Do you have a favorite software package for finite element analysis?

I need to look into different FEA packages for my company. Our primary interest would be seismic analysis of our filtration systems. We do air filtration systems for nuclear, biological, and industrial applications and have quite a few government contracts.

So, basically, no moving parts, and fairly simple structural analysis, but as I said, we need to do seismic analysis.

3/14/2007 4:51:47 PM

only one i've ever used is ansys when i took finite... it seemed decently easy to work with.

3/14/2007 5:44:57 PM

From the mind of Dr. James Pearson...

Ansys will be suitable for your companies needs. Ansys is not the
cheapest software to license however; if you are an NCSU student you
can own a legitimate copy through EOS, for free, which will only run
with a NCSU login and an internet connection capable of finding the
NCSU license server (this has the potential of saving the company
money, I am positive a company license for 1 year for ANSYS ver 9.0 is
well over $20k). Sometimes, in my experience Ansys has not had the
most satisfactory import abilities from CAD packages, so you may need
to check on what software you currently use to model the filters. I
am sure if you guys paid for a company license, customer service would
be great.

When you say seismic, here is what I see you guys doing: In
aerospace applications for crash/shock (aka seismic) loading, the
normal/easiest way companies proof parts is by 1st) Running a
simulation using the part (filters) and 'normal expected use loads',
then, 2) taking the 'normal expected use loads' on the part
(filters) and just multiplying these by ~20, then run the simulation
again.

This is easily and efficiently done in Ansys (as well as almost any
other FEA software, like Cosmo, Nike3d, Comsol (high power, easy to
use, cheap, all around good [for instance, if you want to run a
coupled field model, where you have actual water in a solid filter
subjected to a crash loading, this would be the easiest way to go -
def. not ansys in this case*]), a TON of free codes from the DOE and
Sandia).

* It is easy to include water in the model as a solid with some
weight/density (perhaps doubled, to account for the approximation of
water as a solid)

This is a 'static' analysis. The only hard or tricky part in these
analysis', to obtain reasonable results, is the application of the
'boundary conditions'.

True seismic loadings are dynamic and random vibe. Ansys can do
these analysis'. They have many more details to handle and the
results are harder to interpret. ESPECIALLY if you are running models
in 3D. However, I highly doubt you people are trying to run dynamic
(w/ wave effects) simulations on these systems. It is easy, in Ansys,
to run a series of consecutive linked static loadings where over time
you change the loadings to match some design requirement. These are
quasi-static runs.

When you seismic, you may mean vibrational modes and mode shapes.
Everything (software) will give you this - it is much more laborious
in 3d. This is a standard component of any true seismic analysis.
However the information supplied is not necessarily linked to failure,
and most be analyzed first and then used second to generate loadings
for a seperate model using the static technique.

Big issues at the end of the day:

1) What is you current CAD software and will it import
2) Are the models in 2D or 3D
3) Will you run static, quasi-static or true dynamic models
4) Are you modelling fluids and solid structure together, ie FSI
(fluid surface interaciton) - if so no Ansys!
5) Almost everything will give you the vibrational modes and mode
shapes for a solid structure

ANSYS will work well for solid models (no fluid), 2D (and 3D but other
programs are better), static + quasi-static + dynamic (avoid in
general, except for vibrational mode analysis).

3/15/2007 9:03:29 AM

Ah. Lots of help. Wonderful.

3/15/2007 8:31:53 PM