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%.

측벽 개방유무에 따른 축사지붕면의 풍압계수 특성분석

유기표,You, Ki-Pyo 한국공간구조학회 2011 한국공간구조학회지 Vol.11 No.2

축사는 비닐하우스 다음으로 자연재해에 취약한 농촌시설물이다. 축사의 경우 측벽 없이 지붕만 있는 형태가 가장 많이 사용되고 있는데, 태풍이 불면 지붕 전제가 날아가 많은 피해가 발생하는 실정이다. 그래서 농가에서는 태풍피해예방을 위한 측벽에 윈치 커튼설치하여 피해를 예방하고 있는 실정이다. 본 논문에서는 측벽 개방에 따른 축사지붕에 위치별 풍압 계수 분포특성에 대해서 알아보고자 한다. 측벽유무에 관계없이 축사지붕면의 피크외압계수분포에서 풍향각 $0^{\circ}$로 불어오는 방향에 대해서 불리하게 작용하고 있는 것을 알 수 있다. 그러나 측벽의 유무에 따라 피크외압계수가 풍향각과 처마의 길이에 영향을 받는 것을 확인할 수 있었다. Livestock buildings are rural facilities as vulnerable to natural disasters as vinyl houses. Many of livestock buildings have a roof but without side walls. The roof of such structures is easily blown away by a typhoon and this results in a heavy loss. Therefore, farmers install winch curtains on the sides to prevent damages caused by typhoons. This study purposed to examine the distribution of wind pressure coefficient among different positions of livestock shed roof according to the opening of side walls. It was found that according to the distribution of peak external pressure coefficient on the roof surface of livestock shed, the wind blowing at wind angle $0^{\circ}$ was disadvantageous to roof surface regardless of the presence of side walls. However, it was confirmed that the peak external pressure coefficient was affected by wind angle and the length of eave depending on the presence of side walls.

방풍망의 종류와 설치거리에 따른 풍속 감속 효과

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

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.

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%.

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.

기상대 적설 측정 바람막이팬스의 성능평가

유기표,김영문,유장열,백선영,You, Ki-Pyo,Kim, Young-Moon,You, Jang-Youl,Paek, Sun-Young 한국공간구조학회 2014 한국공간구조학회지 Vol.14 No.2

Meteorological observatories use measuring boards on even ground in open areas to measure the amount of snowfall. However, it is very difficult to evaluate the accurate amount of snowfall because of the effects of the wind. Therefore, this study tried to determine the internal wind flow inside a windbreak fence to identify an area that was not affected by wind in order to measure the snowfall. We performed a computational fluid dynamics analysis, wind tunnel test of the type and height of the windbreak fence, and analyzed the wind flow inside the fence. The results showed that a double windbreak fence was better than a single windbreak fence for reducing the wind velocity. The reduction of the wind velocity was highest in the middle of a windbreak fence with a width of 4 m and a height of 60cm, where the windbreak fences were fixed to the ground.

동조액주관댐퍼의 고유진동수와 오러피스에 대한 감쇠 특성

유기표(You Ki-Pyo) 대한건축학회 2010 大韓建築學會論文集 : 構造系 Vol.26 No.4

Orifices are installed on the horizontal tube of a tuned liquid column damper in order to increase the coefficient of head loss of the damper. Because such orifices control the flow of the horizontal tube, there is a variation in the level of water in the vertical tube. In general, only one orifice is installed in the middle for controlling the flow of the horizontal tube. In this study, examined the damping characteristic of a tuned liquid column damper according to porosity, the number of orifices installed and natural frequency. Amplitude response was lower when orifices were not installed than when they were, and the lower amplitude response increased the head loss coefficient. Compared to when only one installed, when two orifices were installed amplitude response decreased by up to 7%.

태양열 집열판에 작용하는 풍압계수 분포 특성

유기표,김영문,유장열,You, Ki-Pyo,Kim, Young-Moon,You, Jang-Youl 한국공간구조학회 2013 한국공간구조학회지 Vol.13 No.2

This paper attempted to bridge this gap by identifying the number of flat-plate solar collectors. The characteristics of wind pressure coefficients acting on flat-plate solar collectors which are most widely used were investigated for various wind direction. Findings from this study found that the location where the maximum wind pressure coefficient occurred in the solar collector was the edge of the collector. Regarding the characteristics according to the number of collectors, the paper found that downward wind pressure coefficient of the lower edge of the collector was higher than the upward wind pressure coefficient of the upper edge of the collector in the basic module (1 piece). However, as the number of collectors increases, the upward wind pressure coefficient of the upper edge become higher than the downward wind pressure coefficient of the lower edge. Finally yet important, it was found that the location of the maximum wind pressure coefficient was changed according to the number of solar collectors.

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.