Dynamic Body Armor Shape Sensing Using Fiber Bragg Gratings and Photoassisted Silicon Wire-EDM Machining

In this thesis, a method to improve survivability is developed for fiber Bragg gratings under high velocity impact in dynamic body armor shape sensing applications by encasing the fiber in silicone. Utilizing the slipping of the fiber within the silicone channel, a proportionality relationship betwe...

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Bibliographic Details
Main Author: Velasco, Ivann Civi Lomas-E
Format: Others
Published: BYU ScholarsArchive 2021
Subjects:
Online Access:https://scholarsarchive.byu.edu/etd/9201
https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=10210&context=etd
Description
Summary:In this thesis, a method to improve survivability is developed for fiber Bragg gratings under high velocity impact in dynamic body armor shape sensing applications by encasing the fiber in silicone. Utilizing the slipping of the fiber within the silicone channel, a proportionality relationship between the strain of the fiber to the acceleration of the impacting projectile is found and is used to obtain the rate of the back-face deformation. A hybrid model is developed to handle errors caused by the stick-slip of the fiber by fitting an inverse exponential to stuck sections found in a captured strain profile and double integrated to transform the stuck section to its equivalent slipping. Displacement errors below 10% was achieved using the hybrid model. A graphical user interface with a step-by-step walkthrough and a fiber Bragg grating interrogation system was designed for test engineers to utilize this technology. Test engineers from the Army Test Center in Aberdeen, MD were trained on this technology and successfully captured and processed shots using this technology. A method for cutting Silicon through wire-EDM machining is developed by utilizing the photoconductive properties of Silicon. Cut rates for unilluminated and illuminated Silicon was compared and a 3x faster cut was achieved on the illuminated cuts.