A Sensitivity Based Method for Sensor Placement Optimization of Bridges

摘要

Damage detection is the core technique of bridge health monitoring systems. Mostly, the detection is based on comparison of initial signatures (frequency, mode shapes and so on) of intact bridge with that of damaged bridge. The damage identification technique for bridge structure by vibration mode analysis is based on the precision of modal experiment. In order to identify the damage in time, the problem of sensor placement is very important. The number of the sensors and their settled locations determine the accuracy of test results. So how to distribute sensors reasonably to get the appropriate information about the changes of structure state of the bridge is the key for the health monitoring to large span bridges.Taking an actual long span Bridge as an example and calculating the modal date by the finite element model, a method based on the eigenvector sensitivity, the EI (Effective Independence) method and MAC (Modal Assurance Criterion) method are used to optimize the placement procedure of the sensors in this paper. The numerical example shows that the eigenvector sensitivity based method is an effective method for optimal sensor placement to identify vibration characteristics of the bridges.