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Variability Characteristics of Structural Health Monitoring Data and Development of Engineering Report Tool. Nicolás A. Londoño David T. Lau Department of Civil & Environmental Engineering Carleton University Ottawa, Canada. SAMCO Summer Academy Zell am See, Austria Sept 5-9, 2005.
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Variability Characteristics of Structural Health Monitoring Data and Development of Engineering Report Tool Nicolás A. Londoño David T. Lau Department of Civil & Environmental Engineering Carleton University Ottawa, Canada SAMCO Summer Academy Zell am See, Austria Sept 5-9, 2005
Overview • Introduction • Computer Tools • Research using Confederation Bridge field monitoring data • Design properties verification • Variability of monitoring data • Engineering Report Tool • Conclusions
Monitoring System Data logger LAN Sensors On Site Computers Internet Carleton University Processing • Analysis (System Identification) • Frequency • Mode-shape • Damping ratios Condition Assessment Engineering Reporting and Interpretation
Data characteristics Wind scenario Traffic scenario 40 seconds 600 seconds
Wind scenarios Traffic scenarios
Stochastic Subspace Identification State Space model Output-only monitoring data Singular Value Decomposition Data cross-correlations Stochastic State-Space Model Matrices Block Toeplitz Matrix Frequencies Mode Shapes Damping Ratios
SPPLASH – Signal Processing PLatform for Analysis of Structural Health
Identified 2.76 Hz Theoretical 2.59 Hz MAC 0.89
Variability-Sources- • Numerical uncertainties • Deviation from model assumptions • Data non-stationarity • Non-whiteness of the inputs • Measurement noise • Computational uncertainties • Use of finite datasets • Analyst input • Physical Uncertainties • Environmental and loading fluctuations • Temperature effects • Bridge-vehicle coupling, etc.
Temperature Effect Modal Frequency (Hz) Temperature (Hz)
Engineering Report Tool • Motivation • Enhance feedback given to bridge owners and operators • Provide timely systematic information of engineering relevance for decision support • Requirements • Automated file sorting and processing • Easy to search database
Confederation Bridge Monitoring Data • Truck Traffic induced vibration • Wind storm (Nov. 7 2001) • Typical ambient vibration