Distribution modal identification based on stochastic subspace method

For large-scale civil structures, the rich information can be harvested from a dense array of sensors. This is a big challenge for centralized processing technique. A distributed method to obtain modal parameters in smart sensor networks (SSN) with a dense array of sensors is proposed. Using a concrete-filled steel arch bridge as a testing model, Stochastic subspace identification is implemented to identify local modal parameters from ambient vibration response for the different subgroups cases. Stabilization diagram is a novel approach to define the rank of the system while get rid of noisy modes. Global mode shape is combined from rescaled local mode shapes through particle swarm optimization and average method. The results show that it enjoys a better efficiency according to modal assurance criterion (MAC). This distributed method can be applied to any other complicated structures to determine modal parameters.