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Statistical analysis of fiber gripping effects on Kolsky bar test



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


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


soft body armor, single fiber, Kolsky bar, statistics


, 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], (Accessed February 22, 2024)
Created June 14, 2011, Updated February 19, 2017