JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 30

microstructure

True 3D numerical
simulation technology

Fig. 3: Average concentration vs. rib thickness

Using fibre concentration
analysis to observe potential
surface defects
The part used in the following case is a
centered-gated disk with curved channels
placed throughout the part surface (see
Figure 4).
In Figure 5 (top), the areas where two
channels intersect are the areas with a
lower fibre concentration. This is due to
a higher shear rate in the channels that
makes it difficult for the polymer melt
to flow forward. Hence, a lower fibre
concentration value is observed in the
channel areas. Moreover, a similar fibre
concentration pattern is observed in the
reverse, flat face of the part that contains
no channel design (see Figure 5, bottom). Thus, it is crucial to attain a proper
fibre concentration analysis for product
design and optimization since the areas
with a lower fibre concentration are most
likely to incur surface defects.

Fig. 4: Centered-gated disk (top) with curved channels placed throughout the part surface (bottom)

To provide a more comprehensive
fibre analysis, Moldex3D rolled out the
first, and currently the only, simulation
capability in the CAE market for fibre
concentration prediction. Based on
the well-developed suspension balance
model and true 3D numerical simulation technology, the conservation
equation of particle volume fraction can
be computed by Moldex3D's powerful
simulation technology. The accuracy
of Moldex3D's simulation for fibre
concentration analysis is illustrated in
the following experiment. The geometry
of the model used in the experiment and
the simulation results for fibre concentration in the plate area are shown in Figure
6 (left). In the graph below (Figure
6, right), the accuracy of Moldex3D's
simulation is further validated by a comparison of the simulation results with the
experiment results of Vélez-García et al.
published in 2012. Both the simulation
results and the experiment results show
that the fibre concentration distribution
affects the melt viscosity, which directly
influences the filling velocity. The two
results shown here are consistent with
each other.

Conclusion
The enhanced simulation capability of
Moldex3D now includes a pioneering
technology for fibre concentration

Fig. 5: Fibre concentration analysis on both sides
of the modelled part

prediction. Users can benefit from a
comprehensive fibre microstructure
analysis with a full investigation of
fibre orientation, fibre length/breakage
and fibre concentration. This true 3D
numerical simulation technology not
only allows users to carry out simulation
tasks for their FRP product designs more
efficiently, but it also provides accurate,
in-time simulation results for product
design and optimization that ultimately contribute to a more productive
workflow, faster time-to-market, and
more importantly, more lightweight FRP
design concepts. n
More information:
www.moldex3d.com

Fig. 6: Geometry of the model used in the experiment (top, left), and simulation result for fibre concentration
in the plate area (bottom, left). As shown in the graph (right), the simulation results and experiment results
are consistent with each other

30 jec composites magazine / No105 June 2016

http://www.moldex3d.com

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #105 - June 2016