공력진동실험을 이용한 고층건물의 변장비 변화에 따른 횡방향 진동응답

유기표(You Ki-Pyo),김한영(Kim Han-Young),조지은(Cho Ji-Eun),김영문(Kim Young-Moon) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.10

Modern flexible tall buildings with reduced damping ratios are sensitive to wind-induced vibrations. Most of the excessive wind-induced vibrations of tall building are due to vortex-induced vibrations. The type of building section model having sectional area of 0.0025㎡ and the height of 0.5m with side ratio denoted as D/B, of 1.0, 2.0, 3.0, 4.0 was selected for aeroelastic experimental study. All measurements were made in a boundary layer wind tunnel at the Chonbuk National University Wind-tunnel Lab. In this paper, the vortex induced vibration of tall buildings with aspect ratio 10 was investigated in turbulent layer flows over suburban areas. Effectiveness of increasing damping ratios was investigated.

동조액체댐퍼를 이용한 고층건물의 공력진동모형실험

유기표(You Ki-Pyo),김영문(Kim Young-Moon) 대한건축학회 2004 大韓建築學會論文集 : 構造系 Vol.20 No.10

Many investigations for reducing wind-induced vibrations of tall building have been conducted. One of them is adding an auxilIary damping device to the building so increase damping ratio of building and reducing responses of the building. In this paper, a passive TLD attached on the top of the aeroelastic building model of which has different side ratio of 2 and 3 and of which aspect raio is 8, was used for wind tunnel test. The boundary layer flow representing suburban area was simulated with normal direction is normal to the small face of the building model. The rms across-wind displacements at the top of the building model which was caused mainly by vortex-induced excitation were measured. It was found out that the effect of vortex-induced excitations of tall building is reduced effect of vortex-induced excitations of tall building 15 TLDs which have mass ratio of 1%-2% and frequency ratio of 0 95-1 05 were used for test. From the test results, maximum TLD effects for reducing vortex-induced excitations appears at the mass ratio of 15% and frequency ratio of 1%.

TMD을 이용한 풍하중을 받는 고층건물의 공력진동응답실험

유기표(You Ki-Pyo) 대한건축학회 2004 大韓建築學會論文集 : 構造系 Vol.20 No.12

The aeroelastic experiment of along and acrosswind vibration was carried out on squire model in a suburban boundary layer. The model tuned mass damper consisted of a small aluminium block cantilevered downward on a piano wire. The TMD mass ratios are respectively 1.0%, 2.0%. The dampers were approximately tuned to the natural frequency of the building model. The type of building section model having sectional area of 0.004㎡ and the height of 0.4m with side ratio denoted as D/B, of 2.0, was selected for aeroelastic experimental study. The lop maximum displacement RMS value appears at TMD2 and generalized mass ratio of 2%.

설시뮬레이션풍동을 이용한 단동형과 연동형 비닐하우스 지붕에 대한 적설하중평가

유기표(You, Ki-Pyo) 대한건축학회 2012 大韓建築學會論文集 : 構造系 Vol.28 No.7

Heavy snowfall has damaged standalone green houses and the typical pattern was, regardless of area, M?shaped collapse resulting from the breakdown of roof rafters by excessive snow load on the roof. As to the pattern of damage to multi?span green houses by heavy snowfall, excessive snow load worked on the hollow parts and pressed the rafters and, as a result, the columns were broken and tilted. This study purposed to analyze snowdrift pattern by conducting a snow simulation wind tunnel experiment on single?span and multiple?span green house roofs using artificial snow. Snow depth was larger on single?span roofs than on multiple?span ones. However, Snow depth on the hollow part between two houses in multiple?span green houses was larger than that on the top of the roof. When three standalone green houses were deployed in parallel, the middle one showed 18?20% larger snow depth than the others. The largest snow depth was measured on the top of each green house, and snow depth at the part where wind direction changed was 20?30% less than that at other parts.

인접건물의 종횡비 변화에 따른 고층건물의 변동풍하중 응답

유기표(You Ki-Pyo),김영문(Kim Young-Moon) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.5

Wind loads on buildings in realistic environments may be considerably either increase or decrease by interference buildings. It is commonly known as interference effect. This effect depend on the geometry and arrangement of these structures, their orientation with respect to the direction of flow and upstream terrain conditions. It is objective of this paper to study the interference effects of the tall buildings which have the different aspect ratios, upstream terrain conditions, distance between adjacent structures and direction of approaching flow. Two types of atmospheric flow conditions which represent open country (α =0.15) and urban flow (α=0.30) environment were simulated in the wind tunnel. The obstructing model used in this study have the aspect ratio of 2, 3 and 4 and the distances between adjacent buildings are 0.5B, 1.0B, 1.5B and 2.0B, which B is the width of the building. Incident wind directions are 0°, 15°, 30° and 45° to the face of the building. And the above experimental results were compared with experimental data measured on isolated building.

