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First commercial Software Solution for Finite
Element Analysis of the Roll Forming Process
Roll forming has been known as a high productive
method for the production of profiles or longitudinal welded tubes and
pipes. However, in order to be able to use the full efficiency of the
roll forming process quality management has to start already in the
design department. New methods and software technologies can assist the
tooling engineer to improve the design quality and thus the quality of
the final product.
The virtual Roll Forming Line
"Having released our newest COPRA software
module, COPRA FEA Roll Forming, we have taken a decicive step towards a
virtual roll forming mill" Stefan Freitag (technical director and
president of data M Software GmbH) proudly states.
‘COPRA FEA Roll Forming’ extends the existing
software solution COPRA DTM (Deformation technology Module) by some
substantial features. The non-linear solver included in COPRA FEA Roll
Forming particularly allows to take into account forces and friction
conditions. Also critical roll forming geometries can be looked at more
accurately than ever.
COPRA FEA Roll Forming is not going to substitute data M´s worl wide
leading simulation- and analysis-software COPRA DTM. Both software
programs are designed to be complementary to one another. A large number
of calcualated examples have shown that already COPRA DTM has been
providing surprisingly good results about longitudinal and transverse
strain values caused by the roll forming process. Therefore it is a
logical thing to use this proven software tool as a pre-processor fro
the Finite Element Analysis in COPRA FEA Roll Forming. The sequence in
this process chain looks as follows:
In a first step the user designes the different forming steps (flower
pattern) using respective COPRA software features and optimizes his
designe by means of COPRA Deformation Technology Module (DTM). In case
of critical shapes or high demands on accuracy COPRA FEA Roll Forming is
able to import these data without addtitional modification. Most of the
parameters required are defined automatically (taken from COPRA DTM)
without the need to be an FEA expert.
Benefit for Tube Producers, Custom Roll Formers
and Machine Makers
Due to the fact that the non-linear solver in COPRA FEA Roll Forming
has been designed specifically for this range of application the
computing time required is limited. This is - especially for the
practical use - very advantageous. The operator is able to calculate a
complete set of tooling within one night - on a standard personal
computer (which has to be equipped with some RAM memory - of course...).
This makes the solution suitable for a parical use in the daily work and
opens new possibilities for the tube producer as well as for
a roll forming company. Automotive companies, for example , are
interested in getting strainreduced tubes as a semi- finished product
for the subsequent hydro forming process. Custom roll forming companies
will be able to predict possible defects or weak points with a much
higher accuacy than before and thus be able to optimize their
products effectively.
Also machine making companies will be able to
profit from this new simulation technology because they will be able to
do a much more sophisticated construction than before.
FEA-based simulation of the
rollform process
A continuous development of our products is the key for our success
COPRA FEA-Rollforming is actually
already the fourth generation of a calculation- and simulation software
for the rollform process within the COPRA product family.
It all began in 1987
with the simple calculation of the theoretical elongation of the strip
edge (strip edge strain)
As this calculation method (that
is sometimes still used today in commercial software packages) already
fails for a simple U-channel with a bead (see figure below), data M very
soon developed the so called wire frame model.
1987: Calculation of the strip edge strain
In case of the calculation of the strip edge strain only a
non-problematic part of the section is taken into account while the area
of highest elongation is not taken into account.
1989: COPRA Wire Frame Module
The basic reason for the
development of the wire frame model was not a nice 3-dimensional
representation of the forming process but the visualisation of the
theoretic elongations in any position of a section. By the way - this
calculation method is – together with other features – still today
part of the COPRA software package "Flower Technology" and
offers the user with lower requirements the possibility of an easy and
effective flower design.
Every user of a rollform software can
determine by himself if the program he is using is based on a linear
statement (i.e. according to the old triangle statement) or if it takes
into account parameters like shape of the section, roll diameter,
distance of horizontal centres and forming rolls (i.e. top-, bottom- or
side rolls). While the roll diameter has a substantial influence on the
resulting longitudinal elongations (rolls with small diameters cause a
more extreme curvature = higher local elongations), the distance of the
horizontal centres is of minor importance (the forming length depends on
other factors). If e.g. the roll diameter is modified the user should be
able to recognise a substantial change of the respective diagrams and
verify the results directly on the machine.
This term actually has its origin in a
research project in which practical rollform tests executed at the
Technical University of Darmstadt should be evaluated how the results
could be represented in the computer. Mr. Albert Sedlmaier (research
engineer at the Technical University of Munich and founder member of the
company data M) has co-worked on the computerised representation of the
deformation areas in rollform lines during the late eighties. This
method allowed an analysis of practical rollform tests for the
determination of characteristic numbers. Based on this research results
data M developed a simulation of high reputation for the calculation of
the longitudinal and transverse elongations during the rollform process:
the COPRA Deformation Technology Module (DTM).
