State of the art mechanical design requires state of the art solutions.
P.
Arras,
D.
Van
Merode,
C.
Peeters
Campus De Nayer, department of Engineering Technology,
Lessius university college, Zandpoortvest 13, Mechelen, Belgium
Email: peter.arras@lessius.eu
Abstract
This contribution presents the present state of design tools for mechanical engineering & design
and reviews the results of the Tempus PROMENG‐project with respect to mechanical design
tools.
Keywords
Design, engineering, CAD/CAM/CAE, Tempus PROMENG
Introduction
Time to market in industry has become an hot item to produce and sell new products in an
economic beneficial manner. The 21st century economy moves faster than ever before, and
product innovation and changes have become a daily routine in production and thus in design.
Furthermore, globalization of the economy and the fierce competition on the market with other
players puts pressure on all levels of production and product development in a nowadays
company.
The ultimate design aspect of a product isn’t changed yet: designs needs to result in a set of
data for the production of the product. However, the tools for designing have changed
dramatically over the last 20 years and are now readily available to any engineer.
This article will discuss the design solutions for mechanical design which is promoted in the
Tempus PROMENG project to renew and improve curricula for engineers in Russia, Ukraine and
Uzbekistan.
Results and discussion
PTC’s Creo Elements as a design solution for complete mechanical design
Design has shifted from drawing‐oriented design from the past to model‐oriented design
nowadays. In drawing‐oriented design, the technical drawing was at the center of the design
and contained a lot information. Besides the technical drawing, many other documents had to
be included to contain all necessary information on a design, whether it was calculation reports,
material properties or tolerance models of the design. In a model‐oriented approach, as is used
in 21st century engineering design, the model itself is at the center of design. The idea is to make
a virtual prototype of the design. A virtual prototype is the representation of the design on the
computer with all properties of the real design. Virtual prototyping opens opportunities to
Creo and Creo Elements, design solutions from PTC (Parametric Technology Corporation) (1)
offer a solution for mechanical design without any compromises on functionality and tools. The
aim of the software is to enable first time right design. In first time right design, we try to
eliminate all errors preliminary to the first prototype or production. Therefore, a large amount
of analysis tools are available in the design tool, to ensure solid and secure engineering. As we
see in figure 1, the number of engineering tools available in the design solution is almost
unlimited. At the heart of it, is the design database, the CAD‐model. These data are reused in all
other applications to ensure data integrity and ease of use.
Figure 1 model oriented design
Applications in engineering range from making documentation, like making traditional technical
drawings of the design, to numerical simulation for the calculation of forces, strength and
dynamic behavior. All of this is done starting with the CAD‐model, without having to physically
build the design for testing. This presents an enormous gain in time and costs ‐ since no (or not
so many) physical prototypes have to be build ‐ and leads up to a first time design.
In visual representation, it can be virtual pictures of the prototype or animations of a
mechanism, to including light and appearance studies using rendering techniques.
Here we present two examples of the flow of data through different applications to clarify the
model oriented design. The first example is about a plastic ice‐cream spoon.
At first the product will be designed (CAD‐model) with all of the properties of the real model. As
we see in the diagram figure the terminology “properties” spans a wide range of different
virtual
prototype=
CAD
model
production
CAM
documentation:
drawings
BOM
numerical
simulations:
structural,
thermal
mechanism
analysis
geometry
checks
tolerance
analysis
visual
represen
‐
tation
aspects. Geometry is the graphical representation on the computer (shape) of the design, but
also contains vital information for production as there are dimensional and geometrical
tolerances, and surface finish.
Figure 2 CAD‐model is a real virtual object
The physical and mechanical properties inform the system about the material of the design, but
next to it, contain the structural and thermal properties, as there are Young’s modulus, yield
stresses and thermal constants. For dynamic behavior properties include aspects like
mechanical damping and fatigue behavior.
Figure 3 model of the plastic spoon
Figure 4 CAD model of the spoon and technical drawing
Model containing the geometry of the plastic
spoon with dimensions/tolerances and
physical properties.
Technical drawing of the spoon for printed
communication to production. Drawing containing
section, dimensional information and other product
specifications. virtual prototype: CAD Model geometry appearance physical and mechanical properties dynamic behavior
Figure 5 stress and strain calculation of the spoon
Structural strength calculation of the spoon is done to verify strength and structural behaviour.
If the spoon is not strong enough, design iterations can be considered. By changing dimension
values, or by structural redesign of the product, an optimized shape can be found.
Figure 6 mold for plastic molding of the spoon
The same association between model and application exists for complex designs build from
some or many parts. The second example is the compressor head of on air compressor. Both
examples are used in the curricula developed for Tempus P ROMENG.
In the CAM (Computer Aided
Manufacturing) module, tool paths for
the production of the mold are prepared
Figure 7 virtual model of an air compressor and compressor head
The mechanism of the compressor can be analysed and calculated for mechanical stress.
