Brief Summary of Project and Findings
Current & Future Technologies in Automotive Engineering
Simulation ( CAE )
The intent of AUTOSIM was to provide ideas to make more
efficient use of engineering simulation techniques, particularly in
structural analysis and computational fluid dynamics. AUTOSIM had 2
complementary aims: firstly to review Best Practices, and secondly,
to identify the most promising potential Breakthrough Technologies.
The consortium consisted of 32 companies (OEMs, Tier 1 + 2
suppliers, software developers, researchers and consultants).
These objectives have been examined in three key technology
areas:
- Integration of simulation into the design process
- Materials characterization
- Improved confidence in the use of simulation.
Whilst these 3 key technology areas are important by
themselves they are not isolated but strongly connected to each
other.
Awareness Statement
The participants of the AUTOSIM project recognize and acknowledge
the importance of other topics as well, which could not be covered
within the project due to limited time and funds. Examples are
Durability, Computational Electromagnetics, Performance,
Mechatronics, the Human Factor etc.
“Integration”
Within “Integration” up-front simulation is a key
driving force behind today’s necessary paradigm shift in new
product development. Conventional product development methods are
too inefficient. The traditional “design-analyze-build
& test” scenario will not remain competitive.
Today, leading organizations perform simulation at the concept
stage to explore design alternatives, detect flaws, and improve
product performance before a detailed design or a physical
prototype is created (simulation drives design).
“Materials”
Main obstacles in materials characterization in the concept design
phase are missing decisions about material selection including
missing relevant test data, insufficient and inaccurate geometry
information, guidelines in terms of modeling techniques etc.
The quality of materials characterization will increase when
development proceeds.
But one needs to keep in mind that “simple material
models” omitting important effects might cause wrong
simulation results and therefore wrong design choices. This applies
e.g. to material’s strain rate sensitivity in the prediction
of crashworthiness behavior or the consideration of bifurcations.
Involving suppliers in the earliest design phases might be crucial.
Also “cost constraints” have to be acknowledged. Cost
comprises of many aspects including data generation (testing, data
capture and validation / QA) and material model development.
“Confidence”
Confidence has a significant influence on the uptake and use of
CAE models. It is reliant on good material information and is
necessary for the successful integration of CAE within the design
and engineering process. It is also dependent on the available
time, resources and budget. Without confidence a CAE model has no
obvious benefit or value.
CAE confidence is influenced by a broad variety of topics. Based on
discussions within the AUTOSIM consortium the items
- Physical model
- Human resources and organization
- Data validity
- Digital model
have been prioritized and discussed in more detail.
How to move on?
Perspectives and expectations have been discussed within the
AUTOSIM project which need to be considered today and in the near
future. There are lots of tasks which need to be fulfilled to
become more efficient in terms of making key decisions more
precisely and earlier. Some of them are listed below:
1 Efficient deployment of Digital Prototypes
2 Becoming faster in the Conceptual Design Phase
3 Clearly defined Materials Characterization Methodology
4 Accelerating the Model Preparation Phase
5 Robust Design and Complexity Management
6 Current Status and Future Trends in CFD
7 Design – to – Cost
Starting with item 1
this applies to streamline processes in a concurrent engineering
environment using digital prototypes in an efficient way.
“Up-front loading” will require a paradigm shift to do
analysis earlier and faster and / or to leverage knowledge from
previous designs using product- and simulation data management
systems. The vision: simulation drives design (item 2
).
A clearly defined materials characterization methodology would
permit new materials (data and models) to be adopted with increased
confidence (item 3
).
Model generation systems should provide capabilities for
cleaning-up and de-featuring CAD geometry. It also should be
possible to assemble and connect component models from different
sources. The recognition and meshing of important features are
required like boundary layer modeling for CFD. Polyhedral
meshing contributes enormously to the ease of volume-mesh
generation, accuracy and robustness of the CFD solution (item 4
and item 6
). Multi-domain meshing is essential for certain types of
multi-physics analysis such as conjugate-heat-transfer or
fluid-structure interaction.
Based on the results of stochastic simulations or
multi-disciplinary optimization or test interactive process maps
can be developed which give the user an integrated view of the
degree of coupling, global robustness measures and complexity (item 5
). The intensity of correlation between input and output
parameters can be highlighted by various means e.g. different
colors, line characteristics and the distinction between direct and
indirect correlation.
Affordability is one of the key issues for design engineers and
manufacturers of new car body models. Sometimes vehicle development
projects failed to enter the production phase because cost could
not meet the project financial targets. Likewise vehicle projects
went into production with severe cost and manufacturing constraints
but failed in the marketplace because of limited improvements
in vehicle functionality or performance. Either case primarily is
due to the lack of understanding of the cost and performance
relationship and engineering alternatives during the vehicle
development cycle (item 7
).
Summing up
: in the future, CAE needs to take into account extended
distributed development environments to address Product Life Cycle
Management. Tools and Processes must be integrated, with the
consideration given to the OEMs and Suppliers, recognizing their
knowledge and resources.
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