Dynamic strain analysis with micro-structured fiber optic strain sensors embedded in structural components

Abstract

In my Master thesis, we bombine the potential of fiber Bragg gratings (FBGs) and microstructured optical fibers (MOFs) into microstructured optical fiber Bragg grating (MOFBG) sensors. These innovative sensors enable 3D strain measurements once embedded inside a carbon fiber reinforced polymer (CFRP) composite material. The main goal of the thesis was to demonstrate the ability to perform dynamic strain measurements with these embedded MOFBG sensors for the first time. To do so, we made measurements of the MOFBG spectrum when the composite plate with the embedded sensors was exposed to an impact on its surface and we processed the reflection spectra with an innovative peak detection algorithm. With this approach we were able to detect and quantify the three-dimensional strain field in the composite plate during impact. Additionally an interrogator based on a VCSEL, with the potential of being miniaturized and produced at low-cost, was shown to be able to carry out full-spectrum measurements of the MOFBG reflection spectrum for the first time.

Date of Award	2015
Original language	English
Supervisor	Thomas Geernaert (Promotor) & Alfredo Lamberti (Promotor)