Development of energy absorption structures based on carbon nanofiber foams and shear thickening fluids
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Authors
Dominguez, Charliean
Subjects
Carbon nanofiber foam fabrication
shear thickening fluids
rheology
strengthening
energy
absorption
mechanical testing and characterization methods
shear thickening fluids
rheology
strengthening
energy
absorption
mechanical testing and characterization methods
Advisors
Luhrs, Claudia
Date of Issue
2016-06
Date
June 2016
Publisher
Monterey, California: Naval Postgraduate School
Language
Abstract
The objective of this thesis was to engineer multifunctional nanostructures, based on carbon nanofiber
foams (CNFF), to improve their energy absorption. To attain the goal, experimental research was
conducted that combined the CNFF with a) commercial carbon frameworks and b) silica nanoparticles or
fumed silica, dispersed on ethylene glycol, forming shear-thickening fluids (STF). The latter were used to
fabricate core-shell structures in which the CNFF-STF served as a core and epoxy resin was used as the
shell.
The individual nanofibers were characterized by scanning electron microscopy (SEM) and energy
dispersive spectroscopy (EDS) methods while the STF rheology was examined as a function of the strain
rate. The mechanical properties of the CNFF-STF specimens and the core-shell composites were
determined through cyclic compression and hardness measurements/impact tests, respectively.
It was found that the CNFF/commercial frameworks combination generated structures that were too
brittle for the desired application. However, the combination of CNFF-STF encased by an epoxy layer
resulted in core-shell structures with significant improvements in energy absorption, up to 140% higher
when compared to bare epoxy and 33% better when compared to CNFF/epoxy.
Type
Thesis
Description
Series/Report No
Department
Mechanical and Aerospace Engineering (MAE)
Organization
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.