Analysis of metals used in gyroplanes

[Learjet]

One often hears interesting (and differing opinions) about what metals are best suited (or indeed unsuitable) for (relatively high-vibration) gyro manufacturing applications and I came across an interesting analysis of typical metals used in gyroplanes construction on another forum which I thought I'd tabulate for comparison.
I'm not a rocket science when it comes to metallurgy and used wiki definitions for the properties descriptions to help me understand the dynamics - but I would welcome insights from those with more knowledge and a better understanding of the pros and cons of using these various metals in gyro manufacture. It would also be interesting to know how carbon-fibre compares given the new generation of C-f monocoque machines, and an Oz company has recently started building gyros using a titanium airframe (at what cost ?? ).

I appreciate that in aviation there is always a compromise to be made with regards "functionality versus weight versus cost" so there probably isn't an outright "perfect metal winner" but it would be interesting to get an idea of what works best where?

[MPL Pilot]

It would also be interesting to know how carbon-fibre compares given the new generation of C-f monocoque machines,

I am no guru on material strengths, always had a n interest in it and learned a lot during the certification of the UFO.
This would give an indication of carbon fiber strength.
http://www.performance-composites.com/c ... ties_2.asp

It would be necessary to make up a model and test it for performance and keep the same molding in layers ect. for production.

For peace of mind I did a few of my own tests at work, shearing bolts and stretching various materials to measure the deformation and break points.
It was very interesting, our gyro's are built very well and over engineered in many places.

Will post some pictures of stress analysis that I have done on Autodesk Inventor, comparing aluminum and titanium.

[MPL Pilot]

A simple bracket as in the picture

Material: Allum 7075 : Tatinuim
Weight : 0.02kg : 0.033kg
Load : 1000kg : 1000kg/1500kg
Displacement : 0.11mm : 0.079mm/0.11mm

Very interesting, for 0.013kg extra titanium can take 50% more load to have the same displacement as aluminum

[THI]

Pierre, we need to organize a north meets north so that we can talk this over over a fire and a braai.

Very interesting!

[Baitbird]

Pierre
How did the software results compare to your actual shear / stress tests?

Bb

[MPL Pilot]

Pierre, we need to organize a north meets north so that we can talk this over over a fire and a braai.

Very interesting!

Sounds like a good idea, like I said, I am no guru with material strengths ect, found it fascinating to do tests of my own.
I wanted to know if the mast, hang bolt, hub bar, cheek plates, and bolts keeping every thing together, was up to the job with the weight of the UFO, taking into account thermals giving bumpy rides, I found
that the materials used was at least 3X stronger than the ultimate load placed on the structure at the weakest point.

How did the software results compare to your actual shear / stress tests?

I found that the parts tested did not "break" at the point Inventor suggested failure, but with up to 20% more load.
It could be the setup I used for tests, or that they have a safety factor build into their calculations. There could be unknown factors involved, but I
know I am safe flying the UFO with the results obtained.

Another test was to check the "Teeter Bolt" up to break point, it is a 3/8 AN Bolt, It snapped at 9600kg
There is no way that a gyro of 700kg will exceed a safety factor of 13!!

We can fly with confidence, the guys with the thick glasses know what they are doing

Have fun