Date of Award
Spring 2024
Access Type
Thesis - Open Access
Degree Name
Master of Science in Aerospace Engineering
Department
Aerospace Engineering
Committee Chair
Alberto Mello
First Committee Member
Alberto Mello
Second Committee Member
Sirish Namilae
Third Committee Member
Yizhou Jiang
College Dean
James W. Gregory
Abstract
As the use of composites continues to grow across aerospace, naval, automotive, construction, 3D printing, and other countless industries, so does the desire to continuously improve their mechanical properties. Improving the adherence of the fiber-matrix interface is one important step for amplifying the capabilities of composites. Work has been performed in modifying carbon fibers by growing zinc oxide (ZnO) nanorods in the fiber surface using a hydrothermal approach, increasing interfacial area and fiber-matrix friction. Macroscale evaluation has shown that the interfacial modification decreases the inter-ply movement and reduces the processing strains and residual stresses. To fully understand the mechanism taking place at the interface, a microscale evaluation was conducted to determine the fiber-matrix interaction, analyzing the thermal behavior and cure kinetics due to increase fiber surface area, and improved strength due to increase in interface friction. The proposed approach is to use HD DIC for mapping the interface by using speckles in nanoscale. The speckle pattern was created with Ti nano powder for strain maps in the fiber-matrix interface. The main objective of this research was to develop a protocol for speckling the modified single fiber composite and show that DIC can be used in microscopic level and to evaluate the fiber-matrix interface by means of nano indentation. A comparative analysis of DIC results from ZnO modified carbon fibers has shown that shear strains around the interfacial boundary are 60% reduced on average, as compared to neat carbon fibers, across all nano indentations from 8mN to 65mN of peak load. Results from this study prove that modification by ZnO growth on the surface of individual fibers has a significant benefit to the interfacial mechanical properties of fiber-matrix composites.
Scholarly Commons Citation
Harris, James Matthew, "TI Nano Powder Speckle Pattern Creation and Use in DIC of ZnO Modified Single Carbon Fibers" (2024). Doctoral Dissertations and Master's Theses. 799.
https://commons.erau.edu/edt/799