藉由增加系統非線性動力行為之偵測與感應

Detection and sensing based on enhanced nonlinear system dynamics

巫鷹駿(Ying-Chun Wu)

指導教授 ： 尹世洵

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00015

摘要

以往的偵測技術通常建立於量測因結構損害所造成結構振動頻率、振動模態、或相關衍生的結構振動特徵上的改變。然而這些技術對於初期微量的結構損害非常不敏感。因此本研究將藉由在結構系統內加入一非線性回饋迴圈，來提高系統的非線性，使系統產生分歧行為(bifurcation) ，甚至達到渾沌狀態，並利用渾沌系統對於參數變化極敏感之特性，透過狀態空間來觀察系統參數變化所造成之動力行為改變，進而識別結構系統參數之變化。

關鍵字

結構健康監測 ； 損害偵測 ； 非線性 ； 敏感度

並列摘要

The conventional detection techniques are usually based on measuring the changes in natural frequencies, mode shapes, or other derivatives of linear system dynamic characteristics that are caused by structural damage. However, the conventional detection techniques above are not very sensitive to initially small damage. Thus, this research is to enhance system nonlinearity and to make a system generate bifurcation and even chaos by means of adding a nonlinear feedback loop to the system. Due to the sensitivity of a chaotic system to small parametric variations, the changes in system parameters can be identified by observing the changes of the system dynamics in state space.

並列關鍵字

structural health monitoring ； damage detection ； non-linear ； high sensitivity

參考文獻

【1】 Stubbs Norris、Jeong-Tae Kim，1996，Damage Localization in StructuresWithout Baseline Modal Parameters，AIAA，JOURNAL，Vol.34，No.8，pp.1644-1649.

【2】 B. I. Epureanu、S. H. Yin、M. D. Derriso，2005，High-sensitivity damage detection based on enhanced nonlinear dynamics，Smart Materials and Structures，14(2):321–327.

【3】 S. H. Yin、B. I. Epureanu，2005，Enhanced nonlinear dynamics and monitoring bifurcation morphing for the identification of parameter variations，Journal of Fluids and Structures， 21(5-7):543–559.

【4】 B. I. Epureanu、S. H. Yin、E. H. Dowell，2005，Enhanced nonlinear dynamics for accurate identification of stiffness loss in a thermo-shielding panel，Nonlinear Dynamics，39(1-2):197–211.

【5】 S. H. Yin、B. I. Epureanu，2007，Experimental enhanced nonlinear dynamics and identification of attractor morphing modes for damage detection，Journal of Vibration and Acoustics，129:763–770.