• Title/Summary/Keyword: Roof

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The Thermal Performance Comparison of BIPVT Collector Applied on Roofs and Facades (건물 적용 유형별 BIPVT 집열기 열적 실험성능 비교)

  • Gang, Jun-Gu;Kim, Jin-Hui;Kim, Jun-Tae
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2009.11a
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    • pp.269-272
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    • 2009
  • The temperature of PV modules that integrated into building facades or roof increases that could reduce the electrical efficiency of the PV system. In order to incresae PV system's efficiency it is very important to remove the heat from the PV modules. For this purpose, hot air can be extracted from the space between PV modules and building envelope, and used for heating in buildings. The solar collector utilizing this thermal effect is called photovoltaic-thermal(PVT) solar collector. This paper compares the experimental performance of building-integrated PVT collectors that applied on building roof and facade. There are two different case: a roof-integrated PVT type and a facade-integrated PVT type. The experimental results show that the collected thermal energy of the roof-integrated type was 24% higher, compared to that of the facade-integrated.

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Galloping analysis of roof structures

  • Zhang, Xiangting;Zhang, Ray Ruichong
    • Wind and Structures
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    • v.6 no.2
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    • pp.141-150
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    • 2003
  • This paper presents galloping analysis of multiple-degree-of-freedom (MDOF) structural roofs with multiple orientations. Instead of using drag and lift coefficients and/or their combined coefficient in traditional galloping analysis for slender structures, this study uses wind pressure coefficients for wind force representation on each and every different orientation roof, facilitating the galloping analysis of multiple-orientation roof structures. In the study, influences of nonlinear aerodynamic forces are considered. An energy-based equivalent technique, together with the modal analysis, is used to solve the nonlinear MDOF vibration equations. The critical wind speed for galloping of roof structures is derived, which is then applied to galloping analysis of roofs of a stadium and a high-rise building in China. With the aid of various experimental results obtained in pertinent research, this study also shows that consideration of nonlinear aerodynamic forces in galloping analysis generally increases the critical wind speed, thus enhancing aerodynamic stability of structures.

Study of Analyzing Roof Panel Using Static Implicit Finite Element Method (정적-내연적 유한요소법을 이용한 Roof 판넬 해석에 관한 연구)

  • Ahn Hyun-Gil;Jung Dong-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.3 s.168
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    • pp.78-85
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    • 2005
  • The static implicit finite element method is applied effectively to analyze total roof panel stamping processes, which include the forming stage. complicated and abnormal Large size roof panel was analyzed by using commercial program called AutoForm. Analysis results examining possibility and validity of the AutoForm software and the factor study are presented. Further, the simulated results for the total roof panel stamping processes are shown and discussed. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

A Studyof Materials and Structural Designs in the Glulam Architecture -Focusing in the Roof Structure- (집성재건축의 자재특성과 구조디자인 연구 -지붕구조를 중심으로-)

  • 김란기
    • Korean Institute of Interior Design Journal
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    • no.13
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    • pp.203-215
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    • 1997
  • This Study typed the roof-design in analysis of structural design of the glulam architecture, developed worldwidely, nowaday. For this, it is studied the characters of glulam as the history of glulam architectures, manufacture of glulam, shapes and section of glulam, fireproof and combution of glulam. And it is studied roof-design according to structural type of glulam roof-structure. Conclusively, types of glulam roof design typied as 1)the Simple Beam str., 2)the Multi-Joints continous Beam str. 3)the Hinge str. 4)the Rahmen str. 5)the Archi str. 6)the Grid str. 7)etc str. (Folded-plate str., Radial str., Cylinder Shell str., Ring Dome str., Geodesic Dome str., Conic Coloid Shell str., H.P Shell str. Cantilever Shell str.)

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Unsteady aerodynamic forces on a vibrating long-span curved roof

  • Ding, Wei;Uematsu, Yasushi;Nakamura, Mana;Tanaka, Satoshi
    • Wind and Structures
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    • v.19 no.6
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    • pp.649-663
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    • 2014
  • The present paper discusses the characteristics of unsteady aerodynamic forces on long-span curved roofs. A forced vibration test is carried out in a wind tunnel to investigate the effects of wind speed, vibration amplitude, reduced frequency of vibration and rise/span ratio of the roof on the unsteady aerodynamic forces. Because the range of parameters tested in the wind tunnel experiment is limited, a CFD simulation is also made for evaluating the characteristics of unsteady aerodynamic forces on the vibrating roof over a wider range of parameters. Special attention is paid to the effect of reduced frequency of vibration. Based on the results of the wind tunnel experiment and CFD simulation, the influence of the unsteady aerodynamic forces on the dynamic response of a full-scale long-span curved roof is investigated on the basis of the spectral analysis.

