• Title/Summary/Keyword: 풍직각방향 풍력

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Correlation Analysis of Aerodynamic Forces acting on Tall Buildings with Various Side Ratios (다양한 변장비를 가진 고층건축물에 작용하는 풍력의 상관 분석)

  • Kim, Wonsul;Yoshida, Akihito;Tamura, Yukio
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.2
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    • pp.153-160
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    • 2015
  • The objective of this study is to construct the TPU aerodynamic database with wind tunnel test data of overall wind loads and responses on tall buildings. In this study, wind tunnel tests were conducted to investigate characteristics of wind forces and the effect of wind load combination by cross-correlation analysis among along-wind overturning moment, across-wind overturning moment and torsional moment on a tall building with various side ratios(D/B=0.33, 0.50, 0.77, 0.83, 0.91, 1.0, 1.1, 1.2, 1.3, 2.0 and 3.0) for different terrain roughnesses. The results of wind tunnel tests were compared with those of past literatures. As a result, there was no significant effects of changing of terrain roughnesses on moment coefficients and power spectral densities of across-wind overturning moment coefficients and torsional moment coefficients with various side ratios. Further, these results were good agreement with those of past literatures. From cross-correlation analysis, the across-wind overturning moment coefficients were highly correlated with the torsional moment coefficients. The results of this study will be helpful for practical designers in preliminary design stage.

Wind Tunnel Test Study on the Characteristics of Wind-Induced Responses of Tall Buildings with Openings (중공부(中空部)를 가진 고층건축물(高層建築物)의 풍응답(風應答) 특성(特性)에 관한 풍동실험(風洞實驗) 연구(硏究))

  • Kim, Dong Woo;Kil, Yong Sik;Ha, Young Cheol
    • Journal of Korean Society of Steel Construction
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    • v.17 no.4 s.77
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    • pp.499-509
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    • 2005
  • The excessive wind-induced motion of tall buildings most frequently result from vortex-shedding-induced across-wind oscillations. This form of excitation is most pronounced for relatively flexible, lightweight, and lightly damped high-rise buildings with constant cross-sections. This paper discusses the aerodynamic means ofmitigating the across-wind vortex shedding induced in such situations. Openings are added in both the drag and lift directions in the buildings to provide pressure equalization. Theytend to reduce the effectiveness of across-wind forces by reducing their magnitudes and disrupting their spatial correlation. The effects of buildings with several geometries of openings on aerodynamic excitations and displacement responses have been studied for high-rise buildings with square cross-sections and an aspect ratio of 8:1 in a wind tunnel. High-frequency force balance testshave been carried out at the Kumoh National University of Technology using rigid models with 24 kinds of opening shapes. The measured model's aerodynamic excitations and displacement were compared withthose of a square cylinder with no openings to estimate the effectiveness of openings for wind-induced oscillations. From these results, theopening shape, size, and location of buildings to reduce wind-induced vortex shedding and responses were pointed out.

Proper Orthogonal Decomposition Analysis of Dynamic Wind Pressures Acting on a Tall Tower Model (고층 타워에 작용하는 동적 풍압력의 POD 방법을 이용한 시공간적 특성 해석)

  • Yi, Mee-Hwa;Ham, Hee-Jung
    • Journal of Industrial Technology
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    • v.24 no.B
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    • pp.29-36
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    • 2004
  • The wind and wind-induced dynamic wind pressures fluctuate irregularly according to time and space. In this study, the proper orthogonal decomposition(POD) technique is applied to wind pressures acting on a tall tower model, and the following results are found: the along-wind and across-wind forces can be reconstructed by only four dominant POD modes, and the reconstructed errors are 4.71% and 22%, respectively for across-wind and along-wind directions. The physical meanings for dominant modes are also presented in the paper. The POD analysis can compress complex wind pressure data only by a few dominant modes and interpret spatio-temporal characteristics of wind pressure by novel way while existing statistical methods do not have such benefits.

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