基于损伤分析的斜拉索监测传感器布设研究

Research on Layout of Stay-cable Monitoring Sensors Based on Damage Analysis

斜拉桥拉索锈蚀乃至断丝将使拉索受力面积变小、应力增加,周边拉索索力重新分布,主梁结构内力状态也随之改变。现阶段斜拉索监测传感器布设大多集中于振动大的长索和拉力大的短索,未考虑拉索锈蚀对桥梁结构产生的影响。本文以某双塔斜拉桥为例,建立有限元模型并进行力学分析,通过模拟拉索锈蚀,分析拉索损伤对周边拉索索力及主梁位移造成的影响,并以此确定损伤较为敏感的拉索。研究表明,在敏感拉索处布置传感器,能反映拉索锈蚀对系统产生的影响,是桥梁健康监测系统的重要组成部分。

The cable force area becomes smaller and the stress increases,the surrounding cables forces are redistributed and the internal forces of the main girder are changed. The above changes are caused by corrosion and broken wires of cables in cable-stayed bridges. At present,the monitoring sensors for stay cables are mostly concentrated on long cables with large vibration and short cables with large tension,while the influence of cable corrosion on the bridge structure has not been considered. In this paper,a Twin Towers cable-stayed bridge is taken as an example,and the finite element model is established and simulated by mechanical analysis. The influence of the cable damage on the surrounding cable force and the displacement of the main girder is analyzed,and the cable which is sensitive to the damage is determined by simulation of the cable corrosion. The studies shows that the sensor arranged at the sensitive cable can reflect the impact of cable corrosion on the system,which is an important part of the bridge health monitoring system.