1994: COPRA
Deformation Technology Module
The COPRA
Deformation Technology Module takes into account parameter like roll
diameter, roll position, type of material, material thickness, section
shape etc. and calculates an idealised deformation curve. For the first
time it was also possible to determine the elongations in the centre of
the material (homogeneous strain) as well as on the upper and lower side
of the material (inhomogeneous strain caused by material thickness). The
program were calculating the longitudinal elongations more exact than
any other commercial rollform software.
COPRA DTM had a very
quick market success. The reason therefore were the quite good results
and the short calculation times being in the range of minutes. A serious
number of users preferred this calculation although they had already
been using a Finite Element calculation (especially steel producers).
The main reason for that were and are the extreme long calculation times
of today’s available non-linear FEA-systems. An FEA-based calculation
like that may still last – depending on the section and the hardware
used – a few days up to several weeks.
2000: COPRA
FEA-Rollforming
But if the target is to
find out more about the occurring forces, driving torque or the actual
shape of the section in the individual passes a geometric statement is
not sufficient. For applications like e.g. the hydroforming process it
is very important to know the stress distribution inside the final
section to determine the remaining formability. At data M premises
extensive tests with non-linear FEA-based calculations have been and are
performed already for a long time – unfortunately all with the result
of excessive calculation times.
For this reason the
company data M Software GmbH has developed together with a company being
specialised on FEA based calculations an FEA-model supplying the above
mentioned results. This new simulation software is called COPRA
FEA-Rollforming. The proven simulation software COPRA DTM is not going
to be replaced but will be the postprocessor for the additional
available Finite Element simulation. The FEA-based simulation was
especially designed for the rollform process and is therefore very easy
to use.
Because of its close
connection to the COPRA data base the FEA-based model allows an
optimisation exactly in those places where it seems to be necessary for
the individual problem. This speeds up the calculation and simplifies
the use.
And in addition the
FEA-based rollform simulation will also be affordable for medium sized
companies.
Profitable stock roll
management
The COPRA Database
Management System – containing all necessary product information –
is the centre of the individual elements of the process chain "roll
forming". During the design process this simplifies not only the
localisation of similar profile shapes (similarity retrieval via Fourier
analysis) but also the administration of the stock rolls. Because a
common data base is available the processing time and the error rate
will be improved.
Part of this process
chain is the COPRA Roll Scanner, a contactless (optically) working
measuring device for turned parts. This fully automatically working
machine not only provides possibilities for process data and stock roll
management, but also for a continuous quality control of the used
tooling. The nominal size and shape of a roll saved in the data base is
compared with the scanned contour and the result printed in a quality
report. This way the user is provided with a verification of the
dimensional accuracy of his tooling with every scanning of a roll.
More information can be
found in an article of "forming and fabricating" or
"international sheet metal review" on this subject. We would
be pleased to send you a reprint of respective article.
COPRA Roll Scanner 200
data M Software GmbH now
offers a new Roll
Scanner called Type 200 for a price less than 100.000,- DM. This
measuring device is based on stone cradle, has got two controlled axes
and is applicable for roll diameters up to 450 mm (18"). The COPRA
Roll Scanner is delivered with a network interface and COPRA-/DXF-interface
as standard equipment.
COPRA Roll Scanner 200, principle
outline
Services supplied by data M
Beyond powerful software programs for the
sheet metal and rollforming industry the companies data M Software +
Engineering also provide additional services you can take profit from:
- Professional training courses for an
efficient use of our sheet metal CAD/CAM software packages
- Workshops for the improvement of your
knowledge – also based on user defined requirements. Feedback of
one of our customers: "after joining a workshop for the
rollform simulation we were able to take profit from the
possibilities of the COPRA Rollform Software. The 4 sections we had
to make in the meantime worked without a subsequent modification of
the rolls".
- Analysis and reengineering of existing
roll sets with our optical measuring device, the COPRA Roll Scanner
(which we are of course also selling). The COPRA Roll Scanner comes
with a data base interface. The scanned rolls as well as the profile
sections can be stored in a data base. On top data M also supplies
automated software solutions for quality control and repetition part
retrieval.
- Reworking and optimisation of existing
roll sets
- Roll design services with and without
roll manufacturing
- Software development services for
automation and image processing problems
Thank you for visiting data M. If
you have any comments or if you need more infos please contact us: mailto:datam@datam.de
And don't forget to bookmark this web-site if you find it interesting.
data M Software GmbH
Am Marschallfeld 17; D-83626 Valley; Germany
Phone: +49 8024 640-0
Fax: +49 8024 640-300
All material on this web site is copyright © 1998, 1999 data M Software
GmbH, data M Engineering GmbH, Germany.
All rights reserved.
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