8. On the Selection of Mode Shapes Used in Optimal Sensor Placement

Structural health monitoring (SHM) is gaining more attention, particularly for bridge structures to continuously evaluate their structural performance and assure their serviceability and safety throughout their service life. To assure reliable SHM systems, optimal sensor placement (OSP) is a cornerstone since it directly influences the quality of obtained data and, thus, the accuracy of the diagnosis. Hence, determining the optimal sensor configuration is a critical step to acquire the maximum information on the structural behavior. Of the available OSP methods, the effective independence method (EFI), which aims to assure that the mode shapes identified from the recorded vibrations are orthogonal to each other, is popular and widely used in literature. Despite its popularity, there are no clear guidelines on how to select the modes that will be included in the OSP application. This chapter evaluates the impact of various parameters including the selected number of mode shapes and sensors on the results of OSP using EFI.