• 제목/요약/키워드: wooden beam

검색결과 58건 처리시간 0.028초

목제(木製) 프러쉬 문의 함수율 변동에 따른 틀어짐과 좌굴 예측모델 (I) : 예측모델과 실측치 비교 (Warping and Buckling Prediction Model of Wooden Hollow Core Flush Door due to Moisture Content Change (I) : Comparison of Prediction Model with Experimental Results)

  • 강욱;정희석
    • Journal of the Korean Wood Science and Technology
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    • 제27권3호
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    • pp.99-116
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    • 1999
  • 목재 hollow core 형태의 프러쉬문은 가구과 목공품 산업에서 주요 제품으로 사용중 틀어짐과 좌굴은 매우 중요한 문제이다. 틀어짐은 도아 표면재 간의 물리적 및 기계적 성질의 차이에 기인된다고 알려져 있다. 본 연구는 수치적 모델덜을 사용해 틀어짐과 좌굴을 예측하는데 그 목적이 있다. 여러 환경조건에서 경질섬유판과 합판으로 만들어진 프러쉬문에 대한 각 모델들과 실측치간의 비교를 하였다. 문의 틀어짐과 좌굴을 예측하기 위해 3가지 연속체 모델, 즉 보, 판상 및 판상-좌굴 모델이 채택되었다. 틀어짐은 고습에서보다 저습에서 현저하게 훨씬 현저하게 발생되었으며, 포아송 비를 고려한 판상 모델은 저습에서 보 모델보다 더 정확하게 틀어짐을 예측할 수 있었다. 그러나 고습에서 좌굴이 문의 표면재에 발생하기 때문에 판상-좌굴 모델 이 모든 시험범위에서 가장 적절하였다.

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SMART 보 거푸집 개발을 위한 요구조건 분석 (Requirement Analysis for Development of SMART Beam Form)

  • 김태구;임채연;김선국
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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    • pp.70-71
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    • 2014
  • The structural work is the main process of building construction which influence on the time, cost, safety and quality. The form work is one of the main process which has from 20 to 30 percentage of structural work. Especially the form work for beams is complex and need more manpower compared with form work for column or slab. When the existing forms such as plywood form, steel framed wooden form and aluminum form, is used for form work of beam, it would result in the cost overrun caused by needs of lots of manpower and resources. Therefore, the aim of this study is analysis of the requirement for development of SMART beam form. The result of this study shall be used for the development of SMART form work system.

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접촉요소를 적용한 전통목조 도리방향 프레임의 변위이력 시뮬레이션에 관한 연구 (Simulation of displacement history using contact element in traditional wooden frame)

  • 황종국;홍성걸;정성진;이영욱;김남희;배병선
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2006년도 정기 학술대회 논문집
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    • pp.421-426
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    • 2006
  • To examine the behaviors of traditional wooden structural frame in Korea in direction of beam, an experimental study was performed. The interior frame of Daewoongjeon of Bongjeongsa was selected as a model, which has two short exterior columns and one high inside column. The experimental frame has 1/2 scale and lateral forces are applied at high inside column by using drift control. The vertical gravity loads are applied on the frame. From the results of experiment it was shown that the stiffness and lateral capacity of the frame was increased when vertical loads are applied and the force-drift relationship in positive load direction was not same as in negative load direction. And push-over analysis are performed by using macro model in which the rotational and shear springs which were derived from the another experiments of subassemblies were used. The numerical analysis with macro model showed a good correspondence with the experiment within 2% story drift.

