Error Reduction for the Determination of Transverse Moduli of Single-Strand Carbon Fibers via Atomic Force Microscopy
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 25, 2021
- Accession Number
- AD1146026
Entities
People
- Joshua D. Frey
Organizations
- Air Force Institute of Technology