Influence of strain rate on the quasi-static tensile strength of Kevlar 29 narrow fabrics
Increasing the strain rate from 3 x 10/sup -4/ min/sup -1/ to 1.4 min/sup -1/ resulted in a 20% increase in fabric strength. Similar changes in strength with strain rate were obtained for warp yarns removed from the fabrics. Static and sliding loop yarn tests, and tests in which yarn was interwoven through wires, were used to determine effect of abrasion, bending and lateral compression as a function of strain rate. Results eliminated yarn damage by abrasion and demonstrated that unwoven yarn strength, in presence of bending or lateral compression, was dependent on strain rate. Yarn and fiber pullout tests showed that increasing strain rate caused a transition from stick-slip to smooth curves. Results suggested a mechanism whereby strain-rate dependent frictional behavior of Kevlar influences woven fabric strength. It appears that friction restrains highly loaded fibers in a fabric from adjusting their position to relieve stress concentrations. Yarn tensile strength is influenced by strain rate when the fiber arrangement has been altered by weaving or when bending or lateral compressive forces are also present.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 5931897
- Report Number(s):
- SAND-81-1226C; CONF-811002-3; ON: DE81030710
- Resource Relation:
- Conference: 7. AIAA aerodynamic decelerator and balloon technology conference, San Diego, CA, USA, 21 Oct 1981; Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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