Big things are weaker
Fibre strength is set by its weakest flaw, and the more fibre under stress, the likelier a bad flaw: strength falls from strand to laminate to vessel (Weibull size effect). A vessel's hoop layer typically delivers well below the strand strength; we use about 80 %, as in lesson 1.2.
Predict · at 0:36 in the video
Strand strength 5.5 gigapascal. Roughly what does the hoop layer of a vessel deliver?
Something like a fifth less. That's the 80 percent we assumed back in lesson 1.2, and it's in the range the literature reports. How much exactly depends on the fibre, the resin and the process.
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
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.
