femfat

Winter Edition 2007 - No. 13
Although the editor's meeting wanted to greet
you with a ghostly halloween pumpkin - this
is, after all, the 13th issue of the Newsletter
- we would like to use this contemplative
season of advent to pause and think instead,
especially now that we can distribute the
brand new Version 4.7, well conceived and
tested - which fills us with particular pride.
In this context we would like to immediately
lead over to a retrospective of an
Excellent 2007 for FEMFAT
We are delighted with FEMFAT's success
around the globe, which was crowned by
the Technical Innovation Prize of the State
of Lower Austria, presented to Dr. Christian
Gaier, Head of FEMFAT Development, on
October 23, 2007 in St. Pölten.
The technically high-quality presentations
at the FEMFAT User Meeting, together with
the FEMFAT 4.7 preview, ensured that the
orders for FEMFAT came streaming in, even
during the "summer break". We are ver y
pleased with this development.
Karl Ritter von Gega Prize 2007, presented by
Ernest Gabmann (Lower Austria State Economic
Council) and Sonja Zwazl (WKNO President) to
Dr. Christian Gaier (Head of FEMFAT Development) and Dipl.-Ing. Helmut Antensteiner (Head
of Project Controlling) for innovative analysis
concepts in FEMFAT
Contents:
FEMFAT Retrospective _________ 1
Evaluation of short-fiber-reinforced
plastics with FEMFAT MAX 4.7 ____ 2
FAQs:
•How can FEMFAT process my _
ABAQUS odb files? __________ 3
•How should load case numbers
be defined in TransMAX? _____ 3
• How impor tant is the time in- _
formation in HEAT Sehitoglu? _ 3
Training/Events _______________
Tips _________________________
Event Calendar ________________
Publisher's Information ________
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Visit our website:
www.femfat.com
Despite extensive development work - which
manifests itself primarily in a reduction in
computation times, and more user-friendly
operation and visualization - and an increase
in payroll costs, FEMFAT module prices have
not increased in the last five years. This
has only been possible thanks to increased
deployment of FEMFAT. It is also remarkable
that FEMFAT was able to increase its standing outside of the dominating vehicle industry. The possible fields of application for
FEMFAT are by no means exhausted and we
are already working on fur ther methods,
which we will make available to you in the
coming years, tailor-made and verified.
Today we thank you for your trust in FEMFAT
and our team and wish you a Merry Christmas and a Happy New Year.
your FEMFAT-Team
Japan TEC Show
The DMSK 2007 was held from October
1 to 3 in the INTEX (Int. Exhibition Center)
in Osaka (30,000 delegates). Our young
and dynamic team from the MAGNA Tokyo
Of fice (Noriyuki Muramatsu, Kazumasu
Kato and Terue Goto) organized par ticipation in this technical exhibition for the
second time in order to introduce our
software products to the interested Japanese public. Numerous manufacturer's of
machine tools and household products
also showed an interest in FEMFAT. Great
interest was also noted in the new analysis
options available for plastics. During this
3 day event approximately 80 consultations
were held, representing an important step
for Japanese industry. To me, the Japanese
are highly interested in, and open to,
anything new, in contrast to many central
Europeans. An exhibition booth at the
DMSK 2008 is already booked; before
this we are also represented at the JSAE
in May 2008.
Dear Tokyo team – keep up the good work –
and many thanks for your hard work.
Helmut Dannbauer
FEMFATNEWSLETTER
Winter Edition 2007 - No. 13
Evaluation of short-fiber-reinforced plastics with FEMFAT MAX 4.7
In FEMFAT MAX (BASIC is on its way) it is now possible to evaluate
components made of short-fiber-reinforced plastics, taking the fiber
orientation and fiber distribution into special consideration (FEMFAT
"POLY"). Injection molding simulation results can be processed from
MOLDFLOW directly within FEMFAT for this purpose (Fig. 1).
MOLDFLOW
injection
die cast
simulation
Abaqus
interface
for
MOLDFLOW
Abaqus
stress
analysis
These material parameters can be taken from tests on unnotched
flat samples, carried out on injection molded slabs parallel and
perpendicular to the fiber orientation (Fig. 3). If not all data for the
transverse fiber direction are available, FEMFAT partially utilizes the
data from the parallel samples.
FEMFAT
fatigue life
prediction
Fig. 1: Data flow from the injection molding simulation through the
entity stress analysis to the damage forecast.
The injection molding simulation file job-name-fiber-tensor.xm1 contains
the fiber orientation tensor for every solid element (generally a linear
tetrahedron), from which the three principal orthotropy directions
and the fiber components λi for each principal direction can be
computed (Fig. 2). In the next step, this information is transferred
("mapped") from the FEM mesh of the injection molding simulation
to the FEM mesh of the strength analysis .
