The final design uses a Double Wishbone front suspension system'The design incorporates horseshoesha

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MECH 460 Team Design
Project 2006 AUTO21 Electric Car Suspension
Design Sean Lefort, Joris de Wit Trevor
Kidd Supervisor Dr. Il Yong Kim
AUTO21, a Canadian automotive industry research
company, has decided to analyze collaboration as
it occurs among teams working on an automotive
project from widespread locations. To support
this analysis, an electric car design project was
initiated. The objective of the project is for a
set of seven Canadian universities and two
companies to design a two-passenger electric car,
and evaluate the collaboration tools as they are
used in the process. As our team enters the
project in September of 2006, we are asked to
design the front suspension for the vehicle. We
use design criteria focused mostly on vehicle
handling, comfort, and compatibility with other
components in the vehicle. Through stress
analysis and three design iterations, the final
design in Figure 2 was reached.
ABSTRACT
FINAL DESIGN
COLLABORATION

• The final design uses a Double Wishbone
  front suspension system. The design
  incorporates horseshoe-shaped control
  arms for maximum support against all
  four significant tire forces normal,
  braking, traction, and lateral. The lower
  control arm has a stabilizing piece
  incorporated into the design to
  increase the rigidity of the system. The control
  arms attach to the chassis in a manner
  which allows full rotation, much like
  hinges. The arms connect to the wheel motor (not
  shown in Figure 2) with ball joints to
  allow for steering.
• The material used in the control arms is
  4130 chromoly steel. This material was
  chosen because it is highly durable and has
  good stiffness and fatigue
  characteristics. It performed well in
  the ANSYS stress analysis and is also
  very accessible for reasonable cost.
• Two preliminary control arm designs were
  developed and stress analysis was performed on
  both
• designs. One design was a square-edged cast
  model with channels to decrease weight and it did
• not perform well in preliminary stress analysis
  with CAD software. The other original design was
• analyzed using ANSYS stress analysis software and
  the results can be seen in Figures 3 and 4

AUTO21 channels its efforts into making
contributions to the Canadian automotive industry
through conducting research on current industry
practice. In the automotive industry, factory
locations are often scattered around the world
and thus, effective collaboration among these
locations is vital. The true objective of the
ECD project is to evaluate the collaboration
methods used by the teams located at different
universities and companies. The communication
tools used in the ECD project are TWiki and
TeamCentre Community (networking tools), e-mail,
MSN messenger, and live meetings. Our team
discovered that TWiki was a great tool to use for
broadcasting project information and we recommend
to General Motors to replace their existing tool,
TCC, with TWiki. E-mail and MSN was useful for
more local collaboration however, for global
collaboration, TWiki was invaluable.
Figure 2 Front Suspension
STRESS ANALYSIS
BACKGROUND
RECOMMENDATIONS
The Electric Car Design (ECD) is a two year old
project funded by AUTO21, a Canadian Network of
Centres of Excellence. The project is a
collaborative effort including seven different
Canadian universities and two companies, namely
General Motors and the ABC Group. The goal of
the project is to produce the manufacturing plans
for a two-passenger, drive-by-wire electric car.


As undergraduate students
joining the project, our team was assigned to
develop some recommendations, including a
detailed CAD drawing, for the front suspension
system of the vehicle. The main objective was to
replace the standard upright with an in-wheel
motor and design appropriate control arms and tie
rods to reinforce the system.
The final design as it attaches to the
wheel motor, as well as the
given hardpoints (blue), can be
seen in Figure 5. Due to time constraints
of the project, we were only
able to develop three design iterations
and thus the final design may not
be entirely optimal. However, it is noted that
the ECD team does not foresee the car undergoing
mass production, and thus our design would be
perfectly suitable for a prototype. It is our
recommendation that if the car is to be mass
produced, research should be performed to further
optimize the shape and size of the system, as
well as some work to determine manufacturing
costs and capabilities. Our team would like to
thank our Faculty Supervisor Dr. Il Yong Kim, as
well as graduate students Kiumars Jalali, Shane
Smith, and Farouk Saleh. Their time and effort
is greatly appreciated.
Figure 5 Suspension with motor.
Figure 4 Upper control arm.
Figure 3 Lower control arm.
Figure 1 Rough CAD drawing of the Electric Car
Design.
DISCUSSION
ACKNOWLEDGEMENTS
Industry Advisor AUTO21 Research AUTO21
401 Sunset Avenue Windsor,
Ontario N9B 3P4 Other Companies GMC
Canada and the ABC Group.
Department of Mechanical and
Materials Engineering Faculty of Applied
Science Queens University
Kingston, Ontario K7L 3N6