Research On WSN-based Energy-efficient Method Of Building Structure Modal Analysis

With the development of wireless sensor network (WSN) and building structural health monitoring (SHM), WSN-based building SHM system has become the research hotspot of many researchers in recent years. Wireless sensor nodes are usually powered by battery when applied in building SHM situation and the nodes will die if not charged, therefore, energy becomes the key factor of system performance. For the energy consumption of WSN-based building SHM system, an energy-efficient modal analysis method is realized to reduce intra-cluster traffic and energy consumption under the architecture of cluster-based SHM system, and a clustering method which applies to identifying mode shape is also proposed to reduce system energy consumption based on the characteristics of the mode shape.Cluster-based building SHM system architecture can help get accurate modal parameters with low energy consumption. A cluster-based joint NExT-ERA energy-saving modal analysis method is presented in this thesis to improve existing methods under the architecture of cluster-based SHM system. The improved method optimizes the joint NExT-ERA modal analysis method by designing reasonable intra-cluster communication strategy. Simulation results show that the method can effectively decrease intra-cluster energy consumption by reducing intra-cluster data traffic, thereby reducing energy consumption of the system.Mode shape is more sensitive to structural damage compared to natural frequency. The obtaining of structural overall mode shape needs to integrate local mode shape of each cluster under the architecture of cluster-based SHM system. A WSN overlapping clustering based on structural mode shape identification method is proposed considering the characteristics of mode shape. Wireless sensor nodes installed in the structure are divided into several overlapping clusters, and then the cluster-based joint NExT-ERA energy-saving modal analysis method is used to identify the local mode shape. Finally, overlapping technology is used to integrate the local mode shape of each cluster, and the complete structure mode shape can therefore be obtained. Simulation results show that the method can not only guarantee the accuracy of the mode shape but also reduce the energy consumption of the system significantly.