Stress Analysis

If someone was to design a steel tube fuselage or a modification to a
steel tube fuselage, does anybody know of a relatively inexpensive and
painless way to get a stress analysis done, or software to do it?

John

On Jan 14, 9:31 am, "J.Kahn" wrote:
does anybody know of a relatively inexpensive and
painless way to get a stress analysis done,

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'Stress Analysis Made Painless' by Raoul J. Hoffman.

Mr. Hoffman was an aeronautical engineer who crunched the numbers for
Matty Laird. His series of illustrated articles on stress analysis
appeared in flying magazines during the 1930's. They began with
'Properties of Airplane Materials' and included 'Elementary Graphical
Diagrams,' 'Graphical Resolution of Forces and Loads' and more than a
dozen other extremely valuable articles written for the novice
engineer.

Back when the EAA cared about more than air shows the Hoffman articles
were compiled in a single manual 'Engineering for the Amateur Aircraft
Builder' and offered to members for two dollars.

There are also a number of texts intended for the first-year
engineering student such as 'Fundamentals of Aircraft Structural
Analysis' by Frederick K. Teichmann.

During the 1930's most high schools in America offered courses dealing
with aviation. These were supported by a number of texts that usually
included stress analysis at the practical level, showing not only how
to do the various calculations but how to set-up practical experiments
for testing ribs, beams, struts and so forth.

Aviation trade-schools run by Boeing (Oakland), Northrup, Spartan and
others often published their own manuals, all of which touched upon
stress analysis although their main emphasis was on maintenance &
repair, rather than design.

This material is still out there although it's getting harder to
find. The physics & math hasn't changed -- the equations remain the
same -- and are just as applicable to today's home-builders as they
were to the yesterday's aircraft manufacturers. This subject also
provides a neat lesson in America's decline, in that you can see the
same basic-level material once offered in our public high-schools now
treated as a college-level subject for which the student is required
to pay tens of thousands of dollars.

-R.S.Hoover
-EAA 58400 (Life Member)

On Jan 14, 11:31*am, "J.Kahn" wrote:
If someone was to design a steel tube fuselage or a modification to a
steel tube fuselage, does anybody know of a relatively inexpensive and
painless way to get a stress analysis done, or software to do it?

John

There is a free finite element program available for download from
this NASA website. They may ask for voluntary donations.

http://femci.gsfc.nasa.gov/links.html

The link on the page that I am talking about is the MYSTRAN link near
the bottom of the page. It is a finite element analysis program
written by Dr. Bill Case of NASA.
There are many other links that should be useful.

Regards,
Bud

On Jan 14, 11:31*am, "J.Kahn" wrote:
If someone was to design a steel tube fuselage or a modification to a
steel tube fuselage, does anybody know of a relatively inexpensive and
painless way to get a stress analysis done, or software to do it?

John

Sorry, I got two links mixed up. This link

http://homepage.usask.ca/~ijm451/fin...resources.html

has references that are free or donation asked. The MYSTRAN software
is $200 for a 1 year license. Cheap in the software world.

Regards,
Bud

wrote:
On Jan 14, 11:31 am, "J.Kahn" wrote:
If someone was to design a steel tube fuselage or a modification to a
steel tube fuselage, does anybody know of a relatively inexpensive and
painless way to get a stress analysis done, or software to do it?

John

Sorry, I got two links mixed up. This link

http://homepage.usask.ca/~ijm451/fin...resources.html

has references that are free or donation asked. The MYSTRAN software
is $200 for a 1 year license. Cheap in the software world.

Regards,
Bud

A Finite Element Analysis package is worse than useless without mastery
of the basics. If you can't do it by hand, what you get from FEA could
get you or someone else killed. EAA still sells "Stress Without Tears"
that takes you through the basic principles and simplified equations for
doing stress analysis of aircraft structures. If you can't master that,
you aren't going to do much better learning the ins and outs of meshing
for FEA.

Charles.

On Jan 14, 10:11*pm, Charles Vincent wrote:
wrote:
On Jan 14, 11:31 am, "J.Kahn" wrote:
If someone was to design a steel tube fuselage or a modification to a
steel tube fuselage, does anybody know of a relatively inexpensive and
painless way to get a stress analysis done, or software to do it?

