放送用アンテナタワーの風振動性状 放送用アンテナタワーの風振動性状を把握することを目的とし,風向方向振動および風直角方向振動について実験的に検討した.風向方向振動については空力実験により風外力を得て,応答解析により風速と応答の関係を導いた.風直角方向振動については空力振動実験から風応答を直接検出した.タワー全体の1次・2次モードについては2自由度振動実験を,ゲイン塔(地上60〜90mのTVアンテナ部)については全弾性模型実験を実施した.ゲイン塔において2次の渦励振(構造物の2次振動と渦発生に伴う周期的外力との共振現象)が観察された.
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Characteristics of Wind Induced Response for Broadcasting Antenna Tower Wind tunnel tests were performed to evaluate the characteristics of wind-induced response for planning broadcasting antenna towers. First, aerodynamic force balance tests were carried out to estimate the along-wind force. The properties of along-wind vibration were calculated by response analyses with the test data. Second, aerodynamic vibration tests were performed to measure the cross-wind vibration of the tower. The resonance of the "gain tower" was observed at specific wind speeds and in specific directions.
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