Statistical analysis of fiber gripping effects on Kolsky bar test

Published

June 14, 2011

Author(s)

Jae Hyun Kim, Nathanael A. Heckert, Stefan D. Leigh, Haruki Kobayashi, Walter G. McDonough, Richard L. Rhorer, Kirk D. Rice, Gale A. Holmes

Abstract

Preliminary data for testing fibers at high strain rates using the Kolsky bar test by Ming Cheng et al. 1 indicated minimal effect of strain rate on the tensile stress-strain behavior of PPTA, poly (p-phenylene terephathalamide) fibers. In a different study, Lim et al.2 reported that the tensile strengths of the copolymer aramid fibers are strain rate dependent. Usually with single fiber tests, a large sample population is needed to get statistically significant results. To date with high strain rate tests, technical issues associated with specimen preparation appear to limit the number of samples that can be tested within a reasonable time. In this study, the authors investigate the feasibility of a new gripping design in order to ultimately establish a reliable, reproducible, and accurate Kolsky bar test methodology for single fiber tensile testing with high throughput. Preliminary results performed under a quasi-static strain rate with 5 mm and 60 mm gauge lengths showed that the PPTA fibers are gauge length dependent. This gripping and size effect must be considered in determining the true strain rate effect on fiber strength.

Proceedings Title

Experimental Mechanics in the Age of Modeling and Simulation

Conference Dates

June 13-15, 2011

Conference Location

Uncasville, CT

Conference Title

2011 SEM Annual Conference and Exposition on Experimental and Applied Mechanics

Pub Type

Conferences

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Keywords

soft body armor, single fiber, Kolsky bar, statistics

Citation

, J. , Heckert, N. , Leigh, S. , Kobayashi, H. , McDonough, W. , Rhorer, R. , Rice, K. and Holmes, G. (2011), Statistical analysis of fiber gripping effects on Kolsky bar test, Experimental Mechanics in the Age of Modeling and Simulation, Uncasville, CT, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=908102 (Accessed October 11, 2025)