Fig. 4 Material data perpendicular to fiber
Fig. 2: left: Example of random fiber distribution;
right: Example of highly pronounced fiber orientation;
Since the middle of this year MOLDFLOW has made available a
software application to transfer data to ABAQUS. In FEMFAT, an
orientation tensor is applied to nodes, which is determined by
averaging the tensors at the neighboring elements for each component.
In addition, static and cyclic material parameters for tensile and
compressive loads parallel and perpendicular to the fiber orientation
are required for a damage prediction using FEMFAT (Fig. 4).
Fig. 5: "Fiber orientation" influence
If no cyclic material parameters are available (S/N curve, cyclic
stress-strain curves), it may be possible to roughly estimate them
from static parameters (tensile strength). The FEMFAT team will be
happy to assist.
With regard to the theoretical aspects, it should be noted that it was
necessary to expand the critical cutting plane method. Due to the
orthotropic strength distribution, failure can also occur in a plane
subject to minor loading, in contrast to isotropic materials.
For practical application please watch out that the check box for the
new "Fiber orientation" influence must be activated (Fig. 5). Nothing
now stands in the way of an analysis using "FEMFAT POLY", because
no separate module with a corresponding license is required.
Fig. 3: Sampling from injection molded slabs.
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Christian Gaier
FEMFATNEWSLETTER
Winter Edition 2007 - No. 13
FAQs
How can FEMFAT process my ABAQUS odb files?
You may remember from older Newsletters that the so-called odb
libraries, which functions as a translator between the two software
products, are required to import ABAQUS odb files into FEMFAT.
The definition also applies to ChannelMAX, in analogy to TransMAX.
In addition, the user must note that intermediate increments can be
defined using load case numbers in the ABAQUS (.fil and .odb)
interface. In this case the default setting must be deactivated (see
Fig. 2).
The current odb libraries (6.7.x) are automatically installed when
installing the new FEMFAT 4.7 Version. That is, the user must now
keep this up-to-date, because it is possible for the libraries to be
modified in the course of an existing version of FEMFAT. This depends
entirely on the new ABAQUS versions released in the interim.
These libraries are available as compressed files for a variety of
hardware platforms on our homepage at www.femfat.com (registration
necessary).
It is possible to download "odb6.6.x" separately in the final column,
as shown in Fig. 1. It should be noted that these libraries are only
downwards compatible. For example, this means that odb files created
using ABAQUS 6.6.x can also be imported into FEMFAT with the aid
of 6.7.x odb libraries.
Fig.2
As of FEMFAT Version 4.7 it is also possible to have the result file
scanned (right mouse button in the "Stress data" input box); the
user then has a comfortable option for selecting via the existing load
cases.
Eberhard Dutzler
How important is the time information in HEAT Sehitoglu?
Analysis of damage or fatigue life from load-time series' (LTS) was
previously performed in FEMFAT MAX regardless of the elapsed time.
Strains were not utilized in either ChannelMAX or TransMAX due to the
approach via local stresses and the influence parameter concept. This
changed with the implementation of the damage hypothesis according
to Prof. Huseyin Sehitoglu in TransMAX. Sehitoglu divides the total
damage for thermomechanical fatigue into 3 terms:
Dmech … the mechanical damage component according to
COFFIN/MANSON
Dox …… the oxidation damage/ambient damage
component
Dcreep … the creep damage component
Dtotal = Dmech + Dox + Dcreep
Fig. 1: Download area at www.femfat.com
It is recommended to always install the odb libraries corresponding
to the ABAQUS versions to be employed, otherwise the odb files are
"upgraded" and increase in size. Speaking of installation – the
uncompressed odb libraries belong in the FEMFAT installation folder,
more precisely in the odb folder created there automatically during
installation.
(Example:....\femfat47\platforms\winnt_51_i686_32bit\odb\).
Marco Fahrner
In the oxidation damage according to BOISMIER, KADIOGLU and
ox
.
SEHITOGLU the oxidation phase Φ and the strain rate (ε) are very
highly dependent on the strain history over time.
Creep damage is most prominent for an in-phase TMF load (mechanical
loads enhance thermal strain) and is integrated over the cycle time.
This naturally implies that damage is time-dependent.
How should load case numbers be defined in TransMAX?
