Sizing a wall in sixty seconds
Netting analysis turns pressure, radius and fibre strength into a helical and a hoop thickness with a pencil: t_helical = PR / (2σ cos²α), and the hoops carry the rest, t_hoop = (PR / 2σ)(2 − tan²α).
Predict · at 1:21 in the video
Now build the same tube from high-strength steel at 1000 megapascals, to the same burst pressure. Per square metre of wall, how much lighter is the carbon: two times, four times, or eight times?
Close to eight. Steel needs P R over its strength: 4.5 millimetres. At 7.85 grams per cubic centimetre, that's 35 kilograms per square metre.
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.