John

Sorry, I got two links mixed up. This link

http://homepage.usask.ca/~ijm451/fin...resources.html

has references that are free or donation asked. The MYSTRAN software
is $200 for a 1 year license. Cheap in the software world.

Regards,
Bud

A Finite Element Analysis package is worse than useless without mastery
of the basics. *If you can't do it by hand, what you get from FEA could
get you or someone else killed. *EAA still sells "Stress Without Tears"
that takes you through the basic principles and simplified equations for
doing stress analysis of aircraft structures. *If you can't master that,
you aren't going to do much better learning the ins and outs of meshing
for FEA.

Charles.- Hide quoted text -

- Show quoted text -

'Stress Analysis Made Painless' by Raoul J. Hoffman

Hand analysis can be made painless through simplified equations
available from somebody, whereas setting up a finite analysis input
file in order to let a computer do the calcs is beyond his grasp. GOT
IT! thanks.

Bud

On Jan 14, 11:31*am, "J.Kahn" wrote:
If someone was to design a steel tube fuselage or a modification to a
steel tube fuselage,

John

Now that the beers have worn off.....

does anybody know of a relatively inexpensive and
painless way to get a stress analysis done

No!

Bud

wrote:
On Jan 14, 10:11 pm, Charles Vincent wrote:
A Finite Element Analysis package is worse than useless without mastery
of the basics. If you can't do it by hand, what you get from FEA could
get you or someone else killed. EAA still sells "Stress Without Tears"
that takes you through the basic principles and simplified equations for
doing stress analysis of aircraft structures. If you can't master that,
you aren't going to do much better learning the ins and outs of meshing
for FEA.

Charles.- Hide quoted text -

- Show quoted text -

'Stress Analysis Made Painless' by Raoul J. Hoffman

Hand analysis can be made painless through simplified equations
available from somebody, whereas setting up a finite analysis input
file in order to let a computer do the calcs is beyond his grasp. GOT
IT! thanks.

Bud

Without a basic grounding in airframe stress analysis, how does one know
where to apply the loads and the vectors? How does one determine the
magnitude of the loads? Setting aside the learning curve for FEA and
the program, how does one know the solution is in the realm of possible
if you haven't applied any hand calcs beforehand? A comparison to a
second independent analysis method is generally part of the FEA process.

Finally, FEA is not simple. ISO guidelines suggest a minimum of five
years engineering experience and six months of post training FEA
experience for FEA work on critical structures. FEA texts will assume
you already understand stress analysis. The sources suggested by others
here for hand calcs of stress(other than Teichmann) do not In the
end, unless you are set on generating worthless pretty color pictures,
you will have to hit the hand calcs anyway.

Charles

Charles

On Jan 14, 11:31*am, "J.Kahn" wrote:
If someone was to design a steel tube fuselage or a modification to a
steel tube fuselage, does anybody know of a relatively inexpensive and
painless way to get a stress analysis done, or software to do it?

John

Consider posting this question to www.eng-tips.com

Charles Vincent wrote:
wrote:
On Jan 14, 11:31 am, "J.Kahn" wrote:
If someone was to design a steel tube fuselage or a modification to a
steel tube fuselage, does anybody know of a relatively inexpensive and
painless way to get a stress analysis done, or software to do it?

John

Sorry, I got two links mixed up. This link

http://homepage.usask.ca/~ijm451/fin...resources.html

has references that are free or donation asked. The MYSTRAN software
is $200 for a 1 year license. Cheap in the software world.

Regards,
Bud

A Finite Element Analysis package is worse than useless without mastery
of the basics. If you can't do it by hand, what you get from FEA could
get you or someone else killed. EAA still sells "Stress Without Tears"
that takes you through the basic principles and simplified equations for
doing stress analysis of aircraft structures. If you can't master that,
you aren't going to do much better learning the ins and outs of meshing
for FEA.

Charles.

Don't see it on the EAA site but it is available on Amazon. Just what
I'm looking for.

Thanks for the input all!

John