Figure 8 mechanical stresses in the crank of the compressor head.
The examples show only some of the possibilities embedded in modern design software tools.
Tempus PROMENG: PRactice Oriented Master Programmes in ENGineering in RU, UA,
UZ. (20102013)
The Tempus programs from the European commission supports the modernization of higher
education and creates an area of co‐operation in countries surrounding the EU. Established in
1990, the scheme now covers 27 countries in the Western Balkans, Eastern Europe and Central
Asia, North Africa and the Middle East. In the Joint Projects action, partnerships between higher
education institutions in the EU and partner countries are promoted. They can develop,
modernize and disseminate new curricula, teaching methods or materials, as well as boosting
quality assurance and management of higher education institutions. (2)
1. Review / analyze / upgrade the current curricula in Electrical Engineering (MA) according
to recent advances in the target field;
2. Therefore develop four new generic curricula concerning
o Applied informatics and data transmission systems; CAD /CAM/CAE for Electrical
Engineering;
o Quality Engineering;
o Environment management and Engineering.
3. Retrain academic staff in the new curricula methodologies / train of the non academic
teachers / mentors from partner enterprises;
4. Pilot teaching / operation;
5. Establish ELM Offices (Engineers in Labor Market) with stakeholders support.
The PROMENG project – a 3 year project ‐ has defined new curricula for engineering studies in
electro‐technical engineering. Definition and development of the curricula was done in
collaboration with the partner universities in the first year of the project. The second year of the
project was used to install the laboratories at the partner universities and to distribute the
curricula and courses amongst the partners. Also a summer school was organized to train
teaching staff of the partners in the use of the design methods and materials provided.
The Tempus PROMENG project promotes the use of ProEngineer/CREO (from PTC) as the state
of the art design solution for mechanical CAD. Every partner university in the project is offered a
CAD laboratory (existing of 12 computers) and the necessary licenses for the use of CREO‐
Elements/Pro with their students. Moreover partners at the same time get licenses for the ECAD
(Electronic design) software, Altium Designer (4), for the electronic engineering students.
As such, students can work with high‐end design software to complete their studies on
mechanical (and electronic) design. At the same time, the project proposes curricula and
provides course material with examples and tutorials to help the partner universities with at the
start of the use of the new curricula. Students are motivated to start using the system, and are
entitled to the free use a of school version of the design tool.
Figure 9 Creo/elements possibilities. design: CAD‐ model Technical drawing Numerical simulation Mechanism analysis Finite element analysis Geometrical checks Tolerance analysis Interference and clearance checking
Figure 9 represents the scheme on which the MCAD‐curricula is build. All engineering tools for
designing and checking the design are available to students for use in their designs. As we can
see, the construction of the CAD‐model, is only a small part of the design effort. In first time
right design, the checks and calculations on the model are the most important tools.
The so‐called “Aberdeen groups study” showed that companies leveraging three or more
different types of simulation before actual production of parts are able to reduce the number of
prototypes by 37%. (5)
By providing simulation tools, as there are mechanism analysis tools and finite element analysis
tools, the engineering design competences of the students can now be improved and raised to
21st century standards.
Conclusions
Mechanical design techniques switched from a drawing‐oriented to a model‐oriented approach.
The design model in the CAD‐database serves as a virtual prototype, containing all properties of
the real object. This approach enables engineers to virtually check their prototype to eliminate
possible mistakes. These design techniques are part of everyday practice in the industrialized
world. They lead to a shorter time on to market and as such to a more profitable way of doing
business. To help partner universities in former USSR‐countries to restructure engineering
studies towards a more nowadays approach, in the Tempus Promeng project western partners
help out the partners in the east and in Central Asia to implement these techniques in their
engineering degree studies. Curricula, course material and infrastructure is provided to give
partner universities a head start in starting teaching state of the art designing techniques.
References
1. PTC. [Online] [Cited: 09 10, 2012.] www.ptc.com.
2. European commission. [Online] [Cited: 01 20, 2012.] http://ec.europa.eu/education/external‐
relation‐programmes/tempus_en.htm.
3. TEMPUS PROMENG. [Online] [Cited: 09 20, 2012.] http://www.promeng.eu/index.php/about‐
promeng.
4. Altium. [Online] [Cited: 09 10, 2012.] www.altium.com.
5. group, Aberdeen. Engineering Evolved: Getting Mechatronics Performance Right the First
Time. s.l. : Aberdeen group, 2008.
Contact and links.
Ing Peter Arras
Lessius university college, Belgium
Peter.arras@lessius.eu
Ing Dirk Van Merode
Dirk.vanmerode@lessius.eu
Ing Chris Peeters
Chris.Peeters@lessius.eu
Uzbekistan partners:
Fergana Polytechnic institute, contact Prof. Zair Usakov
Karshi Engineering‐Economic Institute, contact ass. Prof. Ziyovuddin Nazarov
Tashkent State Technical university, contact Prof. Zair Shamsiev
