Revealing statistically robust strain rate effects on mechanical performance of pristine single fiber aramids

Published

August 10, 2026

Author(s)

Atik Faisal, Alexander Landauer, Walter Adamy, Dumbari Kabari, Kathleen Lamkin-Kennard, Amanda Forster, Amy Engelbrehcht-Wiggans

Abstract

High-performance synthetic fibers, especially aramid fibers, are widely used for body armor applications for their strength, stiffness, and excellent strength-to-weight ratio. Among those, Kevlar and Twaron (hereafter Aramid A and Aramid B, respectively) are extensively used for their superior thermal stability, high modulus, and proven ballistic performance. However, their tensile behavior under high strain rate (HSR) conditions approaching ballistic impact rates remains insufficiently characterized due to experimental challenges in measuring stress and strain at break at the single-fiber level. Previous studies have suggested moderate strain rate sensitivity in aramid-based fibers, but small sample sizes and limited accuracy in failure strain measurement under HSR have constrained the statistical robustness of the findings. In this study, a custom single-fiber tensile Kolsky bar instrument was configured for HSR tensile testing with accurate specimen alignment, gripping, and pulse quality. A rigid-body digital image correlation (DIC) method was implemented to track relative grip displacements and measure the strain at failure, enabling accurate measurements of failure force, strain, and strain rate at the single-fiber level. Using 62 samples per fiber at HSR and 100 per group under quasi-static (QS) conditions, clear strain-rate-dependent strengthening was observed in both fiber types. Maximum force, failure stress, and failure strain increased by approximately 28.5 % to 35.6 % under HSR compared to QS. The large sample size enabled a statistically robust assessment using distributional and non-parametric analyses, showing that Aramid B exhibited more uniform failure distributions than Aramid A. The approach establishes a practical framework for quantifying single-fiber strain-rate sensitivity.

Citation

Journal of the Dynamic Behavior of Materials

Volume

326

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.compositesb.2026.114059

Local Download

Keywords

Aramid fibers, Tensile testing, Strain rate sensitivity, Kolsky bar, High strength fiber, Body Armor, High strain rate

Citation

Faisal, A. , Landauer, A. , Adamy, W. , Kabari, D. , Lamkin-Kennard, K. , Forster, A. and Engelbrehcht-Wiggans, A. (2026), Revealing statistically robust strain rate effects on mechanical performance of pristine single fiber aramids, Journal of the Dynamic Behavior of Materials, [online], https://doi.org/10.1016/j.compositesb.2026.114059, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=962038 (Accessed August 12, 2026)

Additional citation formats