Will trade a whole CD full of cad files for an FEA on this 30 mm wide steel ring.

The 40 mm dia. steel rollers exert a force of 2000 pounds or 900 Kg radially outward. I also would like the contact stresses as well if possible.

The Rockwell hardness is C64.

BTW does anybody know of any affordable FEA software?

Paul Lamar ...No rotor no motor.

Give me the modulus for each of the materials. The thickness would help as
well. There will be edge effects.

You can do this simple geometry by hand and get quite good results. Look up
"Eulerian Stress" and you will have the formulas you need.

The smart way to get cheap CAD and FEA software is to enroll in you local
community college. For about $100 tuition, you become a "student"
and qualify for the educational versions of very high-end software.

Bill Dube.

Thanks Bill See the previous message for the properties of 4340.
But here are some better data.

  Density (lb / cu. in.)         0.28
Specific Gravity     7.8
Specific Heat (Btu/lb/Deg F - [32-212 Deg F])     0.116
Melting Point (Deg F)     2600
Thermal Conductivity     21
Mean Coeff Thermal Expansion     6.6
Modulus of Elasticity Tension     33 [million]

I was perhaps a little low on the yield. More like 100,000 psi.

Yes I was thinking of taking a class on tig welding :) I have a tig and I
got a new LCD helmet for Christmas from my son. That is how I got my Rhino.

I am homing in on a cheap 120,000 RPM turbo compound gear box. Mostly off
the shelf parts.

Paul Lamar ...No rotor no motor.

The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net Copyright 1998-2005 All world
wide rights reserved.



Paul,

I loaded 4340 from my standard library.  This is 4340 normalized and not
hardened all the way to it's max hardness.

The red areas are questionable only in that I assumed a "nip" between the
plant gears and the ring gear as 1mm.  If I used an infinitely sharp nip
you'd slice right through the material no mater how strong it is and that's
not realistic.

I don't have a lot of time on this (15min) so there is no tuning.

I did discover that if you do a study without an external constraint of some
kind the part zips off into space because the software iterates through the
nodes and even the least amount of force difference 10^-13 in this case
causes the ring gear to drive out of sight.  Interesting to watch!

So, I put a constraint opposite one of the contact points to keep the ring
gear from flying off.

-Ben

Thanks Ben! Wonderful!!!! We are on the verge of a major breakthrough
in fuel consumption of the turbo compound rotary amounting to 15% to
20% better. One false start with the Rotrex gear box
I am afraid.

Paul Lamar ...No rotor no motor.

The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2005 All world wide rights reserved.