A Smart Wireless Sensor Network for Structural Damage Detection

The real virtue of a wireless sensor network is the fact that it is a new sensing paradigm offering distributed data processing capacity, which can be used for structural health monitoring. For this purpose, a smart wireless sensor network is established for autonomous structural damage detection in this paper. The designed wireless sensor network has a two-level cluster-tree architecture. Distributed sensors are grouped into clusters in which a cluster head is assigned to each cluster to coordinate the sensors in its cluster. Hardware designs of the sensor unit and the cluster head are studied, especially the cluster head consists of a low power DSP with strong computing capacity. Thus, the wireless sensor network provides distributed computation resources at group level. Then, an algorithm for distributed structural damage detection with limited input and output measurements is proposed. A large size structure is decomposed into smaller substructures based on substructure approach. Inter-connection effect between adjacent substructures is considered as ‘unknown inputs’ to substructures. Element level structural parameters and the unknown inputs in each substructure are identified by a two step Kalman estimator and least-squares estimation approach to save computational power and storages. Finally, the proposed algorithm is embedded into the designed wireless sensor network, which grants the network with “smart” characteristics. The smart sensor network is experimentally verified by application to detect structural damage of a multi-story building. It is shown that it is effective for autonomous detection of structural damage.