Wind pressures on a large span canopy roof

  • Rizzo, Fabio;Sepe, Vincenzo;Ricciardelli, Francesco;Avossa, Alberto Maria
    • Wind and Structures
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    • v.30 no.3
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    • pp.299-316
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    • 2020
  • Based on wind tunnel tests, this paper investigates the aerodynamic behavior of a large span canopy roof with elliptical plan and hyperbolic paraboloid shape. The statistics of pressure coefficients and the peak factor distributions are calculated for the top and bottom faces of the roof, and the Gaussian or non-Gaussian characteristics of the pressure time-histories in different areas of the roof are discussed. The cross-correlation of pressures at different positions on the roof, and between the top and bottom faces is also investigated. Combination factors are also evaluated to take into account the extreme values of net loads, relevant to the structural design of canopies.

Watertightness Property Evaluation of Rain-Block System (개폐식 대공간 구조물에서 지붕 맞댐부 우수차단 시스템의 수밀성 평가에 관한 연구)

  • Kim, Yun-Ho;Baek, Ki-Youl;Kim, Jong-Su;Lee, Sun-Gyu;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.13-16
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    • 2010
  • This study is an Investigation on the Watertightness Properties of Rain-Block System on the Sliding-Roof Joint of Large-Span Membrane Structures. In this experimental, we test the watertightness performance of joint part of sliding door in roof of large span membrane structure(for pilot project) under environment of rain and wind. A shape of rain water blocking systems of joint part in sliding door verifies the defects and effects of water leakage prevention in precipitation with the wind conditions. For obtaining watertightness of large span membrane structures, it is necessary quality of joints and performance, and quality of membrane material of a retractable roof as well as a closed roof. Also, for obtaining quality in joints, it is essential to make a watertightness guideline for design of large-span membrane.

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The Study of Roof Design for LNG Storage Tank (LNG저장탱크 Roof 설계에 관한 연구)

  • Kim, Y.K.;Lee, K.;Hong, S.H.;Oh, B.T.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.448-452
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    • 2001
  • Natural gas became one of the major sources of energy in Korea. As the consumption of natural gas increase, the more capacity of the LNG storage tanks is required. Recently, Korea Gas Corp.(KOGAS) has developed the technology of designing the LNG storage tanks. In this study, some of the finite element analysis has been made for designing of the roof structure of LNG storage tanks. The load case and safety code used in this study were followed by BS7777.

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Buckling Analysis of Spherical Shells With Periodic Stiffness Distribution According to Shape Parameter (강성분포가 주기성을 갖는 구형쉘의 형상계수에 따른 좌굴해석)

  • Park, Sang-Hoon;Suk, Chang-Mok;Jung, Hwan-Mok;Kwon, Young-Hwan
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.169-175
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    • 2004
  • Researches on spherical shell which is most usually applied have been completed by many investigators already and generalized numerical formula was derived. But the existent researches are limited to those on spherical shell with isotropic or orthotropic roof stiffness, periodic distribution of roof stiffness that can be caused by spherical and latticed roof system is not considered. Therefore, this paper is to develop a structural analysis program to analyze spherical shells that have periodicity of roof stiffness distribution caused by latticed roof of large space structure, grasp buckling characteristics and behavior of structure.

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Wind pressure provisions for gable roofs of intermediate roof slope

  • Stathopoulos, Theodore;Wang, Kai;Wu, Hanqing
    • Wind and Structures
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    • v.4 no.2
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    • pp.119-130
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    • 2001
  • The paper addresses the suitability of wind pressure coefficients specified in contemporary design standards and codes of practice for gable roofs of intermediate slope (roof angle $10^{\circ}-30^{\circ}$). In a recent research study, a series of low building models with different roof slopes in this intermediate range were tested in a boundary layer wind tunnel under simulated open country terrain conditions. This was different from the original study in the 70's, which produced the current provisions on the basis of a model tested only for a single roof slope (4:12) in this range. The results of the study suggest that a modification to the American wind provisions would be warranted to make them more representative of the true local and area-averaged wind loads imposed on gable roofs of intermediate slope.