关键词: 桥梁工程, 响应信号, 随机子空间算法, 真实模态, 模态参数识别

Abstract: In practical engineering, in order to detect whether the bridge structure was in good operation state at any time, various types of sensors were usually installed on the bridge structure. The modal parameters were obtained by analyzing the response signals collected by the sensors, and the change law of modal parameters was analyzed to indirectly evaluate the operation state. Based on this, in order to improve the accuracy of modal parameter identification, aiming at the deficiency of the most commonly used modal parameter identification algorithm, stochastic subspace algorithm (SSI), a real modal selection algorithm was proposed, which took the frequency value, damping ratio and modal shape as the discriminant factors. Finally, the proposed algorithm was applied to identify the modal parameters for a large cable-stayed bridge. The recognition results show that the proposed algorithm can not only effectively realize the intelligent filtering of real modes, but also the recognition results are reliable.

Key words: bridge engineering, response signal, stochastic subspace identification, real modal, modal parameter identification