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고려(高麗) 금동탑(金銅塔)을 통해 본 법주사(法主寺) 팔상전(捌相殿)의 구조형식계통(構造形式系統) (The Structural Lineage of Palsangjeon in Pubjoo Temple Analyzed through Gilt-bronze Pagoda in the Koryo Period)

  • 김경표
    • 건축역사연구
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    • 제14권1호
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    • pp.89-105
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    • 2005
  • The central aim of this thesis is to see if the structure of Palsangjeon(捌相殿) in Pubjoo Temple(法住寺), a five sto wooden pagoda in Chosen(朝鮮) Dynasty, was handed down from the ancient and middle ages. This study was performed through an analysis of Gilt-Bronze Pagoda built in Koryo(高麗) period. In other words, it is aimed at analyzing which lineage the structure of Palsangjeonbelongs to as a wooden pagoda. In analyzing the structure of Palsangjeon, I attempted to find out its source from the remains of Koryo period prior to the Chosen Dynasty. Examples are the Gilt-Bronze Pagoda, built during the Koryo period. I have also examined its relationship with other existing wooden pagodas and remains. The analysis of Palsangjeon, a five story wooden pagoda in Chosen Dynasty, focuses on the following: First, I explored the possibilities of whether the structure of Palsangjeon was newly invented in Chosen Dynasty, or if it had been derived from the wooden pagodas in the Koryo period. Secondly, I tried to find out if the stable vertical planes, with a great successive diminution ratio, were derived from the middle age, i.e. Koryo period. The results of the study of Palsangjeon through Gilt-Bronze Pagoda analysis are as follows: 1. The structure of Gilt-Bronze Pagoda, a wooden pagoda from the Koryo period, is roughly classified into the accumulation type, using pipe pillars, and the one story type using whole pillars. In the accumulation type, stories are connected in either a flat format or an intervening format. The Gilt-Bronze Pagoda is mainly composed of pipe pillars, with some whole pillars. However, the central pillar was omitted in the building structure. Generally, the upper and lower stories are connected by pipe pillars in a crutch format. All the pillars, whether they are pipe pillars or whole pillars, used Naiten(內轉) technology. The Eave supporter has the Haang type(下昻) and the Muhaang type(無下昻). In most cases, high balustrades are furnished, but few tables of high balustrades have been found. The slanting roof formats have been handed down from Paekche(百濟), Silla(新羅), or Koryo(高麗). However, the structure of the octagon is assumed to be derived from Koguryo(高句麗). The structure of the Gilt-Bronze Pagoda from the Koryo period is mainly composed of accumulated flat squares, with some spire types. intervening format, the structure of Palsangjeon used whole pillars in a half story format in which upper level side pillars are installed on the lower level tie beam. From the Bronze Pagoda from the Koryo period, we can assume that the half story format of wooden pagodas that has stable vertical planes with a great successive diminution ratio was created during the mid-Koryo period at the latest and had been idly developed by the time of the Chosen Dynasty. 3. The whole pillars in Palsangjeon are also found in Gilt-Bronze Pagodas from the Koryo period. Hence, all of the pillars in Palsangjeon seem to have been handed down from the ancient construction technology. They were also used in the construction of wooden pagodas from the Koryo period. Therefore, it is assumed that Palsangjeon was constructed using the construction technology of the Chosen Dynasty that had been developed from the wooden pagoda construction technology of the Koryo period. The stable vertical planes with a great successive diminution ratio in Palsangjeon are derived from ancient Korean wooden pagodas, which have developed into indigenous Korean wooden pagodas with fairly stable vertical planes and a great design, in the half story format of Koryo and Chosen Dynasty. Therefore, it is assumed that the structure of Palsangjeon has a systematic relationship with traditional Korean wooden pagodas and is one of the indigenous Korean wooden pagoda structures. 4. In China, the intervening format has been mainly used between stories in multi-story architecture since the ancient days. At the same time, the flat format as also used in ancient and middle ages. However, the flat format was replaced by whole pillars during the Ming(明) and Manchu(淸) Dynasties, in favor of simple and compact construction. The half-story format, in which upper level side pillars are installed on tie beams, has been found in some cases, but it doesn't seem to have been the primary construction technology. Few traces of the half-story format have been found in multi-story architecture in Japan, and it has not been used as a general construction format. By contrast, the half-story format, which seems to have been derived from the Koryo period, was used as a general construction format in multi-story architecture of the Chosen Dynasty. The construction technology of multi-story architecture is related to that of multi-story wooden pagodas, but they have different production technologies. It seems that the structure of Palsangjeon did not just adopt the construction technology of multi-story architecture in the Chosen Dynasty, but it was developed from wooden pagodas in the Koryo period, including the Gilt-Bronze Pagoda. 5. Since the ancient days, most Chinese and Japanese wooden pagodas have adopted an accumulation type of structure using pipe pillars, with accumulated pointed towers. On the other hand, though most Korean wooden pagodas have also adopted an accumulation type of structure from the ancientdays, one story type using whole pillars was created in the Koryo and Chosen Dynasties. The wooden pagoda structure of Palsangjeon, with stable vertical planes in a half story format, is a unique Korean construction technology, different from the construction technologies of Chinese and Japanese wooden pagodas. This thesis clearly determined the structural characteristics of Palsangjeon. However, various remains have yet to be analyzed in depth, to establish an accurate construction technology system. In the beginning of this thesis, I had difficulty in precisely interpreting the internal structure of the Gilt-Bronze Pagoda from its appearance. However, in the process of study, the more serious problem was that there are few remains or ruins of multi-story architecture in ancient and the middle ages of Korea. Therefore, it is urgent to discover various remains in the future. This thesis succeeded in determining the structural characteristics of Palsangjeon. However, it fell short of clarifying the structural lineage of the stable vertical planes, although they show indigenous Korean architectural taste, representing the unique national emotion, and the construction format of multi-story wooden pagodas in Korea. I hope this is clarified in the future research.

