hi

does anyone have answer to how to define nr. of layers to obtain desired strength of object.

i would like to do seat post tube for my MTB.
so how to define what would be the minimum amount of layers that tube will still support my weight and not to have too much of not needed weight.

i know there is no 100% accurate way, but at least a point to start

i agree with Hanaldo.
its no point of putting all that work to make same weight part as metal. but thanks David for answer.

and as i read is kevlar only crack arrestor. and if not cured at exact right temperature it doesn't bond. so i think i will skip it.

i was thinking kinda a same direction. same thickness. but if i would like to go more extreme.
carbon fiber have twice the strength as aluminum.
so in theory it can be halve the thickness of alu ? of course its not that simple...
and of course depends on layup and type of fabric.