基于车桥耦合等截面连续梁桥单损伤识别研究

Research on single damage identification of continuous beam bridge with equal section based on vehicle-bridge coupled vibration

文章基于车桥耦合振动分析的基本理论,选用1/4车辆模型,对等截面连续梁桥进行单处裂缝损伤的识别研究。首先计算得到连续梁桥的振型函数,然后利用编写的程序模拟车辆匀速驶过桥梁的过程,求解车桥耦合振动的方程得出车辆及桥梁关键特殊位置的响应。基于该文改进的非线性车桥耦合振动方程求解无损伤和有损伤时桥梁竖向振动响应直接进行损伤识别,无需再进行特殊的信号处理。以某三跨等截面连续梁桥作为研究对象,进行单处裂缝损伤的工况分析。研究结果表明,可以通过桥梁跨中竖向位移出现偏差的位置区间和偏差的大小程度,辅以跨中竖向位移响应的变化规律,判别出裂缝损伤的位置范围以及相对损伤程度。

Based on the basic theory of vehicle-bridge coupled vibration,the damage identification of a single crack in a continuous beam bridge with equal section was studied using a quarter vehicle model.Firstly,the vibration mode function of the continuous beam bridge was obtained.Then,the program was written to simulate the process of the vehicle passing through the bridge at a constant speed,and the response of the vehicle and the bridge at key special positions was obtained by solving the equation of vehicle-bridge coupled vibration.Based on the vertical vibration response of the non-damaged and damaged bridge obtained by solving the improved nonlinear vehicle-bridge coupled vibration equation,the damage was identified directly without special signal processing.Taking a three-span continuous beam bridge with equal section as the research object,the damage of single crack at a single location was analyzed.The result showed that the location range and relative damage degree of the crack could be identified by the location interval and the magnitude of the deviation of the vertical displacement in the middle of the span,supplemented by the variation law of the vertical displacement response in the middle of the span.