Flexural fatigue is a critical concern in many applications where yarns or fabrics are subject to repeated bending or creasing. Examples include ropes, sailcloth, inflatable and/or temporary structures, etc. Improving the service life of products by increasing flex fatigue resistance is an important driver for the use of VECTRAN™ fibers.
Fatigue testing of coated fabrics
Base Material | Tenacity Loss at Failure Location 100 Cycles, % | Failure Location |
---|---|---|
VECTRAN™ | 0.8 | Away from fatigued crease |
Aramid | 22.9 | At crease |
Flex fatigue results on 1500D yarn
Material | Cycles-to-Failure |
---|---|
VECTRAN™ T97 | 115113 |
Aramid 1 | 5114 |
Aramid 2 | 40666 |
Aramid 3 | 1383 |
PBO | 23821 |
Test Conditions: Tinius Olsen tester, ASTM D2176-97a, modified for yarn, 4.5 lb weight.
Flex fatigue results on 2 mm cords
Material | Cycles-to-Failure |
---|---|
VECTRAN™ T117 | 41909 |
Aramid 1 | 2115 |
Aramid 2 | 14963 |
Aramid 3 | 8143 |
PBO | 25158 |
Construction: Parallel core/extruded jacket.
Test conditions: 45 mm diameter pulley, 45 kg test load, 58 cycles/min., 5 tests/sample on cyclic test machine.
Bend Tolerance
Tolerance to bending around small radii is important in ropes and cables, as it allows the use of smaller running gears or termination hardware. Aerospace and rope manufacturers conducted pin diameter tests on Vectran™ braid and wire rope, respectively.