Determining the line weight of an unmarked bamboo rod?

[Korrie]

Wow, a mouth full in a short paragraph. had to read it a couple of times, to try and comprehend it all. still not sure I got it all.
What is the simplest model, load it with enough weight until it breaks?

[smallstreams.co.za]

What is the simplest model, load it with enough weight until it breaks?

I recall that Neil did mention that there is no way to determine this, as there are just too many variables to consider.

If I look at the way bamboo breaks, they never all snap "at once", there is a gradual failure, no matter the time period. Surely with graphite it must be similar. Some fibres will break (not all) untill the remaining fibres cannot carry the load.

[NeilRowe]

I recall that Neil did mention that there is no way to determine this, as there are just too many variables to consider.

If I look at the way bamboo breaks, they never all snap "at once", there is a gradual failure, no matter the time period. Surely with graphite it must be similar. Some fibres will break (not all) untill the remaining fibres cannot carry the load.

Not bad Mario. You listened.

You can overstress and get a break, (obvious).

Or you get gradual degradation over many cycles which results in a slow loss of stiffness (getting papper as Andre so eloquently described it)

A graphite flyrod might never see enough cyclical loading to fail btw.

The way we tested composite tubes was to bend them through 90 degrees and rotate them at about 60rpm with a machine whilst monitoring the tip load. We then plotted a graph of time versus tip load until fracture.

load definitely decreased over time