Fabrication and characterization of electrospun polyacrylonitrile carbonized fibers as strain gauges in composites for structural health monitoring applications
Abstract
This dissertation is aimed at developing new materials to be used as strain gauges in
structural health monitoring (SHM) of composite aircraft structures. The unabated growth in air
traffic has spurred increased demand in the aerospace industry to manufacture reduced-cost
aircraft that are efficient to operate, friendly to the environment, and have an adequate level of
safety. Due to their easy manufacturing process and high performance, carbon-based
piezoresistive sensors, such as carbon nanotubes, graphite, and graphene, have been developed as
alternatives to the traditional silicon/metal-based microelectromechanical system (MEMS), with
applications ranging from industrial to medical fields. These sensors can be used in in-situ SHM
industries and prosthesis applications because of their small size and high sensitivity to small
forces. The detection of flaws and monitoring on a continuous and routine basis is the motive
behind SHM devices. Nanomaterials play an remarkable role in the development of
nanotechnology. Carbon nanofibers have high strength and stiffness as well as unique thermal
and electrical properties. The primary precursor used for the bulk production of carbon
nanofibers is polyacrylonitrile (PAN). The most promising technique for the synthesis of carbon
nanofibers is electrospinning, with PAN as the main polymer precursor. This dissertation deals
with the fabrication of PAN-derived fibers via electrospinning followed by stabilization and
carbonization in order to remove all non-carboneous materials and ensure pure carbon fibers as
the resulting material. Prepared nanofiber films were placed on pre-preg composites and cocured
in a vacuum oven. The basic aim of this study was to fabricate lightweight and costeffective
PAN-derived electrospun fibers for SHM applications of composites and test them for
durability under different conditions.
Description
Thesis (Ph.D.)-- Wichita State University, College of Engineering, Dept. of Mechanical Engineering