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Comparison of accuracy between panoramic radiography, cone-beam computed tomography, and ultrasonography in detection of foreign bodies in the maxillofacial region: an in vitro study

  • Abdinian, Mehrdad;Aminian, Maedeh;Seyyedkhamesi, Samad
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제44권1호
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    • pp.18-24
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    • 2018
  • Objectives: Foreign bodies (FBs) account for 3.8% of all pathologies of the head and neck region, and approximately one third of them are missed on initial examination. Thus, FBs represent diagnostic challenges to maxillofacial surgeons, rendering it necessary to employ an appropriate imaging modality in suspected cases. Materials and Methods: In this cross-sectional study, five different materials, including wood, metal, glass, tooth and stone, were prepared in three sizes (0.5, 1, and 2 mm) and placed in three locations (soft tissue, air-filled space and bone surface) within a sheep's head (one day after death) and scanned by panoramic radiography, cone-beam computed tomography (CBCT), and ultrasonography (US) devices. The images were reviewed, and accuracy of the detection modalities was recorded. The data were analyzed statistically using the Kruskal-Wallis, Mann-Whitney U-test, Friedman, Wilcoxon signed-rank and kappa tests (P<0.05). Results: CBCT was more accurate in detection of FBs than panoramic radiography and US (P<0.001). Metal was the most visible FB in all of modalities. US was the most accurate technique for detecting wooden materials, and CBCT was the best modality for detecting all other materials, regardless of size or location (P<0.05). The detection accuracy of US was greater in soft tissue, while both CBCT and panoramic radiography had minimal accuracy in detection of FBs in soft tissue. Conclusion: CBCT was the most accurate detection modality for all the sizes, locations and compositions of FBs, except for the wooden materials. Therefore, we recommend CBCT as the gold standard of imaging for detecting FBs in the maxillofacial region.

