Impact Statement:The design of uniform Fiber Bragg Gratings, written in Polarization-Maintaining fibers embedded in Carbon Reinforced Polymer and covered between two Adhesive Polyimide Fi...Show More
Abstract:
Uniform Fiber Bragg Grating sensors based on Polarization-Maintaining fibers are designed for simultaneous longitudinal strain and temperature measurement of Carbon Fiber...Show MoreMetadata
Impact Statement:
The design of uniform Fiber Bragg Gratings, written in Polarization-Maintaining fibers embedded in Carbon Reinforced Polymer and covered between two Adhesive Polyimide Films (APFs), is performed. The optomechanical simulations suggest that suitable APFs embedding the polyimide coated optical fibers allow a more accurate strain and temperature measurement with respect to uncoated or polyimide coated optical fibers without APFs, with a temperature sensitivity increase of about 10%
Abstract:
Uniform Fiber Bragg Grating sensors based on Polarization-Maintaining fibers are designed for simultaneous longitudinal strain and temperature measurement of Carbon Fiber Reinforced Polymer laminates. Panda, Bow tie and Pseudo-rectangle optical fiber shape sections are investigated employing three different embedding methods, for each optical fiber. The simulation accurately takes into account that the fibers are embedded in unidirectional Carbon Fiber Reinforced Polymer and covered between two adhesive polyimide films. An exhaustive, accurate and robust investigation of the mechanisms originating Bragg wavelength shift is developed by considering a complete multiphysical model including: the propagation modes and their interaction, the birefringence, the optomechanical and thermal behaviour of both the optical fiber and the embedding composite material. For the first time, the use of polyimide films is proposed to obtain an increase of temperature sensor sensitivity, reducing the stress-transfer, due to thermal expansion, between the composite laminate and the sensing element. The designed Fiber Bragg Grating sensors are compared and their potential application, for simultaneous strain and temperature measurement of Carbon Fiber Reinforced Polymer is discussed.
Published in: IEEE Photonics Journal ( Volume: 13, Issue: 2, April 2021)