Date of Award
12-1-2025
Document Type
Thesis
Degree Name
M.S. in Engineering Science
First Advisor
Damian L Stoddard
Second Advisor
Yiwei Han
Third Advisor
Shan Jiang
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
Sandwich composites have emerged as one of the most promising solutions to address the increasing demand for lightweight, high strength protective systems capable of withstanding blast and impact loading. The purpose of this study is to explore the effects of incorporating graphene at 0.1 wt% into the epoxy matrix of a basalt fiber reinforced composite under both quasi-static and dynamic loading for use in lightweight protective sandwich composites, as well as to assess the feasibility of utilizing a 3D printed core design into such a system.
Quasi-static tension, bending, and short beam shear testing was performed, and it was concluded that under tensile loading, the addition of 0.1% graphene increased the stiffness and strength of the material by enhancing the interfacial bonding between the basalt fibers and epoxy matrix. However, under both short beam shear and flexural bending, the strength was decreased. The dynamic behavior was characterized by low velocity impact and Split Hopkinson Pressure Bar (SHPB) testing. There was no significant change observed in the low velocity impact response between composites. Conversely, SHPB testing revealed an increase in compressive strength with the addition of graphene under perpendicular loading and a decrease in compressive strength in parallel loading.
Comparison tests were performed to evaluate the performance of 3D printed core structures with varying geometries and materials under quasi-static compression loading. The PC 2-8 truss core exhibited an average energy absorption of 404 kJ/m³ at 40% strain. The 15% gyroid design exhibited an average energy absorption of 1267 kJ/m3 at 40% strain. Compression testing of aluminum foam samples with varying relative densities revealed an average energy absorption of 1064 kJ/m3 at 40% strain for 10-12% relative density specimens.
Both 2-8 PC truss and 10-12% aluminum foam designs were utilized as core materials with neat basalt composite skins for sandwich system two stage light gas gun testing. The aluminum foam core exhibited a more desirable response with higher energy absorption with respect to deformation. However, it was determined that the use of an additive manufactured core would be feasible with further investigation into core geometries and materials.
Recommended Citation
Key, Auston, "Dynamic and Quasi-Static Characterization of Basalt Fiber Reinforced Graphene Epoxy Composites and 3D Printed Core Systems for Lightweight Sandwich Structures" (2025). Electronic Theses and Dissertations. 3519.
https://egrove.olemiss.edu/etd/3519