This paper examines the effect of traversing vehicles on the vibration of the supporting bridge. It shows that the effect of vehicle–bridge interaction (VBI) on the mechanical system of the bridge breaks down into three constituent mechanisms: (a) an additional damping, (b) an additional stiffness, and (c) a modified loading term. The study characterizes these three mechanisms with explicit analytical expressions in the case of a single-degree of freedom (SDOF) vehicle–SDOF bridge system. The analysis reveals that the impedance ratio—defined as the ratio of the vehicle’s damping to the bridge’s mechanical impedance—is a dominant coupling parameter of VBI, in addition to the (well-known) vehicle-to-bridge stiffness ratio. Subsequently, the study proposes an original approach, namely the Modified Bridge System (MBS) method, to decouple the VBI problem when the stiffness ratio is small. The MBS approach solves a modified bridge system, independent of the traversing vehicle. Numerical applications on simply supported railway bridges show that the MBS method outperforms other decoupling approaches, such as the moving load approximation. At the same time, compared to the solution of the coupled vehicle–bridge system, the proposed MBS method is equally accurate but computationally more efficient. The paper also outlines limitations of the proposed approach related to the single-mode representation of both vehicle and bridge.

中文翻译：

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一种表征和解耦车桥相互作用的改进桥梁系统方法

本文研究了横穿车辆对支座桥梁振动的影响。它表明车桥相互作用（VBI）对桥梁机械系统的影响分解为三个组成机制：（a）附加阻尼，（b）附加刚度，和（c）修改后的加载项。在单自由度 (SDOF) 车辆-SDOF 桥梁系统的情况下，该研究通过明确的解析表达式来表征这三种机制。分析表明，除了（众所周知的）车桥刚度比之外，阻抗比（定义为车辆阻尼与桥梁机械阻抗之比）是 VBI 的主要耦合参数。随后，该研究提出了一种独创的方法，即改良桥梁系统 (MBS) 方法，在刚度比较小时解耦 VBI 问题。MBS 方法解决了修改后的桥梁系统，独立于行车。在简支铁路桥梁上的数值应用表明，MBS 方法优于其他解耦方法，例如移动荷载近似。同时，与车桥耦合系统的解决方案相比，所提出的 MBS 方法同样准确，但计算效率更高。该论文还概述了与车辆和桥梁的单模表示相关的拟议方法的局限性。例如移动载荷近似。同时，与车桥耦合系统的解决方案相比，所提出的 MBS 方法同样准确，但计算效率更高。该论文还概述了与车辆和桥梁的单模表示相关的拟议方法的局限性。例如移动载荷近似。同时，与车桥耦合系统的解决方案相比，所提出的 MBS 方法同样准确，但计算效率更高。该论文还概述了与车辆和桥梁的单模表示相关的拟议方法的局限性。