Combined fiber Bragg grating and fiber optic polarimetric sensors on a single fiber for structural health monitoring of two-dimensional structures

Fiber optic sensors have a lot to offer in the field of structural health monitoring. The most widely investigated and implemented fiber optic sensors for structural health monitoring are fiber Bragg grating and fiber optic polarimetric sensor. Fiber Bragg grating sensors provide localized strain data, thereby providing local damage information, while fiber optic polarimetric sensors are known for their capabilities of global damage monitoring for both static and dynamic loadings. However, each sensor has to be used with its own instrumentation and processing system. In this article, it is shown that an fiber Bragg grating written on a polarizing maintaining fiber can discern information from both fiber Bragg grating and fiber optic polarimetric sensors using only one decoding system. This reduces costs and complexities. Furthermore, by proper multiplexing the polarizing maintaining-fiber Bragg grating sensor, it is possible to predict the damage location in plates. The results demonstrate that the damage site can be located in two-dimensional structures using this multiplexed sensing array.