For a vehicle moving over a bridge, the vehicle-bridge interaction (VBI) embraces the time-varying modal parameters of the system. The identification of non-stationary characteristics of bridge responses due to moving vehicle load is important and remains a challenging task. A new method based on the improved empirical wavelet transform (EWT) along with ridge detection of signals in time-frequency representation (TFR) is proposed to estimate the instantaneous frequencies (IFs) of the bridge. Numerical studies are conducted using a VBI model to investigate the time-varying characteristics of the system. The effects of the measurement noise, road surface roughness and structural damage on the bridge IFs are investigated. Finally, the dynamic responses of an in-situ cable-stayed bridge subjected to a passing vehicle are analyzed to further explore the time varying characteristics of the VBI system. Numerical and experimental studies demonstrate the feasibility and effectiveness of the proposed method on the IF estimation. The identified IFs reveal important time-varying characteristics of the bridge dynamics that is significant to evaluating the actual performance of operational bridges in operation and may be used for structural health assessment.

中文翻译：

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基于经验小波变换的岭提取对车辆行驶桥梁时变参数识别

对于在桥上行驶的车辆，车桥交互（VBI）包含系统的时变模态参数。识别由于移动车辆载荷引起的桥梁响应的非平稳特性很重要，并且仍然是一项具有挑战性的任务。提出了一种基于改进的经验小波变换（EWT）以及时频表示（TFR）中的信号脊检测的新方法来估计桥的瞬时频率（IF）。使用 VBI 模型进行数值研究，以研究系统的时变特性。研究了测量噪声、路面粗糙度和结构损伤对桥梁中频的影响。最后，动态响应原位对过往车辆作用下的斜拉桥进行了分析，以进一步探索VBI系统的时变特性。数值和实验研究证明了所提出的方法在 IF 估计上的可行性和有效性。确定的 IF 揭示了桥梁动力学的重要时变特征，这对于评估运营中桥梁的实际性能具有重要意义，并可用于结构健康评估。