송(宋) 《영조법식(營造法式)》 중 월량(月梁) 보머리 가공 규범에 대한 고찰 (A Study on Manufacturing Norms of Wollyang(月梁) Head in the 《Yeongjobeosig(營造法式)》 Song Dynasty)

  • 이용준
    • 한국농촌건축학회논문집
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    • 제21권3호
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    • pp.33-40
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    • 2019
  • Woolyang(月梁) is a beam which whole shape is curved like a so-called moon(月). According to the ${\ll}$Yeongjobeosig(營造法式)${\gg}$, In the case of beams installed under the ceiling of a wooden building, it is used by manufacturing them in Woolyang(月梁) for maximum visual decorative effects as the shape is exposed. In order to achieve the end of a beam that is manufacturing in Woolyang(月梁), it is important to process it in a suitable size and shape for a given situation to achieve a combination with other members around it. However, in the "營造法式", the standard of production of the Woolyang(月梁) is divided into Myeongbog(明?), Chagyeon(箚牽), Pyeonglyang(平梁), and the height of each beam head is divided into 21分$^{\circ}$, 15分$^{\circ}$, 25分$^{\circ}$, but it is not possible to look at any more specific reference. In this paper, try to consider the principle of Woolyang(月梁) manufacturing and its normative contents which were indirectly proposed in the ${\ll}$Yeongjobeosig(營造法式)${\gg}$.

GFRP적층판을 활용한 보강보부재와 원통형 단판적층기둥재 접합부의 내력 성능평가 (Structural Performance of Joints for Partial Reinforced Beam Using GFRP Laminated Plate and Cylindrical Reinforced LVL Column)

  • 송요진;정홍주;이정재;서진석;박상범;홍순일
    • Journal of the Korean Wood Science and Technology
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    • 제42권3호
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    • pp.282-289
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    • 2014
  • 합판과 유리섬유강화플라스틱을 조합하여 적층 후 $1.96N/mm^2$의 압력으로 $150^{\circ}C$에서 1시간 고밀화시킨 유리섬유 강화플라스틱 적층판을 제작하였다. 제작된 5가지의 유리섬유강화플라스틱 적층판을 각각 기둥재와 접하는 집성재에 부착하여 부분보강보부재를 제작하였다. 더불어 합판과 시트형 유리섬유강화플라스틱을 적층한 보강적층목재핀과 유리섬유로 보강한 원통형 단판적층기둥재로 기둥-보 접합부를 제작하였다. 기준시험편으로는 원주목과 집성재로 제작한 보부재, 드리프트핀을 사용한 접합부를 제작하여 모멘트 저항 내력을 평가하였다. 시험결과 기준시험편과 비교하여 부분보강보부재를 사용한 시험체들이 평균 1.8배 높은 내력성능이 측정되었다. 모든 부분보강보부재와 원통형 단판적층기둥재에는 파단이 발생하지 않았으며 접합부의 인성과 강성이 모두 양호하게 측정되었다. 부분보강보부재의 보강효과는 시트형 유리섬유강화플라스틱이 직물형 유리섬유강화플라스틱으로 보강한 적층판보다 양호한 보강효과를 보였으며, 시트형 유리섬유강화플라스틱을 각층에 삽입한 적층판이 접합내력과 변형각 모두 양호하여 보부재의 부분보강에 적합한 것을 확인하였다.

Evaluation of The Moment Resistance Joint Strength of Larch Glulam Using Glass Fiber Reinforced Wood Plate

  • Song, Yo-Jin;Jung, Hong-Ju;Park, Hyun-Ho;Lee, Hak-Young;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • 제42권5호
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    • pp.571-578
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    • 2014
  • As a way of developing wooden joint development, a glass fiber reinforced wood plate was manufactured to replace a steel plate. Also, the fracture toughness was evaluated. Through application to a cantilever-type specimen made of a column and a beam, the moment resistance performance was evaluated. For the fracture toughness specimen of the wood plate, 12 types were manufactured by varying the combination of a main member (veneer and plywood) and reinforcement (glass fiber sheet and glass fiber cloth). The results of the fracture toughness test indicated that the 5% yield load of the specimen using plywood was 18% higher than that of the specimen using veneer, and that the specimen reinforced by inserting glass fiber sheets between testing materials (Type-3-PS) had the highest average 5% yield load 4841 N. Thus, a moment resistance strength test was performed by applying Type-3-PS to a column-beam joint. The results of the test indicated that compared to the specimen using a steel plate and a drift pin (Type-A), the maximum moment ratio of the specimen using a glass fiber reinforced wood plate (Type-3-PS) and a drift pin (Type-B) was 0.79; and that a rupture occurred in the wood plate due to high stiffness of the drift pin. The maximum moment ratio of the specimen using a glass fiber reinforced wood plate (Type-3-PS) and a glass fiber reinforced wooden laminated pin (Type-C) was 0.67, which showed low performance. However, unlike Type-A, a ductile fracture occurred on Type-C, and the load gradually decreased even after the maximum moment.

