BayAreaKite wrote: ↑Thu Jan 12, 2023 2:11 am
This is
my last response to this topic. I am not arguing anything, I am giving factual engineering principles and analysis techniques which support my conclusion that this test method is an inaccurate representation of mast loading conditions. Furthermore,
the data that faklord has presented is incorrect because the boundary conditions and lengths used for each mast are different. You are arguing that it is correct, without any engineering analysis or supporting data other than the statement that what faklord has done must be correct because he did it, and I have not.
Secondly, saying an aluminum mast is superior in torsion to a carbon mast is again an inaccurate statement. Aluminum and carbon fiber are materials, and materials are only 1/2 (actually less than 1/2) of the equation for stiffness/strength. The other, and more important influence on structural properties, is design. The shape, the chord length, and thickness. So there are a lot of carbon masts that are way stiffer (in both torsion and bending) than aluminum masts, Project Cedrus being one of them, because of the design (layup, thickness, chord length, etc). Carbon has a much higher modulus of elasticity (stiffness) than aluminum, but if not designed properly, will not necessarily be as stiff in a finished product.
You can learn a lot on my blog. I have a whole post devoted to structural materials and solid mechanics:
https://projectcedrus.com/general/solid ... sites-101/ At some point, I will get around to benchmarking the latest batch of masts, through proper testing/analysis.
I take some issue with statement “the data that faklord has presented is incorrect”:
1) I came across some data from testing that somebody else had presented for various masts.
2) I wondered how the hardware I owned would compare. So I tested it in a similar manner & presented the results.
3) I made it clear that I did not believe the the bending test method was not representative of real use.
For the
intended purpose (Ie comparison with previous tests) I believe the data to be correct.
If anybody has issue with (& can correct) the analysis I did to compensate for different lengths, I’d be interested to hear but I’m won’t be interested to just hear “it’s wrong”
I will be attempting to test the hardware I own (gong alu v2 85 & 70cm, gong carbon 85cm, & Project Cedrus 90cm) using an “eccentric column loading” test method in the near future…