二維三自由度氣彈振動體之減振分析

The Vibration Analysis of a 2 Dimensional 3 DOF Aeroelastic Model

葉詠青(Yung-Ching Yeh)

指導教授 ： 王怡仁

淡江大學/工學院/航空太空工程學系碩士班/碩士(2006年)

https://doi.org/10.6846/TKU.2006.00374

摘要

無論國內或國外，結構振動的發展都已有很長的一段歷史，早期學者們的研究都僅著重在結構本身的設計，然而隨著科技進步，今日橋樑、大樓之結構已愈來愈複雜，並加入了空氣動力學或流體力學等領域來進一步研究，科技產品也都走向微小化及精密化的趨勢，使得結構振動問題變得更複雜，衍生出許多前人未發現之物理現象，等待著人們去了解、去探索。
本研究將先建構一個線性振動結構耦合穩態空氣動力學之系統，加上減振裝置，利用特徵值分析來研究減振裝置的位置對系統的影響。再以三次方非線性彈簧(cubic spring)模擬非線性系統，輔之以非穩態空氣動力學耦合為非線性振動方程式，利用頻率響應以及時域內位移的變化分析減振裝置的位置在非線性系統中所造成的影響。
利用本文所建立之數學模式，對於耦合空氣動力之系統減振，可以利用調整減振裝置位置來達到減振的效果，不必更動原系統參數的設計，相信對工程應用及相關產業具有極佳的應用價值。

關鍵字

非穩態空氣動力學 ； 減振裝置 ； 三次方非線性彈簧

並列摘要

There has been a long history in research and development of structural vibration worldwide. In early stage, scholars were only emphasized on the design of the structure. With the improvement of technologies, bridges and buildings are more complex today. Aerodynamics and fluid mechanics are also incorporated into the design for further studies. Furthermore, the smaller the better is now the trend for new high-tech products which greatly influences the concept of structural vibration that creates more physical phenomenon awaits for people to understand and discover.
This research is first to setup a system with a linear vibration structure doing pitching and plunging in conjunction with a static aerodynamic force and an absorber. The eigen-analysis is utilized to discover the effects of the location of the absorber on the aeroelastic system. In the second part, the cubic spring is employed to simulate a nonlinear vibration system. The unsteady nonlinear aerodynamics is considered and coupled with the nonlinear vibration model. It is found that the location of the absorber plays an important role in the stability of the vibration system.
By using the mathematical model presented in this study, one can adjust the position or design of the absorber to reduce vibration, without changing the main configuration or original design. In conclusion, this model has an enormous applicable value towards application engineering and related fields.

並列關鍵字

Unsteady Aerodynamics ； Absorber ； Cubic Spring

參考文獻

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