Numerical analysis of Long Period Grating Fibre Sensor operational characteristics as embedded in polymer

The paper main purpose is to present the results obtained in development of a LPGFS (Long Period Grating Fibre Sensor) embedded into a polymer composite simulation model. In this way the polymer composite transforms into a “smart one”. The developed simulation model is a “must be accomplished” stage for a proper manner engineering the smart polymer composite materials fabrication and for improved designs of their applications in various fields such as aeronautics, chemical industry and defence. A LPGFS is operated by observing the spectral shifts, broadenings and splitting of its Bragg resonance absorption bands appearing into its transmission spectrum. The developed simulation model of the LPGFS embedded into a polymer composite must cover basically the modification of its transmission spectrum caused by polymer refractive index characteristics, firstly with no applied mechanical loads and secondly by considering the mechanical stress induced in the optic fibre by the polymer embedment. The LPGFS simulation model is developed considering the role of optic fibre birefringence induced by polymer embedment. After that, it follows the specific application stage in which it is analysed the LPGFS response to loads applied to smart composite material by its environment.