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Subject: Re: Poll results for xansys - optimization
Author: Frank Exius
Date: 2001-02-24 11:32:00

trial and error is my life, appart from small system approach
and next cubicle.......

the trouble with knowledge-based systems is, you need to 'extract' knowledge
from knowlegeable people. Since appart from smart talk, the knowledgables
might find them self 'not fully' retributed for giving advice -instead the
'oiled'
guys take the benefit - they might conclude that it's not worth it.
(Sorry about bitter chocolate - stop tears)

Appart from this, the idea of building a system which is up to date
and has accumulated past knowledge (biggest bit) in it along
with new - manufacturing techniques, design consideration, assembly
and revision hints all with cost reference .... sure sounds great.

Such product should focuse on well defined domains as particular
product, manufacturing cathegorie or similar criteria, at least for a start.
I did see a posting wrt of a well tailored engagement in the archive,
was for GE a 'plastics selector' application by John Crawford.

I think such is good stuff. There has to be qualified people behind it,
dedicated managment which understands the marketing benefits BY
understanding the engineering benefits of a - well thought out - ITproduct.

If you aim at profits, you have financial committment - that's what
management is paid for, access and handle risk issues.

Cheers,
Frank Exius IFE
BONN Germany - Rome ITALY

----- Original Message -----
To:
Sent: Friday, February 23, 2001 7:23 PM

> Chris has nailed this issue pretty well. Optimization needs to involve
many
> factors, not just design features. If Ansys could incorporate
standardized
> tooling, sheet metal gages, bolt hole clearances, material spec minimums,
> casting practices, and manufacturing tolerance into the optimization
> process, then it would be much more practical. But then again, part of
the
> learning and fun in this profession comes from trial and error ....

> Mark C. Tate
> Principal Analysis Engineer
> Hamilton Sundstrand - A United Technologies Company
> mark.tate@h...

> -----Original Message-----
> From: Christopher Wright [mailto:chrisw@s...]
> Sent: Friday, February 23, 2001 9:30 AM
> To: XANSYS
> Subject: Re: [xansys] Poll results for xansys - optimization

> >I think that I can overcopme the "fiddle factor" with optimization
> >if I see that the payoff is there.
> I may as well chip in here. There's really not much general value in
> optimization because it's restricted to a very narrow area. Problems like
> 'optimal' fillet radii are trivial and not worth learning the necessary
> vocabulary, let alone waiting around for results. Real engineering optima
> involve matters such as cost, schedule and producibility. Weight savings
> is sueful, but only if it comes with a cost or time savings. I once
> worked on a rib-stiffened cylindrical shell where the 'optimized'
> structure really saved a lot of weight by adding a great many small,
> closely spaced stiffeners. But the fabrication costs were monstrous--it
> wasn't an optimum anything.

> Engineering designs often require specific types of components--you're
> stuck with the off-optimum just because plate and fasteners and rolled
> shapes in any old size you want.

> The biggest problem (apart form inability to import parameterized CAD
> geometry) is that by the time you have enough information to 'optimize' a
> design, it's already pretty much cast in concrete, particularly if you're
> waiting on a CAD model. A good example is a pressure vessel with a flat
> head--you can figure out the 'optimum' combination of head and shell
> thickness for the least material, but FEA won't explain that a flat head
> is a rotten idea from the outset.

> OTOH, I daresay situations involving proof of concept lend themselves to
> both parameterization and optimization but the use of small models for
> studying physics seems to have gone out of fashion.

> Christopher Wright P.E. |"They couldn't hit an elephant from
> chrisw@s... | this distance" (last words of Gen.
> ___________________________| John Sedgwick, Spotsylvania 1864)
> http://www.skypoint.com/~chrisw

Posts possibly associated with message #21342AuthorDateScore
21301Poll results for xansys - optimizationDan Bohlen2001/02/23 
21303Re: Poll results for xansys - optimizationDanny Levine2001/02/23 
21311Re: Poll results for xansys - optimizationParis Altidis2001/02/23 
21321Re: Poll results for xansys - optimizationChristopher Wright1991/02/23 
21323Re: Poll results for xansys - optimizationMark Tate2001/02/23 
21325Re: Poll results for xansys - optimizationParis Altidis2001/02/23 
21334Re: Poll results for xansys - optimizationChristopher Wright1991/02/23 
21342Re: Poll results for xansys - optimizationFrank Exius2001/02/24 
21360Re: Poll results for xansys - optimizationShen-Yeh Chen2001/02/26 
21371Re: Poll results for xansys - optimizationParis Altidis2001/02/26 
25378Re: Poll results for xansys - optimizationChris Rogers2001/06/28