Abstract
This paper reports on an experimental investigation into the differences between directly and remotely bonded optical fiber Bragg grating (FBG) sensors when measuring Lamb waves in an aluminum plate. A sensor array, comprising 16 individual short gauge-length FBG sensing elements, is used to decompose the wave into its constituent modes for the directly bonded case, where the array is attached directly to the plate and for the remotely bonded case where the same array is located in a suspended fiber 250 mm downstream from the fiber/plate contact region. The experimental results were consistent with model predictions and show that while the directly bonded fiber array can resolve the full multimodal Lamb wave spectrum in the plate, the remotely bonded sensor measures only a single nondispersive longitudinal acoustic mode predicted by the analytical solution for a cylindrical waveguide. The inability of remote sensing to distinguish between different modes of Lamb wave propagation represents a significant limitation with respect to the diagnostic utility of this sensing approach.
© 2018 IEEE
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription