The Cable-stayed Bridge Health Monitoring System Optimal Sensor Placement

As a effective method to obtain the structural signal and to identificate the damage of the bridge, health monitoring can provide scientific basis for assessing the security status of the bridge and for the management of the bridge. In recent years, it has been widely paid attention to. Sensor placement in health monitoring system is directly related to the efficiency and precision of the overall system. The aim of sensor optimal placement is to use less sensor to obtain more bridge structural information and to asure the information to be more conducive to bridge damage identification.Cable-stayed bridge is a very common type in the modern long span bridges, the research on the optimization of the sensor placement for their health monitoring system is of great significance. In response to the structural and behavior characteristics of cable-stayed bridge, this issue was researched combined with the existing placement principles in this paper.Three dimensional cable-stayed bridge model was established in large-scale finite element analysis software Ansys, and the modal analysis, the strain analysis and the thermodynamic analysis to this model was carried on. According to the analysis result,the trait of bridge structural behavior was researched, and the result was treated as the important basis for the sensor placement; According to the environment and the common damage type of cable-stayed bridge, the type of sensors was chosen, and the major technique parameters were determined. Through the research on the method of damage identification for cable-stayed bridge and the damaged structure's behavior, the number of the accelerate sensor in the health monitoring system was determined. Under the direction of the optimization theory for sensor placement, sensors were placed by using genetic algorithm method combined with tradition experience and bridge's actual analysis result. Finally, the summary of sensor optimal placement method generally applied to cable-stayed bridge was made, and the experiment was carried on to confirm the accuracy of the finite element model.