Recent studies have highlighted the superiority of the drive-by method using vehicle responses to identify bridge frequencies due to its cost-effectiveness. However, most research identifies bridge and vehicle frequencies as time-invariant, which neglects the non-stationary nature of vehicle–bridge interaction systems. This assumption holds true only when the vehicle’s mass is significantly less than that of the bridge. With an increase in vehicle–bridge mass ratio, relying on this assumption can lead to substantial errors, necessitating an investigation of time-varying characteristics extracted from vehicle responses. This study extends this exploration to extract time-varying frequencies of a vehicle–bridge interaction system involving a two-axle vehicle and a bridge through the drive-by method and improved multisynchrosqueezing transform. The semi-analytical solution for time-varying frequencies is newly derived, and numerical simulations are employed to verify the solution and the effectiveness of the improved multisynchrosqueezing transform. Various influencing factors, including vehicle speed, vehicle damping, bridge damping, stiffness of the bridge and vehicle, environmental noises, and road roughness, are analyzed. Additionally, laboratory experiments with a scaled two-axle vehicle and two bridge models are conducted to verify the proposed method, and case studies on different parameters are further provided. Results demonstrated that the time-varying bridge frequency can be extracted from vehicle responses using the proposed approach. Finally, a novel index is proposed to evaluate the extraction results of the bridge’s time-varying frequency from vehicle responses.

中文翻译：

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使用路过方法和改进的多同步挤压变换研究交互过程中两轴车辆和桥梁的时变频率


最近的研究强调了使用车辆响应来识别桥梁频率的驾驶方法的优越性，因为它具有成本效益。然而，大多数研究将桥梁和车辆频率视为时不变的，忽略了车桥交互系统的非平稳性质。仅当车辆的质量明显小于桥梁的质量时，该假设才成立。随着车桥质量比的增加，依赖这种假设可能会导致很大的误差，因此有必要研究从车辆响应中提取的时变特征。本研究扩展了这一探索，通过路过法和改进的多同步挤压变换来提取涉及两轴车辆和桥梁的车桥相互作用系统的时变频率。新推导了时变频率的半解析解，并通过数值模拟验证了该解以及改进的多同步挤压变换的有效性。分析了各种影响因素，包括车速、车辆阻尼、桥梁阻尼、桥梁和车辆的刚度、环境噪声和道路不平整度。此外，还进行了比例两轴车辆和两个桥梁模型的实验室实验来验证所提出的方法，并进一步提供了不同参数的案例研究。结果表明，可以使用所提出的方法从车辆响应中提取时变桥梁频率。最后，提出了一种新的指标来评估从车辆响应中提取桥梁时变频率的结果。