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Subject: Re: Looking for comments on SMRTSIZE and free meshing in general
Author: John Crawford
Date: 2001-01-30 12:01:00

I guess each person has his/her own way of working. Some people/companies
embrace new ways of doing things and others don't. I use any meshing scheme
that works quickly and gives the answers I'm looking for. I frequently use
free tet meshing for complex geometries and then tie them to mapped meshes
using pyramid elements. This works well for me. I'll try to use tet
elements where I think I'll need to refine the mesh, and bricks where I
won't. Tets are easy to refine, bricks are more troublesome. I don't tend
to use smartsizing very much, although I use it on occasion. I've had mixed
results using it, and have fallen back on using my own best estimate for
initial mesh sizing.

Looking towards the future a bit, it seems to me that as time progresses we
will become less and less daunted by large models and more interested in
understanding the quality of our answers, which means we will perform mesh
refinement more frequently. Tet meshes lend themselves towards easy local
refinement, whereas mapped meshes tend not to. So I think the future of FEA
will lean towards free meshing with tet elements with local refinement and
maybe increasing element order. If this is true, then embracing free
meshing with tets would seem to be a reasonable thing to do. Better sooner
than later.

It all comes down to time vs. accuracy. Time is the enemy while accuracy is
the measurement of how useful our answer is. The idea is to minimize time
and maximize accuracy. Easier said than done, but mapped meshing frequently
requires subdivision of geometry into map-meshable (is that at word?) hunks,
and this takes time. Additional time is spent refining the mapped mesh if
we aren't happy with our results. Free meshing has the edge in both of
these areas, but the resulting large model sizes that accompany tet meshes
present difficulties that at the present time seem to be best addressed by
using your judgement and experience to efficiently use free and mapped
meshing techniques together.

This is why we make the big bucks.

John Crawford
Honeywell Engines
Phoenix, AZ
john.crawford@h...

-----Original Message-----
[mailto:JPatterson@h...]
Sent: Tuesday, January 30, 2001 7:13 AM
To: xansys

general

Hello All,

I'm looking for comments, insights, and experiences regarding the use of
Smart Sizing and free mesh models. Recently, through attrition and
layoffs, our analysis department has been reduced to a single user--me!
Due to this circumstance, as well as a still unrelenting work flow, I'm
looking for ways to get models out faster, but still with quality results.
I've been taught to use mapped meshing as much as possible, especially by
my recently departed manager. Since he's left, I've come to learn that the
number one complaint about our department was that "it takes 2 years to get
any results". Now I have the opportunity to experiment with some methods
that I hope could allow models to be meshed faster.

I guess my concern is based on my distrust of anything that says it works
"automatically". It looks very attractive to just set up my areas, type
SMRTSIZE,6, and then go get a coke. It also seems like every time I see
any sales propaganda, it's a free mesh. Is this just sales hype? Are
users applying this successfully? What are your thought about mapped vs.
free meshing? I'm in the process of some experiments using both methods,
but thought I would tap this group for some worldly advice. Almost all my
models are shell elements of welded assemblies.

Thanks,

Jim P.

James J. Patterson
Engineering Analyst
Hendrickson Trailer Suspension Systems
2070 Industrial Place SE
Canton, OH 44707
Tele: 330-489-0095
Fax: 330-489-0450
email: jpatterson@h...

Posts possibly associated with message #20625AuthorDateScore
20612Looking for comments on SMRTSIZE and free meshing in generalJim Patterson2001/01/30 
20617Re: Looking for comments on SMRTSIZE and free meshing in generalDave Lindeman2001/01/30 
20624Re: Looking for comments on SMRTSIZE and free meshing in generalPaul DiCristoforo2001/01/30 
20625Re: Looking for comments on SMRTSIZE and free meshing in generalJohn Crawford2001/01/30 
20676Re: Looking for comments on SMRTSIZE and free meshing in generalVincent Raillard2001/01/31