| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥500,000 (Direct Cost: ¥500,000)
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| Research Abstract |
For tall buildings with more than 300m, the aero-elastic instability like vortex induced vibration, galloping and flutter could be occurred to lead their structural failure. In this research, effects of building shape, structural damping, approaching flow characteristics and natural frequency ratio of bending and torsional vibration on the aero-elastic instability were investigated mainly by wind tunnel tests. From the investigation, the following results are obtained.
1) The vortex induced vibration occur in strong turbulent flow like flow over urban terrain for a building with a shallow section.
2) The aero-elastic instability is limited within the angle attack of 0 - 15ﾟ for any building shapes and types of flow.
3) The bending vibration is not so much affected by the torsional vibration. On the other hand, the torsional vibration is greatly influenced by the bending vibration. When the natural frequency of the torsional vibration is close to that of the bending vibration, the torsional flutter suppressed by the energy transfer to the bending vibration.
4) The cutting, rounding of a building corner is very effective to reduce the aeroelastic instability. Particularly, a very small step back at the corner has a great effect to suppress the vortex induced vibration.
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