Research On Wireless Distributed Monitoring System For Engineering Structure

With the development of long-span structure and super high-rise building, academic field and civil engineering field is laying increasing emphasis on study and application of structural health monitoring (SHM). As for large-scale structure SHM, according to wireless distributed data acquiring, zoning and layered processing, this paper studies its system structure and monitoring methods. Based on design of experimental monitoring system, there goes the study on the following critical methods of wireless distributed SHM practical application in engineering field: synchronous sampling, energy balancing, optimal sensor locating, structural modal parameter identifying, and structural local damage identifying.1. In this paper, it analyzes characteristics and advantages of wireless distributed SHM on the basis of large-scale SHM function. It designs structure of wireless distributed SHM system based on wireless distributed data acquiring, zoning and layered processing. It studies methods of wireless distributed SHM with its specialty of long-term and online monitoring. It develops wireless sensing key components of solar power supply. It creates experimental distributed SHM system with GPS synchronization and wireless sensor networks (WSN) two-stage synchronization. And it tests and proves the performance of experimental components.2. In this paper, as for wireless distributed SHM synchronous sampling, it indicates a step by step synchronization mechanism and ensures clock difference between each node less than 50us. It analyzes distributed WSN energy balancing mechanism of structural local and overall monitoring. And it proves the accuracy of routing algorithm for subnet energy balancing.3. In this paper, as for large-scale structure using wireless distributed sensor networks identifying structural modal parameter, it divides long-span structure into series sub-structure and parallel by local identifying and overall identifying. As for wireless sensor nodes locating, it proposes optimal locating method. And with finite element method, it optimizes sensor location of 1st bridge of Wuhan University of Technology and proves its validity. 4. In this paper, as for complicated large-scale structure, with local damage identification of wireless distributed sensor networks, it created a local damage identification method based on EMD and NARX neural network. It gets structure parameter by observing sub-structure response and proves feasibility of indoor experiment.