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Fig. 5.11 Load and boundary conditions in the case of the curved layer FDM part
5.6 Results and discussion
A lot of data is generated from the finite element analysis of the stress fields of the
two parts in terms of displacements and various stress components. However, the
finite element results are mainly considered to compare the maximum displacement
values with the maximum allowable displacement of the material as generated by the
tensile test conducted on the raw material and presented in the load-displacement
diagram of Fig. 5.6. The reason for this is a lack of experimental data on other
parameters. The distribution of the stress components will also be used, but mainly
to assess the stress patterns generated in different material deposition schemes.
Each of the model is analysed for a time dependent variation of the applied loads.
Fig. 5.12 presents a series of screen shots showing the gradual increase in the
applied load and the corresponding variation in the displacement. There is a peculiar
problem observed in the case of the flat layer FDM model, the applied load is
concentrated at a few points, in a very narrow zone. The component assumes a
completely distorted shape, and to reach the target load of 400-500 N overall, it was
necessary to increase the total of nodal loads beyond 900 N. The model was tested
a number of times, with all load and boundary conditions repeatedly checked, but the
end result was the same. It was finally concluded that the relatively weak interaction
between the flat layers, in particular at regions, where the part bends into a curved
shape from the flat portions leads to an early failure and the strands are almost
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