並列タイトル等Spectrum Analysis of the Response of Multi-Degree-of-Freedom Linear Systems under Nonstationary Input and its Application to Airplane Response in Atmospheric Turbulence
タイトル（掲載誌）航空宇宙技術研究所報告 = Technical Report of National Aerospace Laboratory TR-559
一般注記線型多自由度系への非定常入力を決定的包絡線関数と定常過程との積で表わし,系の応答のスペクトル解析を行った。結果を任意階数の変調スペクトルで表示した。これらはPriestleyによる定義,並びに定常解析を特別な場合として含むものである。応用例として航空機の突風応答解析をとり上げ,一般座標についての変位,速度,加速度応答と,それらを重ね合せた全応答を求める式を導いた。数値計算結果より得られた主な結論は,加速度応答が立上りで定常値より高い極大値をとるので従来の定常解析だけでは不十分であることである。
An exploratory study was conducted to establish the spectrum representation of the response of the multi-degree-of-freedom linear system, under the nonstationary input which is characterized by a product of a deterministic function and a stationary random process. New spectrum expressions are derived to describe the cross spectrums of the output within an arbitrary order. The present result includes the definition by Priestley, as a special case, and has been reduced to the stationary spectrum when a deterministic function is set constant. In order to demonstrate feasibility of the nonstationary spectrum analysis the second order statistics, of the response of the model airplane under nonstationary atmospheric turbulence, are obtained in terms of the evolutionary cross spectrums of the generalized coordinates(displacement), their first derivatives(velocity) and their second derivatives(acceleration). It is shown that the total responses of these quantities, superposition of the various modes, can be computed at any positions of interest on the airplane wing. Some numerical examples are given to evaluate the relative contributions of rigid and flexible modes to the total responses. One main conclusion from this study is the fact that the present method is very useful in estimating the maximum mean square at the transient stage of the acceleration response, which has been overlooked by the conventional stationary analysis.
資料番号: NALTR0559000
レポート番号: NAL TR-559
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース（IRDB）（機関リポジトリ）
提供元機関・データベース宇宙航空研究開発機構 : 宇宙航空研究開発機構リポジトリ