利用振動訊號診斷橋梁結構損壞之研究

A Study on Diagnosing Damage of Bridge Using Vibration Signals

黎文龍(Wen-Lung Li) ； 璩顥(Hau Chiu)

《中華民國振動與噪音工程學會論文集》 2011 (2011/06) Pp. 21-27

https://doi.org/10.30028/CSSVANNUAL.201106.0021

摘要

本研究主要利用能量損耗的觀念，進行橋梁結構健康度的診斷，並採用新近發展的穩態響應調變之傅立葉係數法(Fourier Coefficient Ratio method, FCR)。FCR法以激振力當作輸入訊號施加於系統之基座，再量測該系統之輸出訊號的穩態響應，將輸入訊號與輸出訊號做乘積調變，找到調變後訊號之傅立葉係數，並且計算出系統阻尼耗能、系統之阻尼、勁度及質量矩陣，最後觀察橋梁結構損壞前後所產生結構特性的變化，達到診斷的效果。並且也會與以往常用在結構診斷中的自然頻率與模態觀察方法去做比較，與一般方式不同的是，本研究之訊號擷取是根據穩態訊號的相位差，所以可以連續執行，以達到能夠隨時進行橋梁結構健康度監測的目的。

關鍵字

橋梁結構 ； 結構能量損耗 ； 結構診斷

並列摘要

The variety of damage detection methods, modal-based techniques have been the most widely investigated due to their global nature and simplicity. Modal-based methods exploit the observable variation in modal parameters before and after the presence of defects in the structure. The present papers is a method for measuring the damping ratio of a structural system that is under base excitations. The method is accomplished by processing the response signal with respect to that of the input. In other words, one is to measure the responses of the system, which is excited by an input sinusoidal signal. Once the response signal is obtained, it can be modulated by two different reference signals. The required dissipative energy, damping ratio, or even system damping can be thus extracted from the modulated signal by the given equation through its Fourier coefficients. In addition, the current method does not require the system damping to be small and valid for a wide range of damping ratios. and valid for a wide range of damping ratios.

並列關鍵字

Bridges ； Structural dissipative energy ； Structural diagnosis