JEC COMPOSITES MAGAZINE - Issue #87 - March 2014 Special JEC Europe - 57

Fig. 3: 'Exhaust' braiding process in Braidsim

for crash performance. It can be improved
by using two fibre materials instead of one,
creating a 'hybrid'. In the braiding process,
this is easily accomplished by putting the
first and second fibre material on the odd
and even spools within a yarn group, respectively, leading to an alternating pattern
and a highly homogeneous and controlled
distribution. The yarn linear densities
need not be the same and can be tailored
to fit the chosen compromise of various
structural requirements.

Braidsim
When considering braiding as a manufacturing method, structural
optimization software can
be used to generate an appropriate fibre distribution,
given the geometry and
loads. However, the question remains whether the
resulting distribution can
be obtained with a braiding
machine. For a non-expert,
this question cannot be
answered by intuition. The
Braidsim software (Fig. 3
and Fig. 4) developed at
the University of Twente
(UT) was designed to assist engineers by running a
process simulation in just a
few minutes. These simulations can be embedded in
the virtual process chain to
generate optimized braiding
machine control data and
files for downstream analysis
such as resin infusion and

structural performance. Engineers can
use simulation to explore a wide variety
of 'what-if' scenarios, including different
product geometries, fibre architectures
and machine configurations. Potential
production problems can be detected in
advance. Examples are yarns that slip off
the mandrel during production despite the
interlacement or a braid that 'jams' before
it gets in contact with the mandrel because
the mandrel diameter is locally too small
for the given number of yarns. Other
undesired effects can be local mandrel regions that are not covered by yarns. These
effects can be visualized by Braidsim to
allow adjustment of the design, aiming for
a physical product that is first-time-right.
Fig. 5 shows the validation of the software
at Eurocarbon, the industrial partner of the
UT, which is necessary to identify modelling improvements and to set priorities
for further development of the software
and hardware. Fig. 6 shows the current
features and limitations of Braidsim.
Braiding-related knowledge used to be
mainly available at braiding manufacturers.
Braidsim now enables a wide audience to

Fig. 5: 'Nozzle' Braidsim model (upper) and
experiment (lower) - Courtesy Eurocarbon BV

become familiar with braiding, without
the need to commission capital-intensive
equipment. Hopefully this will encourage
a faster spread and adoption of braiding
technology for the benefit of all. n
More information:
www.braidsim.com

Fig. 6: Braidsim features
- seems stretched out of
proportion in height direction,
changing the circle to an oval

Fig. 4: 'Exhaust' result in Braidsim

No87 March 2014 /

jec composites magazine 57
http://www.braidsim.com
JEC COMPOSITES MAGAZINE - Issue #87 - March 2014 Special JEC Europe

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #87 - March 2014 Special JEC Europe
