LESSON 8.4 · 1:44 · CHAPTER 8 · TESTING, TANKS AND WHAT'S NEXT
Autofrettage
In a metal-lined (Type III) vessel, one deliberate overload yields the liner; when the pressure comes off, the still-elastic composite squeezes the stretched liner, leaving it in compression at zero pressure. In service the liner then cycles from compression to tension, at lower peak stress, and lasts longer in fatigue.
Predict · at 0:31 in the video
Now take the pressure off. At zero pressure, is the liner in tension, in compression, or stress-free?
Compression. The carbon wants to spring back to its old size. The liner is now too big for it.
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 · 8.5 · 2:06Hydrogen at 700 bar