• Title/Summary/Keyword: purlin

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An Application of K-$\varepsilon$ Turbulence Model for Predicting Effect of a Rectanguler Obstacle with Heat Flux in a Solt-Ventilated Enclosure on Air Flow

  • 최홍림;김현태;김우중
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.34 no.E
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    • pp.30-44
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    • 1992
  • A modification of the TEACH-like computer program based on the k-$\varepsilon$ turbulence transport was applied for predicting air mixing patterns and temperature distributions in a rectangular, slot-ventilated enclosure having obstructions ; a rectangular obstacle with heat flux, solid walls separates the passage and the pig pens, and purlins beneath the ceiling. Air flow patterns were calculated for the cases with and without the purlin, extending 300mm beneath the ceiling. Comparisons of prediction data of Randall & Battams(1976) showed air flow pattern predicted well for the case without the purlin. Heat was accumulated at the corner of the left side of the solid wall and the right-upper region of the simulated pigs. However the air distribution pattern was completely different from data for the case with the purlin. The deviation from the observation may be attributed to the difference of the geometric configuation. Exploring the cause of the deviation should be conducted in a further study. Temperature stratification was also observed due to incomplete mixing. The obstruction in the route of the inlet air jet at inlet should be avoided since most of kinetic energy dissipates at the abstacle duet to impingement.

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A Study on the Scale and Dimensions of member of Sectional structure for Five-Purlin Houses from Joseon Era (조선시대 민가 오량가(五樑架) 종단구성의 규모와 부재치수에 관한 연구)

  • Kim, Jae-Ung
    • Journal of architectural history
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    • v.28 no.1
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    • pp.7-16
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    • 2019
  • As a part of the research on existing structures of private homes from Joseon Era. Focusing on one hundred twenty five-purlin houses, the current study investigated the features and characteristics of the house structure from style, size, proportion and roof pitch, and measurements of key parts, and developed the following conclusions. Most are single-houses (89, 83%), and among them, there are 47 single front-terrace houses (39%), which is the highest number. The sizes of lower house structure do not differ greatly depending on the vertical structure, and single rear terrace house and double-house have relatively larger side sizes. The size of upper structure is larger in double-houses compared to other vertical structures, indicating a relatively higher roof. The cross-section measurement of major parts show that double-houses are larger than single-houses by 3cm in pillar, 3-4.5cm in crossbeam length, and 4.5cm in crossbeam width. However, Janghyeo width was consistent at 7.5 to 10.5cm, maintaining uniformity regardless of vertical structure of the houses. In addition, the cross-section measurements decreased from sixteenth to nineteenth century, with the size of pillar size decreasing the most. The result that the Janghyeo width is not related to the house structure house confirmed that the Janghyeo width was kept consistent regardless of the size of the house structure.

Development of the Purlin Hanging System Form for the Girder Bridge Slab and Economic Analysis (거더교 상판 콘크리트 타설용 거푸집 개발 및 경제성 분석)

  • Lim, Jeeyoung;Kim, Sunkuk;Son, Kiyoung
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.3
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    • pp.271-278
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    • 2016
  • In the case of South Korea, steel girder bridge (steel box or H-steel) and PSC (Pre-Stressed Concrete) girder bridge are the representative upper structures of railroad and road bridges. These structures account for 75% of the total bridge constructions and 80% of the total construction cost. Since the form work for concreting bridge slab is difficult, various construction methods developed and applied. However, several problems in those methods did not solve partially, including cost increase by material loss and rise of labor costs, quality deterioration by unskilled workers, increased construction time by complicated method, reduced productivity, safety accident by high place work, difficult transportation by big member, and rise of maintenance cost by material characteristic. Alternative method is needed to solve problems of as-is methods. Therefore, the purpose of this study is development of the purlin hanging system form for the girder bridge slab and its economic analysis. Through the findings of this study, it was verified that the purlin hanging system form is possible 60% reduction in cost and 80% reduction in time as comparison with conventional method.

