Structural modal identification based on distributed wireless smart sensor networks

Abstract

This paper presents the vibration test of a simply supported plywood plate using ISM400 wireless smart sensor developed by the Illinois Structural Health Monitoring Project(ISHMP).Decentralized data aggregation(DDA)as well as centralized data collection(CDC)was used for data acquisition and processing.Then a time domain algorithms integrating natural excitation technique(NExT)and eigensystem realization algorithm(ERA),was applied to identify modal parameters of the plate and the identification result was compared with the finite element result.The modal parameters(i.e.natural frequency and mode shape)identified from experimental data using DDA is not only in accordance with that using CDC,but also in accordance with the numerical simulation result,which shows that the wireless smart sensor networks(WSSN)based on DDA is reasonable and effective.Compared with conventional centralized processing technique,the unique features offered by distributed WSSN,including high integration and electrical energy saving,make deployment of a dense array of sensors on large civil structures both feasible and economical.