考虑信噪比和车-桥耦合效应的桥梁健康监测策略

为了舍弃大量信噪比低或无异常的数据,节约计算资源并提高分析效率,在理论依据的基础上实现具有针对性的桥梁健康监测,提出了考虑信噪比和车-桥耦合效应的桥梁监测策略.对监测信号成分进行分析,指出为了实现监测策略,需要根据车-桥耦合动力理论确定合理准确的监测阈值.将车群等效为具有主体部分和耦合均布质量的时变动力模型,建立桥梁结构与移动车群相耦合的动力平衡方程及其解析表达式.以一实际简支梁健康监测为例,根据车-桥耦合理论分析车群的均布质量、行驶速度以及振动频率对桥梁动力反应的影响,并结合实际监测数据确定监测阈值,实现监测策略.实验结果表明该监测策略有效.

Health Monitoring Strategy for Bridge Considering Signal-to-Noise Ratio and Vehicle-Bridge Interaction

To abandon a large number of low signal-to-noise ratio data or normal data,the health monitoring strategy for bridge considering signal-to-noise ratio and vehicle-bridge interaction was proposed. Hence,the computing resources were saved effectively and the targeted monitoring based on theory was realized. The composition of the vibration signal was discussed,and the reasonable and accurate monitoring threshold was determined according to vehicles-bridge interaction dynamics. A timevarying dynamic car group model which included a main uniform parameters and coupling mass was established. The dynamic coupling equations for bridge and car group were established and the analytical expression was given. For example,the health monitoring for a simply supported beam was discussed.The dynamic response under different uniform mass,speed and vibration frequency of the car group was analyzed based on vehicles-bridge interaction theory. The monitoring threshold was determined according to simulated result and measured signal,and the monitoring strategy was realized. Results show that the monitoring strategy is feasible.