This is different depending on the file format:
File Format
I-deas (.unv)
Nastran Punch (.pch)
Ansys Presol (.lis)
Patran Result (.rpt)
Medina (.bof)
Pro/Mechanica (.*s*)
Nastran (.op2)
Abaqus (.odb)
Cosmos/M (.out)
Abaqus (.fil)
Ansys (.rst)
LSDyna (.d3plot)
Marc (.t16)
Permas (.post)
Load case number definition
Specify load case number
Specify load case number
Only one load case possible in result file
Only one load case possible in result file
Load cases always begin with 1
Only one load case possible in result file
Load cases always begin with 1
Load cases always begin with 1
Only one load case possible in result file
Load cases always begin with 1
Load cases always begin with 1
Load cases always begin with 1
Load cases always begin with 1
Load cases always begin with 1
The time information (unit: seconds) can be defined in a number of
ways. Either the step time from the stress, strain or temperature
results can be used (which makes more uncommon step time
definitions necessary) or a separate table is imported as a text file.
This can be performed on the "Time information" tab.
Up until Version 4.6 the time integration for oxidation and creep
damage was carried out relatively simply. Different resolutions when
specifiying a heating process across various states led to different
results. Time integration has been greatly improved as of Version
4.7. It is now sufficient to specify start and end times, the temperature
history for this period is then implied as linear. This leads to a precise
result despite only a small amount of data being necessary and a
fast analysis.
Axel Werkhausen
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FEMFATNEWSLETTER
Winter Edition 2007 - No. 13
Training - Dates 2008
Fatigue life/Damage and
safety factors for simple loads,
comprehensive FE-interfaces
and material database
Engineering Center Steyr, St. Valentin
6.-7. February
16.-17. April
3.-4. June
6.-7. August
15.-16. October
3.-4. December
Engineering Center Troy, Detroit
29. February
18. June
11. September
Prices (excl. VAT):
per delegate
for each further delegate
from the same company
University/Research group
Euro 770.00
Euro 610.00
Euro 300.00
Including 2 month FEMFAT evaluation license
Information: a.schmidthaler@ecs.steyr.com
3D-postprocessor and
WELD definition
Multiaxial fatigue
Welded structures
*** TIPS *** TIPS *** TIPS *** TIPS *** TIPS *** TIPS *** TIPS *** TIPS ***
Spot-joined structures
FEMFAT VISUALIZER price increase
As previously announced in Newsletter 10, we have decided to increase the price of the VISUALIZER for
2008. The module has been greatly expanded in the past (e.g. weld definitions) and this is the first increase
for several years.
Fast movers can still buy VISUALIZER at its original price until the end of 2007. A 20% increase will take
effect as of January 1, 2008.
Thermo-mechanical fatigue
Always use a current version of FEMFAT!
PLAST
We recommend always to use the FEMFAT versions currently made available on our homepage www.femfat.com.
Of course it is not always easy to keep up with the latest software releases, especially in large companies
due to the longer IT order channels, but it is enormously important.
Bugs, which creep into every software product whether we like it or not, are eliminated in maintenance
versions and interfaces brought up-to-date.
For new "Major Releases" such as the current version 4.7 you can profit from module extensions, new
methods and improved user interfaces. We realize that moving to a new version involves a certain amount
of work; however, the advantages far outweigh this disadvantage. A compact description of all improvements
is available in the release notes on the homepage www.femfat.com.
Axel Werkhausen
Local plasticity
BREAK
Static safety factors
STRAIN
Virtual strain gage/
Measured strain damage
FEDIS
Sub-modeling
Event Calendar
Engine dynamics/Acoustics
simulation
Analysis & preparation of data
Impressum:
Engineering Center Steyr GmbH & Co KG
Steyrer Strasse 32, A-4300 St. Valentin
Tel: +43 7435 501 303,
Fax: +43 7435 501 300
a.schmidthaler@ecs.steyr.com
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SAE India
Marcus Evans Conference: “IT-supported PDP”
FEMFAT Road Show
8. Stuttgarter Symposium
Assurance of System Reliability, DVM Workgroup
SAE World Congress 2008
2nd Fatigue Symposium
DVM Conference 2008
FEMFAT Road Show
HdT Seminar “Material Models for Finite Elements”
Commercial Vehicle Workshop Graz
SF2M Conference “Fatigue and Plasticity”
SCT 2008
Symposium on Structural Durability/LBF
FEMFAT Japanese User Meeting
New Delhi
Stuttgart
Munich
Stuttgart
Koblenz
Detroit
Leoben
Berlin
Zurich
Munich
Graz
Paris
Wiesbaden
Darmstadt
Nagoya
09.-11.01.2008
30.-31.01.2008
06.03.2008
11.-12.03.2008
02.-03.04.2008
14.-18.04.2008
23-.24.04.2008
23.-25.04.2008
29.04.2008
06.-07.05.2008
16.05.2008
20.-22.05.2008
01.-05.06.2008
05.-06.06.2008
20.06.2008