Deploying ANSYS models as Enterp by ps94506


									 Deploying ANSYS models as Enterprise Accessible Software

                                         Sebastian Dewhurst
                                Vice-President, Enterprise Applications
                               AEA Technology Engineering Software Inc
                                    Omega Centre, Pittsburgh PA
                                 +1 800 529 3810 or +1 412 893 1005

                                           Derek Sweeney
                                  Managing Director, IDAC Ireland Ltd
                               18 Windsor Place, Lower Pembroke Street
                                    Dublin 2, Ireland, 01 676 3765
Obtaining more value from an organisation’s assets and knowledge is on every manager’s agenda. This paper
presents AEA Technology’s developments in enabling organisations to capture expert knowledge, simplify the user
interface and extract more value from their existing complex software in a quality controlled environment.

The use of EASA with ANSYS is explained with an example of a medical device application developed by IDAC
Ireland Ltd. This application calculates the fatigue life of a medical stent. A stent is a small medical device, which is
used to treat coronary and other blood vessel disease. It is deployed inside the diseased artery and acts as scaffolding
to ensure free flow of oxygenated blood. EASA has brought benefits to this application by allowing the rapid
development of a GUI, web deployment and much easier use of the application by non-ANSYS users within expert-
designed boundaries.

Customized GUI, enterprise applications, web-enabled, knowledge management, user interface.

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This paper presents AEA Technology’s EASA (Enterprise Accessible Software Applications), a software tool that
enables organisations to extract more value from their existing software models in a quality controlled environment.
It then goes on to describe how ANSYS and EASA have been used together on an important medical application.
Most technically oriented organisations use high performance generic software such as ANSYS to produce models
that represent their products and applications. Although some of these models may be of general interest to a range
of personnel across the organisation, it is likely that each model will only be driven for each solution by the person
who originally produced the model.
Up to now, if wider application of a model is needed, an organisation usually has to take one of two routes:
1) Teach more people how to use the native software (e.g. ANSYS) and how to successfully obtain accurate
   solutions from the models.
2) Commission and produce a tailor made Graphical User Interface for the application, normally using C++,
   VisualBasic, Java or, where applicable, using the code’s own GUI building tools .
These models can be successfully applied with “User Pull” – where the potential users see the application being used
by the “expert” and develop an appetite to run the models for themselves with their own input data. The easiest
models to share are those that are easy to “parameterise”, as the geometry model, input options and physical
properties can be defined across a range where good solutions can be assured.
In recent years, AEA Technology has been successful in producing specific “vertical application” products, which,
although based on the CFX fluid dynamics code as the engine, provide the user with a simple user interface into
which “engineering level” parameters are entered. This means that the user does not therefore have to know how
CFX works to obtain the solutions they require. Examples of these include “ProMixus” and “TankSim”.
In producing such applications, AEA Technology started the process of developing tools and techniques for rapidly
producing vertical applications, with Graphical User Interfaces, that drive underlying software. AEA Technology
developed these tools and ideas further, with the mind shift that any organisation that uses complex software could be
able to develop such vertical applications for themselves. The idea is that web-based applications could be
developed by an organization under its own control for additions and revisions. We then had the EASATM concept –
Enterprise Accessible Software Applications, which was launched as a software product in October 2001.

The EASA Concept
EASA provides a complete and generally applicable environment that allows application experts to easily and
quickly author "GUI templates" for popular problems, releasing key parameters to be changed by other users, who
see the version-controlled EASA applications (EASAPS) on the Intranet or Internet using a browser on their
computer. EASA will work with any batch-capable software, such as ANSYS.
Figure 1 shows a typical tabbed pane from a GUI, with a dynamic diagram that changes its shape and size in
sympathy with user inputs and user input parameters. Images are defined by the author – either by linking the EASA
Application (EASAPTM) to a .GIF or .JPG file, or by creating diagrams using the tools provided. Authors can limit
the range of allowable inputs either to absolute values or using expressions linked to other parameters – these appear
as “tips” as shown close to the “inlet height” box on Figure 1.

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Figure 1           Typical EASA Application or “EASAP”

CFD experts might author furnace models, cyclone models and heat exchanger models; structures experts might
author I-beam calculations and pressure-vessel calculations; and an environmental specialist might author a generic
plume dispersion investigation using an in-house code. The author uses his skill and experience to ensure that the
applications operate successfully over a defined parametric range, which is encapsulated into the EASAP.
Non-software-experts can then access EASAPS over the corporate Intranet with a Web browser, saving them the
time needed to become experts in the underlying complex applications and saving the expert from having to run
different parameters in the generically applicable models.
By taking this approach, EASA allows an organisation to define its own set of vertical applications on the software
assets it already owns, capturing expert knowledge in an easily re-usable form and deploying it over the intranet /
internet for others to use.
EASA also makes it very simple to carry out parametric analyses – the user simply selects the range across which
solutions are required, the EASA server schedules the runs and brings the results back into web-pages which allow
the parametric results to be analysed. This type of work can be very time-consuming both to set up and to analyse
using traditional methods of running the applications.

How does EASA work ?
The EASA software is a Java client-server environment, in which the information needed to run a particular software
code is locked into a JAVA applet by the EASAP Author.

