Abstract
M.Ing. (Mechanical Engineering)
As part of the effort in reducing the weight of a lightweight solar powered vehicle, alternative
options for lighter construction material for the wheel should be investigated. The aim of this
dissertation is to evaluate the structural integrity of a carbon fiber reinforced polymer wheel
by numerical analysis and verify the results through limited structural integrity tests on
manufactured test specimens.
A framework for the process of this investigation is drafted and verified during the course of
this analysis. This framework can be utilised for similar analysis’s subject to a few limiting
factors identified in the scope of the project mainly the anisotropic material properties and
static failure modes for the part. These limitations form part of the recommendations for
further study in order to expand on the flexibility of the framework for multiple scenarios
involving carbon fiber reinforced polymer parts.
Following the framework, a CAD model of the part was designed based on the part
requirements and manufacturing process for such part. Tensile test samples were
manufactured and tested in order to attain the material properties of the CFRP which would
then be utilised to generate a custom anisotropic material in the FEA software. The
simulations were setup and run in two different test variations based on common failures seen
in commercially available CFRP wheels. This provided maximum static loadings and
deformation which model could withstand.
From the CAD model a two piece aluminium mould was CNC machined in order to provide
an accurate manufacturing process which would allow the layup of test specimens which
accurately represent the CAD model. Eight test specimens were manufactured, providing 4
samples per each of the 2 test variations. The samples were setup for the structural integrity
testing and tested till failure with the load and deformation being measured
The results from the structural testing and FEA simulations were compared, with FEA
simulations measuring a maximum load possible on the model up to 20% greater than that of
the test specimens and deformation up to a maximum of 25% greater. Accuracy limitations
are attributed to imperfections in the manufactured test specimens. With these accuracies
taken into account the simulations can be adjusted to allow for the improving of the overall
design prior to manufacturing prototypes to be tested. Potential over engineering of the
samples based on increasing the structural integrity of the model using the 20% loading
accuracy and 25% deformation accuracy will have little impact on the final design.