Effect of Environmental Parameters on Structural Health Status Assessment Using OMA Techniques

Abstract

The data from a laboratory test on two aluminum rods are analyzed in this work. The rods are subjected to environmental excitation in an uncontrolled environment, attempting to replicate real operational conditions of structural health monitoring with external disturbances. Different damage levels are simulated on one of the two tension rods. Three of the most frequently used OMA methods are applied to evaluate the effects of the simulated damage on the dynamic behavior of the system. The complexity of the three applied OMA methods is gradually increased. The difference between the results from the different approaches is assessed. The aim of this work is to assess the performance of the proposed OMA methods, to understand their limits, and to assess the role of environmental disturbance parameters, such as temperature, in the evaluation of the health status of structures.

Keywords

• structural health monitoring
• dynamic monitoring
• operational modal analysis
• peak-picking
• poly-reference least squares complex frequency method
• Cov-SSI