Dynamic modulus and strain wave velocity in ballistic fibre strands
- 203 Downloads
Strain wave propagation velocity in fibre materials is a primary consideration in the design of body armours for ballistic protection. In this paper, we compare the strain wave propagation (sonic) velocities and moduli of parallel and twisted ballistic fibre strands (yarns) derived from quasi-static tensile test and strain wave pulse test. In parallel multifilament yarns, the individual fibres behave independently from each other, and the yarn sonic velocities and moduli derived from the two test methods match each other very closely. In yarns with a twisted structure by twisting multifilament yarn or by spinning short fibres, fibres in the yarns are compressed against each other and fibre-to-fibre friction plays a significant role. Consequently, the yarn sonic velocities and moduli determined by the strain wave pulse method are significantly greater than that derived from the quasi-static tensile method.
KeywordsUltrahigh Molecular Weight Polyethylene Sonic Velocity Strain Wave Staple Fibre Specific Modulus
This work was conducted within the Defence Materials Technology Centre, which was established and is supported by the Australian Government’s Defence Future Capability Technology Centre (DFCTC) initiative. Jill McDonnell carried out some of the strain wave pulse propagation tests on the twistless multifilament yarns. Badar Zaidi conducted the single-fibre tests on Favimat fibre tensile testing machine.
- 3.Cavallaro PV (2011) Soft body armor: an overview of materials, manufacturing, testing, and ballistic impact dynamics. DTIC Document, New YorkGoogle Scholar
- 9.Cunniff PM (1999) Dimensionless parameters for optimization of textile-based armour systems. 18th international symposium on Ballistics, 15–19 November 1999, San Antonio, pp 1303–1310Google Scholar
- 21.Hearle JWS, Grosberg P, Backer S (1969) Structural mechanics of fibers, yarns, and fabrics. Wiley-Interscience, New YorkGoogle Scholar