The behavior of materials with a complex structure strongly depends on the
spatial arrangement of their components. In mechanical parts of short glass
fibre reinforced polymer (SFRP) obtained by injection moulding, processing
conditions produce complex orientation patterns that in°uence the mechanical
properties of the component. For example, different fatigue (i.e. failure caused
by cyclically repeated loads) behaviors can be observed when short fibre rein-
forced polyamide notched specimens of same geometry are injection moulded
through gates whose position is varied. This effect appears to be due to
the different fibre orientation patterns obtained and it can be interpreted
in terms of different local material properties related to fibre orientation and
distribution. Traditional, destructive, approaches to fibre pattern identification
are affected by severe limitations. Recently, a novel technique based on micro-
tomography 3D reconstruction of the fibre structure has been introduced for
quantification of fibre pattern.
