Error Reduction for the Determination of Transverse Moduli of Single-Strand Carbon Fibers via Atomic Force Microscopy

Author

Joshua D. Frey

Date of Award

3-2021

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Abigail A. Bickley, PhD

Second Advisor

Nicholas Herr, PhD

Abstract

The transverse modulus of single strand carbon fibers is measured using PeakForce Atomic Force Microscopy - Quantitative Nanomechanical Measurement to less than 5 percent error for 11 types of carbon fiber with longitudinal moduli between 924-231 GPA, including export-controlled fibers. Statistical methods are employed to improve the quality of data to exclude outliers within an measurement and within the sample set. A positive linear correlation between the longitudinal and transverse modulus with an R²=0.76 is found. Pitch-based fibers exhibit lower measurement error than PAN-based fibers, while PAN fibers exhibited no apparent modulus correlation when the Pitch fibers are excluded. Three alternative methods for calculating the transverse modulus using the raw instrument data were studied. Two methods approximated the indentation force curve, while the third performs a linear fit to the measured force curves.

AFIT Designator

AFIT-ENP-MS-21-M-115

DTIC Accession Number

AD1146026

Recommended Citation

Frey, Joshua D., "Error Reduction for the Determination of Transverse Moduli of Single-Strand Carbon Fibers via Atomic Force Microscopy" (2021). Theses and Dissertations. 5036.
https://scholar.afit.edu/etd/5036