A Study on the Architectural Form and Measuring Unit in Silla Bang, Kyung-Ju (신라방 건축 형식 및 영조척 분석)

  • Ryoo, Seong-Lyong
    • Journal of the Korean housing association
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    • v.27 no.2
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    • pp.43-51
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    • 2016
  • The purpose of this study was to search the architectural forms including the residence plan and wooden structure and the measuring unit in building sites named Bang in Gyeong_Ju, the capiatal of Silla dynasty. It includes the following three historic sites: JaMaeJung-ji, the east district of HwangLyong-sa (S1E1) and InWang-dong historic site. Especially, the data from excavating and studying the east district of HwangLyong-sa were very precious and meaningful. The results were as follows: 1) There are individual characteristics at the sites of JaMaeJung-ji, the east district of HwangLyong-sa and InWang-dong. 2) It is assumed that the builldings of the east district of HwangLyong-sa had most various types of plan and various types of wooden structures. 3) There were various types of wooden structures like as symmetrical or asymmetrical style, regular columnar or irregular columnar style and a third purlin location or a forth purlin location. 4) This study also showed there's a high probability that buildings at Bang sites had been built by the Tang dynaty scale. In Silla dynasty, there was similar tendency to BackJe Dynasty in the way that measuring unit changed according to the times.

Numerical Parametric Analysis of the Ultimate Loading-Capacity of Channel Purlins with Screw-Fastened Sheeting

  • Zhang, Yingying;Xue, Jigang;Song, Xiaoguang;Zhang, Qilin
    • International journal of steel structures
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    • v.18 no.5
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    • pp.1801-1817
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    • 2018
  • This paper presents the numerical parametric analysis on the loading capacity of Channel purlins with screw-fastened sheeting, in which the effects of anti-sag bar and corrugated steel sheet on the ultimate capacity are studied. Results show that the setup of anti-sag bars can reduce the deformations and improve the ultimate capacity of C purlins. The traditional method of setting the anti-sag bars in the middle of the web is favorable. The changing of sheeting type, sheeting thickness and rib spacing has significant effects on the ultimate capacity of C purlins without anti-sag bars, compared with those with anti-sag bars. The proposed design formulas are relatively consistent with the calculations of EN 1993-1-3:2006, which is different from those of GB 50018-2002.

The Experiment for Performance Evaluation of Column-rafter-purlin Connections of an Arch-type Plastic Multi-span Greenhouse (플라스틱 연동온실 기둥-서까래-도리 접합부의 성능 평가 실험)

  • Choi, Man-kwon;Ryu, Hee-ryong;Cho, Myeong-whan;Yu, In-ho;Kim, Seung-yu
    • Journal of Bio-Environment Control
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    • v.29 no.4
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    • pp.473-479
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    • 2020
  • In this study, the structural experiment was conducted with two types of specimens to investigate the mechanical behavior of the column-rafter-purlin connection of an arch-type greenhouse under monotonic loading. Based on the experimental results, the flexural performance was analyzed for two types of connections, and connection classification was attempted. Type B showed 77% of flexural performance compared to Type A, and both types showed that the rigidity and flexural strength did not reach the level of the full rigid. The behavior of the column-rafter-purlin connection was dominated by local buckling due to deformation of the weld and fasteners. As a result of connection classification by AISC standard, both Type A and B connections showed a result that did not meet the rigid connection performance assumed during design, and were classified as simple connection. Therefore, the connection performance evaluation and classification results show that the greenhouse design should be made in consideration of connection performance and in order to design a reliable greenhouse structure, a study on establishing clear design standards for the greenhouse connection is necessary.

Basic Analysis for Optimum Design of Small Scale Vinyl House for Reduction of Damage by Wind and Snow (풍.설해경감을 위한 비규격 비닐하우스의 최적설계를 위한 기초분석)

  • Lee, Jong-Won;Lee, Suk-Gun;Lee, Hyun-Woo;Park, Choon-Wook
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.69-72
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    • 2002
  • The objectives of this study are to analysis structural characteristics of small scale vinyl house and to develope structural analysis program for optimum design. The variation of maximum section forces along the structural characteristics, location and number of purlin was analyzed in vinyl house. It was concluded that the developed structural analysis program could be used usefully for optimum design of small scale vinyl house.

