利用移動車輛反應進行橋梁系統識別

System Identification of A Bridge Based on The Response of A Moving Vehicle

石維屏(Wei-Ping Shih)

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(2010年)

https://doi.org/10.6841/NTUT.2010.00248

摘要

本研究探討使用直接系統參數識別法(Direct system parameter identification，DSPI)針對車輛垂直向歷時反應進行橋梁系統參數識別。首先使用有限元素法來模擬車輛-橋梁互制系統，建立系統的運動方程式，利用時間逐步積分的技巧求解車輛與橋梁之垂直向動態互制反應，將得到的車輛歷時反應代入到ARX數學模型中進行無輸入系統識別，本研究所提出的方法是否能夠準確識別出橋梁的頻率，和車輛的行駛速度、車體的懸吊勁度與懸浮質量有關，因此將進行參數分析以期找出最佳參數使橋梁頻率識別誤差降至最低。此外，考慮橋梁模型中梁的撓曲剛度發生損失來模擬橋梁損傷，根據車輛與橋梁之歷時反應，使用直接系統參數識別法與快速傅利葉轉換，進行橋梁健康診斷。

關鍵字

有限元素 ； 系統識別 ； 車橋互制

並列摘要

This study investigates system parameter identification of a bridge by applying the DSPI (Direct System Parameter Identification) method to the vertical response of a vehicle moving over the bridge. First, we use the finite element method to simulate the vehicle - bridge interaction system and establish the equations of motion of system. Then, the dynamic interaction response between the bridge and the vehicle is solved by a time-step integration scheme. The time series of the vertical response of the vehicle is substituted into the ARX model and system identification is executed without input. This proposed method is able to accurately identify the frequency of the bridge. Because the identified frequencies are related to the moving speed and the suspension stiffness of the vehicle, these parameters are analyzed to find the optimal ones such that the error of the identified frequencies of bridge can be minimized.
In addition, we consider the loss of flexural rigidity of bridge model to simulate the damage of bridge. According to the time series of the response of the vehicle and bridge, we use the DSPI method and FFT (Fast Fourier Transform) to conduct the health diagnosis of a bridge.

並列關鍵字

Finite element method ； system identification ； vehicle - bridge interaction

參考文獻

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