통일신라건축 목조결구기법에 관한 연구 (The Study on the Jointing Method of Wooden Members at Unified Silla Architecture)

  • 황세옥;허범팔
    • 건축역사연구
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    • 제18권1호
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    • pp.7-29
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    • 2009
  • In understranding the essence of the Korea traditional Architecture, it is important to consider the jointing methods of architectural members, architectural technologies, etc. Especially the purpose of this study is understanding on the Jointing Method of Wooden Members in the period of Unified Silla Architecture. It's conclusion is summarized as follows. 1. A section of column has very close to do with the foundation stone. The structures of foundation stone and column are generally concluded by butt joint, arrow-head joint, housed joint by Grang-e method. Judu is structured by arrow-head joint And, in general, beam is structured by Sagaematchum Chumcha and sagaljudu of Don direction. At the head of Pyungju and the body of Goju, Changbang is structed by Jangbumachum with arrow-head joint or by jumukchang-machum. Also, it is surmised that Gyisoseum and Anssolim methods had been applied to columns from former ages. The example can be found at Bagjae Mireuksaji stone pagoda. Bagjae Mireuksaji stone pagoda taking wooden-pagoda form adopts Gyisoseum and Anssolim methods. We can also find such a sort of methods from other stone constructions like Budo, etc. 2. Injahwaban is structured by short Changbumachum with arrowed-head joint at upper members, and by Anjangmachum at the lower part. This sort of Gongpo style can be seen in the mural painting of tomb of Koguryo and in Buplyungsa, Buplyunsa, Bupkisa-located in Japan, which are influenced by Bakjae or Unified Silla. It is considered that at the end of the late United Silla, Injawhaban had been replaced with Chumcha and Soro on the Pyungbang under influence of Dapo style from China.

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Flexural Behavior of Laminated Wood Beams Strengthened with Novel Hybrid Composite Systems: An Experimental Study

  • Mehmet Faruk OZDEMIR;Muslum Murat MARAS;Hasan Basri YURTSEVEN
    • Journal of the Korean Wood Science and Technology
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    • 제51권6호
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    • pp.526-541
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    • 2023
  • Wooden structures are widely used, particularly in earthquake zones, owing to their light weight, ease of application, and resistance to the external environment. In this study, we aimed to improve the mechanical properties of laminated timber beams using novel hybrid systems [carbon-fiber-reinforced polymer (CFRP) and wire rope]. Within the scope of this study, it is expected that using wood, which is an environmentally friendly and sustainable building element, will be more economical and safe than the reinforced concrete and steel elements currently used to pass through wide openings. The structural behavior of the hybrid-reinforced laminated timber beams was determined under the loading system. The experimental findings showed that the highest increase in the values of laminated beams reinforced with steel ropes was obtained with the 2N reinforcement, with a maximum load of 38 kN and a displacement of 137 mm. Thus, a load increase of 168% and displacement increase of 275% compared with the reference sample were obtained. Compared with the reference sample, a load increase of 92% and a displacement increase of 14% were obtained. Carbon fabrics placed between the layers with fiber-reinforced polymer (FRP) prevented crack development and provided significant interlayer connections. Consequently, the fabrics placed between the laminated wooden beams with the innovative reinforcement system will not disrupt the aesthetics or reduce the effect of earthquake forces, and significant reductions can be achieved in these sections.