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A Study on the Section of 'Housing Regulations' in The Chronicles of the Three States ("삼국사기(三國史記)" "옥사(屋舍)" 조(條)의 재고찰(再考察))

  • Lee, Sang-Hae
    • Journal of architectural history
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    • v.4 no.2 s.8
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    • pp.45-64
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    • 1995
  • This study examines the Section of 'Housing Regulations' in The Chronicles of the Three States (${\ulcorner}$三國史記${\lrcorner}$ 屋舍條) to verify the residential architecture during the period of the Unified Silla Dynasty. Through the study, the basic architectural terms in the Section of 'Housing Regulations', such as the size of the building, glazing roof tile, animal-shaped ornamental piece on roof ridge, eave purlin, wooden bracket arms, roof decoration, decorative paintings, stone steps, wall structure, blind screen, folding screen, bedstead, and gate are analyzed, interpreted and defined, and, in addition, the forms and styles of the residential architecture during the period of the Unified Silla Dynasty are basically reconstructed.

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Effect of a Supplementary Pole on the Structural Stability in the Single-span Plastic Greenhouses (단동하우스에서의 보강지주 설치 효과)

  • Yum, Sung-Hyun;Kim, Seoung-Hee;Lee, Sang-Bong;Kim, Min-Young;Kim, Chul-Soo
    • Journal of Bio-Environment Control
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    • v.19 no.2
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    • pp.63-69
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    • 2010
  • This study was implemented to clarify the effect of a supplementary pole on the increment of safety snow-depth for the single-span plastic greenhouses which had been run as standardized facilities for 10 to 15 years till April, 2007. In the previous work, some of the basic ideas of the use of a temporary pole were discussed, but application was restricted to both 2-D and the cases which took rafter's specifications into no consideration, and there was also much less experimental information available. So, by modeling the house as the 3-D frame structure, the present study attempted to provide a comprehensive review of the pole's effect through structural analyses as well as measurements. Structural analyses abnormally revealed that the pole regardless of its interval had a negative effect on the structural stability. The results was certainly inconsistent with practical experience and hence implied a necessity of reinforcing the roof purlin. Accordingly, with the purlin being sufficiently reinforced, the plastic greenhouse with the pole's interval of 3~4 m had two times safety snow-depth more than that of the plastic greenhouse without the pole. And the safety snow-depth of five types of the single-span plastic greenhouses according to the pole's intervals was presented.

Test Methods for Evaluation of Slip-Resistance Force of Clamp for Plastic Greenhouse (플라스틱 온실 죔쇠의 미끄럼 저항력 평가를 위한 실험 방법)

  • Choi, Man-Kwon;Song, Ho-Sung;Cho, Myeong-Whan;Yu, In-Ho;Shin, Young-An;Lim, Seong-Yoon;Ryu, Hee-Ryong
    • Journal of Bio-Environment Control
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    • v.25 no.3
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    • pp.193-199
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    • 2016
  • The research discussed experimental results on slip resistance force of rafter-purlin connection of plastic greenhouse and suggested a test method for evaluating slip resistance performance of the connection. Slip resistance forces were measured by four kinds of constraint conditions for specimens, for example, fixing or rolling the end of specimen. According to tests, it is noticed that constraint condition is able to significantly affect the slip resistance force. From a post-hoc comparison result, slip resistance force of test under fixing ends condition was larger than those under the other three constraint conditions. But the slip resistance force results in the fixing ends condition had greater measure of dispersion and three times of standard deviation than those from other constraint conditions. Based on the results obtained, effect of constraint condition for specimen on the slip test should be studied to enhance reliability of evaluation test of the slip resistance performance.