Customer
Case Study
their solution...
 Noise and vibration control through innovation -
For more than 15 years,
Damping Technologies Inc. (DTI) has been solving noise
and vibration problems, primarily for makers of
automobiles and aircraft but its products can also be
found in yachts, skis and computer hard drives. DTI’s
advantage is a comprehensive understanding of the
dynamic properties of materials including metals, elastomers, plastics, polymers, glass enamels and
composites. Using this knowledge, engineers and
scientists create application-specific solutions that in
most cases are lightweight, add-on countermeasures, such
that the design of the customer’s part does not need to
be changed. Because the goal of DTI’s products is
to suppress noise, vibrations and/or high cycle fatigue
damage due to resonance response, much of the company’s R&D work involves dynamic
finite element analysis (FEA). These analyses can take a
long time to solve. “The type of analysis we do requires
a lot of iteration and a lot of resolution in the model
in terms of degrees of freedom,” explains Kristopher Notestine, manager of R&D at DTI. “A typical analysis on
a very small structure can take four to eight days to
run.” With the goal of speeding these analyses,
DTI decided to upgrade its hardware to an HP ProLiant
system running Linux and equipped with eight CPUs and 16
gigabytes of memory. The upgrade provided the
opportunity to reconsider the analysis software as well,
which was Ansys at the time. “We wanted something that
would run well on our new hardware, so we looked at
Ansys, both Nastrans (the NX Nastran solution from
Siemens PLM Software and MSC Nastran) and Abaqus,” says
Notestine.
Support is important
-
Following a thorough evaluation process, the company
chose NX Nastran for several reasons. Not only did it
bring a decided speed advantage, being nearly twice as
fast as Ansys during benchmarking. “NX Nastran was
faster but it also came with the best support,”
Notestine notes. The local distributor is netPLM in
Indianapolis. “There are very good reps from netPLM,
both technically and in terms of sales, and there was
good teamwork between them and the people from Siemens,”
Notestine says. “That gave us confidence in the support
we would receive, and since then that has turned out to
be the case. The follow-up support has been more
regular than what we got from Ansys.Another deciding factor for NX
Nastran was the fact that many of DTI’s customers work with Nastran.
“Customers in the defense, satellite and commercial aerospace
industries – they’re all using Nastran and they provide data to us
in Nastran format,” Notestine adds. “When we were using Ansys, we
had to convert their models to Ansys format and then make sure those
models were accurate. That took from 30 to 60 days, which really put
us behind. Now that we have NX Nastran, we won’t have issues with
data conversion.”
More than twice as fast -
Although the speed advantage with NX Nastran was
 evident during the evaluation process, it
has actually turned out to be even better than it appeared at that time. During the evaluation process,
the representatives of the various software benchmarked
a simple model with direct frequency response and also
ran one of DTI’s typical models containing visco-elastic
material where the properties were frequency dependent.
The test run with Ansys took an hour and half to solve.
The same problem with NX Nastran took about 48 minutes.
(The accuracy of the NX Nastran solution was verified
with DTI’s test data.) According to Notestine, now that
the NX Nastran is in use, it is taking about 25 percent
as long as Ansys, citing one analysis that previously
took 55 minutes and now takes only 12 to 14 minutes with
NX Nastran. In making the transition to NX Nastran,
DTI also implemented a new pre and post-processor, the
Femap solution from Siemens, on netPLM’s recommendation.
“I was used to ANSYS [which also provided pre and post
processing],” says Notestine. “But as I worked through
the Femap tutorials, I found that it was intuitive and
that I could get up and running with it quickly. It’s
flexible and intuitive.” For a company whose
slogan is “noise and vibration control through material
innovation,” an efficient R&D process is critical. It is
key to creating new damping technology, such as DTI’s
Stand- Off damping systems that deliver extremely high
levels of structural damping with minimum weight
addition. With NX Nastran and Femap, DTI has the FEA
solution it needs to continue to provide unique damping
solutions.
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Indianapolis
Office: 317-222-1480