LESSON 8.1 · 1:48 · CHAPTER 8 · TESTING, TANKS AND WHAT'S NEXT
A ring is the purest test
A hoop-wound ring loaded by internal pressure carries pure hoop tension, so it reads the fibre's real strength. The split-disk test (ASTM D2290 style) loads the ring through two half-discs; at the split the ring bends, and it fails early there, reading low.
Predict · at 0:36 in the video
Split disk, or pressurised ring: which one reads the higher strength?
The pressurised ring. At the split, the ring isn't supported, so it bends there as well as stretching. Bending on top of tension, and it breaks early, right at the split.
Further reading
This course is our own. These books go deeper.
- Composite Filament Winding, S. T. Peters (ed.), ASM International, 2011
- Filament Winding: a Unified Approach, S. Koussios, Delft University Press, 2004
About the numbers
Simulations in this lesson are our own. Where a number rests on an assumption, the video marks it with an asterisk and says where it comes from.
Up next · 8.2 · 1:53Big things are weaker