UWE Bristol Engineering showcase 2015

Jamie Boxshall
Meng (hons) Mechanical Engineering
Project Supervisor
Rui Cardoso
Introduction
The wheels on the Bloodhound SSC are a critical
area for analysis; the rotational velocity is so great
that rubber wheels would simply disintegrate and
a steel rim would be so heavy that the inertial
forces would tear them apart.
It has been decided by the Bloodhound team that
the wheels are to be made from a solid aluminium
alloy, it was discovered during last year’s report
that the stress throughout the wheel from inertial
forces are within a FOS of 1.5. This is a low FOS
however with the design they used, the
compromise was the more material required to
strengthen the wheel, would in turn, increase the
inertial forces and hence the stress.
This report sets out to evaluate the stress
throughout the wheels, from both inertial forces
and applied weight on the wheels. This will be
used to discover if the solid aluminium wheels are
strong enough to carry the load of the vehicle
across the desert at 1000 mph and further more to
discover whether composite materials could have
been used in replacement of the aluminium
wheels, assuming money and time is not an issue.
The decision to undertake this project was due to
a strong underlying interest in the Bloodhound
SSC, as well as an interest in stress analysis.
Investigation into the design optimisation of the wheel on the
Bloodhound SSC
Validation
To validate the Results of the FEA a comparable set
of results was produced through practical testing
The practical test tested a car wheel wired and
strain gauges to out put strain during driving load,
the results showed a clear fluctuation of stress as
the wheel rotated about entering high and low
stress regions. When compared to the FEA result
the strain showed a close reltionship to support
the FEA model.
Bloodhound
Finite element analysis on the wheel then began
and the stress distributions plotted, shown below.
Composite
The bloodhound wheel was evaluated for comThe
use of composites for the design of the
bloodhound model may very well be possible,
however using the current FEA model no such
conclusion can be made as the stress indicated
that the material will fail and no optimal design
can be produced as a result.
Conclusion
The composite models showed that weight savings
could be made but the stress levels are so high
above the material strength that it is unclear
whether the changes would have been able to
safely withstand the induced load.
Therefore no solid conclusion could be made and
further investigation should be under taken
Project summary
This report set out evaluate the stress
throughout the wheels, from both inertial
forces and applied weight on the wheels. This
will be used to discover if the solid aluminium
wheels are strong enough to carry the load of
the vehicle across the desert at 1000 mph
and further more to discover whether
composite materials could have been used in
replacement of the aluminium wheels
Project Objectives
The purpose of the investigation is to discover
whether the wheels on the Bloodhound SSC
have been designed to withstand theoretical
stresses and discover if composites could be
used to further improve the design.
Secondary aims have also been laid out which
are:
-Validate Finite Element Analysis model
-Produce finite element of the Bloodhound
SSC wheels
-Evaluate Bloodhound wheels for
optimization
Project Conclusion
Overall the FEA modelling has proved more
difficult than expect. It can be concluded that
the validation model shows close agreement
with one another, however further analysis
should be analysed for high speed tests, this
said there are still definitely possibilities that
a composite design can be used to further
improve the performance of the Bloodhound
SSC. Composites can offer great weight
savings which helps to reduce the inertial
forces and improve performance.