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EASA can drive any batch-capable software and contains the necessary structures to run jobs on different computers
(where the software applications are resident), control licensing associated with the specialist software and serve up
web-pages to the system users. Figure 2 shows the basic hardware layout – users with browsers and a Java run time
plug-in, the EASA server and pre-existing compute servers where the codes to be driven are resident.

Figure 2           Typical EASA installation and application galleries

The Java applets are very small files, suitable for rapid internet transfer using standard modem technology, which
contain the configuration information for the graphical user interface. On selecting an EASAP, the user downloads a
copy of the applet to the local PC, enters the parameters as necessary, then submits the run – which transfers a
configuration file back to the EASA server. The EASA server then selects the computer to carry out the processes –
which can be several in sequence as specified in the EASAP (e.g. Pre-process, Solve, Post Process). The EASA
server then carries out the post solution analysis of the output files and posts the results back to the user’s own results
The results pages are specified within the EASAP by the Author – they can contain text, extracted tables from the
output files of the underlying application, images or AVI files generated by the application. Therefore this captures
the experience of the author in appreciating which information from the application’s output files is important to the
end-user and how best to present it.
Figure 3 provides a simple example of EASA output for an ANSYS Verification Library example.

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Figure 3           Example Output Web-Page from EASA

How does the Author Set up the EASAP?
The authoring tools are a particularly powerful part of the EASA system. EASAP Builder provides a tree structure
for building the EASAP and publishing it on the Intranet. No knowledge of Java is needed to produce an EASAP.
Figure 4 shows an example of an author’s tree for a typical EASAP. The tree structure contains four main elements –
EASAP Properties, User Interface, Processes and Output. Each element has a set of Essential or Optional
Parameters which appear on selection of the element. Full error checking and preview facilities are built in to give
the author maximum confidence in building the EASAP.
EASA is connected to codes such as ANSYS by setting up the compute server configuration section of ANSYS. This
is quick and easy to achieve, since the information needed is the information that the software expert already uses to
drive the underlying software in batch. As an example, for ANSYS, the Environment Variables need to be set as

set Path=C:\WINNT\SYSTEM32;"C:\Program Files\Ansys Inc\ANSYSED57\bin\intel"
set ANSYS57_DIR=.\

With these environment variables set, an EASAP can use ANSYS simply by entering the normal ANSYS < input.dat
> output.dat in the EASAP processes section.

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Figure 4           EASAP Builder – typical screen

EASA provides a version control system for the EASAPS – allowing them to be developed “off line” by an Author,
then, when ready, to publish them on the Intranet. Any subsequent versions are then automatically given revision
numbers – minor or major as selected by the author, see Figure 5. Previous versions of EASAPS can be restored by
the system administrator and EASAPS can be automatically upgraded to run with the latest version of EASA.

Figure 5           EASAP Configuration Management

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Using EASA with ANSYS – a Medical Application
A good example of an EASAP using ANSYS has been produced by Derek Sweeney of IDAC Ireland. This
application uses ANSYS to predict the fatigue life a medical stent. Stents are small medical devices which are used
to treat coronary and other blood vessel disease. They are deployed inside the diseased artery and act as scaffolding
to ensure free flow of the oxygenated blood.
A good stent design must have appropriate compliance characteristics (it must be easily deployed, but have sufficient
radial strength to support the diseased vessel wall), good margin against fatigue, must not exceed ultimate strain
during deployment. Depending on the specific application, there will be other requirements, but these are
fundamental to most stent designs. These requirements are often conflicting. For example reducing compliance will
typically reduce alternating stresses which cause fatigue, but will also tend to increase maximum strains during
manufacture, which will result in higher residual stresses. FEA (Finite Element Analysis) provides a time and cost
efficient means of assessing multiple designs in an effort to identify the optimum design, which satisfies all
In addition, it is a FDA requirement that FEA be carried out to assess the fatigue life of any stent which has been
submitted for approval.
This is a complex simulation involving intricate geometry and material and contact non-linearities. Such an
application would normally be the domain of the Finite Element expert. IDAC Ireland Ltd have developed a vertical
application which allows stent designers to carry out complex stent simulations. This has been implemented as an
EASA application. All of the data required to run the simulation is extracted painlessly from the designer through the
GUI. The stent FE model is automatically built and submitted to ANSYS for solution. Fatigue margins and other
structural data are calculated and reported automatically in an html report (see Figure 5). The EASA software
manages the process.

Figure 5           Screen Shots from Medical Stent Application

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Next Steps
EASA has already been developed to use Java 3D, so a near-future release will allow 3D dynamic diagrams in the
EASAPS (see Figure 6). Optimisation routines will also be released in a future version, to allow the User to specify
the required output or constraints, to allow EASA to find the design inputs that correspond to those outputs.

Figure 6           3D Dynamic Diagram in an EASAP

Enterprise Accessible Software Applications (EASA) has been developed to help organisations simplify the interface
to batch-capable software that is difficult or complex to learn and use. The approach used helps capture expert
knowledge and present it in a quality controlled and fully web-enabled environment for sharing within and between
organisations. The overall objective of EASA is to allow organizations to obtain more value from their existing
software-related assets.
Our experience is that this is something that organisations have been wanting to do for years, but it is only now, with
the types of IT infrastructures found within modern organisations and the EASA environment, that applications such
as IDAC Ireland’s ANSYS stent model can be made generally available over an internet or the internet.

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