Investigating the use of Polarization maintaining FBG sensors for GW based SHM

Guided waves (GWs) are very popular for the damage detection of thin-walled structures. They propagate large distances and relatively few may be used for damage localization. The problem with their use for complex structures is the signal processing. Due to the presence of multiple modes, and mode conversion and reflections from the structure boundaries and discontinuities the signal processing is indeed challenging. In order to reduce the complexity, lower frequencies are used to limit the excitation only to the fundamental modes. Even then the signal processing may be challenging. So efforts are focussed on the ability of some sensors to detect only a particular wave. This paper aims at investigating the suitability of the polarization maintaining FBG (PM-FBG) for this purpose.