방풍망의 종류와 설치거리에 따른 풍속 감속 효과

유기표(Ki Pyo You),최동근(Dong Geun Choi) 한국원예학회 2007 한국원예학회 학술발표요지 Vol.2007 No.6

과수농가의 풍속감소를 위한 방풍팬스의 효과

유기표(You Ki-Pyo),유장열(You Jang-Youl),김영문(Kim Young-Moon) 대한건축학회 2009 大韓建築學會論文集 : 構造系 Vol.25 No.2

Fruit growers install wind fences to prevent fruits from dropping. To examine the effect of wind fences in reducing wind velocity, this study conducted a performance experiment, a farmhouse model wind tunnel experiment, and field measurements, and analyzed how wind fences reduce wind velocity. Among the three types of wind fence with porosities ranging between 30%, 40% and 55%. For the wind fence experiment, we selected two fruit farms growing pears. We modeled the fruit farms and the surrounding topography at a scale of 1/1000. Field measurements to examine the effect of wind fences on wind velocity reduction were made at a real farm, which was Farm 1 in the model experiment. The windbreak performance of the wind fence was highest when its porosity was 40%. According to the result of a field measurements at Farm 1, wind velocity decreased by 92% at 6m behind the shelter fence. This result is almost coincident with the result of an experiment on the performance of a wind tunnel experiment.

압력측정을 위한 튜브시스템에서 튜브탭관의 특성

유기표(You Ki-Pyo),황진택(Hwag Jin-Taik),이후룡(Lee Hoo-Ryong),윤현재(Yoon Hyun-Jae),김영문(Kim Young-Moon) 대한건축학회 2009 大韓建築學會論文集 : 構造系 Vol.25 No.4

Wind pressure experiments are conducted using a pressure transducer in order to examine the change of wind pressure in tall buildings, but the equipment is expensive and difficult to fix directly on the model. Thus, wind pressure experiments are often performed using pipes and tube taps. In many cases, however, because of the reduced scale in wind tunnel experiments and other reasons, the pipe for measuring wind pressure at a specific position of a tall building cannot be maintained constant. Thus, the present study obtained a pressure transfer function according to the length and thickness of tube tap and the shape of tube in the model, and conducted a calibration experiment using a restrictor . The results of the experiment are as follows. 1) The effect of the length of the tube tab installed in the model was insignificant that it was negligible in the tube pressure measuring system using a tube. 2) In case the tube tab was bent when a model was built, the length of the bent part did not have a significant effect on pressure. 3) When the tube installed inside the model was twisted, it did not have a significant effect on the result of wind pressure measurement.

와이블데이터를 이용한 소형풍력발전기 출력에 대한 평가

유기표(You Ki-Pyo),김영문(Kim Young-Moon) 한국태양에너지학회 2012 한국태양에너지학회 논문집 Vol.32 No.2

This study purposed to predict wind energy for small size wind power generators at 50m above the ground in each area using mean wind speed data for 10 minutes collected from 2001 to 2011 by meteorological data in large cities having over 60% of 15 story (50m) or higher apartments including Seoul, Daejeon, Gwangju and Daegu representing the inland region, and Busan, Incheon and Ulsan representing the coastal region. In the results of analysis, we confirmed close agreement between observatory weather data and probability density distribution obtained using Weibull's parameters, and this suggests that Weibull's parameter is applicable to the estimation of wind energy. Hourly output energy using the mean wind speed for 10 minutes and output energy obtained from Weibull's parameter showed an error less than 5%, and thus it was found that wind energy can be evaluated using Weibull's modulus.

모의눈의 상사와 풍동실험장치를 이용한 건축물의 적설형태에 대한 연구

유기표,이후룡,You, Ki-Pyo,Lee, Hoo-Ryong 대한건축학회 2011 대한건축학회논문집 Vol.27 No.4

We need to know snowdrift patterns in order to assess snow load on a building. Various methods have been studied to evaluate snowdrift patterns, but the most effective one is the use of snow particle. This study examined how to simulate of snow particle, and analyzed snowdrift patterns on buildings using a wind tunnel system. Snow particle was produced with sodium bicarbonate. Snowdrift patterns on buildings simulated using snow particle were compared with measured data obtained from a real building (the roof of low-rise building and antarctic building). In the results of wind tunnel experiment with buildings using snow particle, the snowdrift patterns on flat roof and gable roof according to wind velocity agreed well snow accumulation of real building. The form of snow accumulation around the antarctic building was similar to the form of snow accumulation actually measured by Mitusuhashi.