolv Lignin by Abortiporus biennis and Its Structural Change by Addition of Reducing Agent)

  • 홍창영;박세영;김선홍;이수연;유선화;최인규
    • Journal of the Korean Wood Science and Technology
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    • 제44권1호
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    • pp.124-134
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    • 2016
  • 본 연구에서는 백색부후균 Abortiporus biennis를 이용하여 유기용매 리그닌의 생물학적 변환을 시도함으로써, 생물학적 변환 기작을 이해하고, 상업적 활용을 위해 유기용매 리그닌의 저분자화를 유도하고자 하였다. 질소제한 배지에서 A. biennis는 주로 유기용매 리그닌의 중합반응을 유도하면서, 분자량을 급격히 증가시켰으며, 배양일에 따라 구조적 차이를 야기하였다. 배양 초기, ether 결합의 분해를 통해 phenolic OH 함량이 증가한 반면, 배양 후기에는 ether 결합이 증가함에 따라 phenolic OH 함량이 감소하였다. 이러한 결과를 바탕으로, 유기용매 리그닌의 탈중합을 유도하기 위해 환원제인 ascorbic acid를 첨가하여 유기용매 리그닌의 구조 변화 및 변환 산물을 분석하였다. 결과적으로, 환원제의 첨가에 의해 유기용매 리그닌의 분자량은 소폭 증가하였지만, 환원제 무첨가 실험에 비해 그 증가 폭이 현저히 감소하였다. 또한 배양액 내 리그닌 올리고머의 경우, 배양 10일째 환원제를 첨가한 실험구에서 중량 평균 분자량 381 Da, phenolic OH 함량 38.63%을 나타냈으며, 이는 저분자화된 형태로 상업적 활용 가치가 높다고 사료된다. 결론적으로, A. biennis의 효소 시스템은 유기용매 리그닌의 분해보다 중합을 야기하였으며, 환원제의 첨가를 통해 배양액 내 리그닌 올리고머의 저분자화 및 phenolic OH 함량 증가를 유도할 수 있었다.

국산 구조용 집성재의 환경부하 정량화를 위한 온실가스 배출량 분석 (Assessment of Carbon Emission for Quantification of Environmental Load on Structural Glued Laminated Timber in Korea)

  • 장윤성;김세종;손휘림;이상준;심국보;여환명;김광모
    • Journal of the Korean Wood Science and Technology
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    • 제44권3호
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    • pp.449-456
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    • 2016
  • 본 연구의 목적은 국산 구조용 집성재를 대상으로, 제조과정의 탄소배출을 정량화하고 탄소배출 저감방안을 제시하는 것이다. 총 2개소의 구조용 집성재 제조업체를 대상으로 원료, 수송, 제조 공정, 제조에 의한 에너지소비량 등을 현장 실사하였다. 현장에서 수집한 자료 및 구축된 전과정목록과 같은 관련문헌을 토대로 단위부피당 탄소배출을 정량화하였다. 국산 구조용 집성재의 제재 및 건조, 집성 공정별 온실가스 배출결과는 각각 31.0, 109.0, 94.2 kg $CO_2eq./m^3$으로 나타났다. 수입 구조용 집성재와 비교하였을 때 약 13% 온실가스를 적게 배출하는 것으로 나타났다. 또한 기존의 건조 에너지원을 바이오매스로 전환시에는 기존 대비 37%의 온실가스를 감축하여 친환경성을 제고할 수 있을 것으로 판단되었다. 본 결과는 향후 목조주택의 환경성을 규명하기 위한 전과정평가 수행 시, 투입된 목재제품의 전과정목록분석을 위한 기초자료로 활용될 것으로 기대된다.