车辆参数对车-桥耦合系统变截面连续梁桥损伤识别的影响

文章研究车-桥耦合系统的非线性振动特性, 采用有限分段思想, 建立 1/4 车辆模型和变截面连续梁桥的车-桥耦合振动方程, 在 MATLAB 环境下编制基于 Runge-Kutta 算法的车-桥耦合振动数值分析程序, 得到桥梁跨中位移响应; 以某三跨混凝土连续梁桥为算例, 分析车桥质量比、车辆速度、车辆弹簧刚度、信噪比 4 组参数的变化对变截面连续梁桥损伤识别的影响。结果发现: 车桥质量比和信噪比较大时, 桥梁损伤识别效果较好; 较低的行车速度有利于桥梁的损伤识别研究; 车辆弹簧刚度的影响非常小, 可忽略不计。

The nonlinear vibration characteristics of vehicle-bridge coupling system are studied. After establishing the vehicle-bridge coupling vibration equation of the common quarter vehicle model and continuous beam bridge with variable cross-section through the finite segmentation idea, the Runge-Kutta method was used to compile the corresponding numerical simulation program of vehicle-bridge coupling vibration under the MATLAB environment. The mid-span displacement response of bridge was obtained. Taking a three-span concrete continuous beam bridge as an example, the influence of four groups of parameters, including vehicle-bridge mass ratio, vehicle speed, vehicle spring stiffness and signal-to-noise ratio (SNR), on the damage identification of continuous beam bridge with variable cross-section was analyzed. The results show that when the vehicle-bridge mass ratio and SNR are large, the performance of bridge damage identification is better; lower driving speed is conducive to the bridge damage identification research; the influence of vehicle spring stiffness is very small, which can be ignored.