JEC COMPOSITES MAGAZINE - Issue #104 - April/May 2016 - 30

awards

Compliant morphing technology and software for product designers of the future
By using compliant design expertise and
methods, FlexSys was able to design a
single-piece wiper arm and blade that
costs less and both outlasts and outperforms traditional metal assemblies. A
composite thermoplastic of 30%-glassfilled PBT was determined to have the
required properties and characteristics
to meet the demands and provide the
necessary strength/stiffness ratio. The
single-piece moulded design eliminates 11
parts along with the associated assembly,
weighs half as much, and costs only 1/3 as
much as the legacy design.
Unlike the traditional hinged blade, this
wiper provides constant spring pressure to
the blade through each of its arms. However, the difficulty in development was
that current 3D modelling programs were
not up to the task, as they design using
rigid members and linkages. In compliant
design, the elasticity of materials must be

embraced and used to create motion. To
surmount this obstacle, FlexSys is developing unique software called FlexWorks,
with the help of a grant from the National
Science Foundation. This software allows
the input of desired motions and magnitudes, and will run through thousands
of iterations to find one to most closely
fit the given criteria. It considers the
maximum stress/strain capability of
the material in each iteration so as not
to exceed it. The output provides the
required thickness variation throughout
each bending member. It will also show
the new compliant mechanism in motion,
bending, and displaying a stress analysis.
The final design can be changed in the edit
mode and re-evaluated, then saved in a
file to 3D print or import to Solidworks,
Ansys, etc. FlexSys believes the software
could eventually become a module
available in 3D modelling programs. The

Green PPS leading edge cover made from
recycled thermoplastic composite materials
The innovation is a green PPS leading
edge cover made from recycled thermoplastic composite materials. The
project encompasses the recycling of scrap
material generated during the manufacture of thermoplastic composite parts.
For example, scrap is produced when
manufacturing a rudder, elevator or wing
part using thermoplastic prepregs and
an autoclave process. The scrap can be
re-used by cutting the material to flakes
of +/- 10 mm × 10 mm and subsequently
applying a compression moulding process
to form a complex structural part. In a
closed recycling process, this part can be
used in the same structure as for which
the scrap was generated, such as (for
example) an edge cover in the aforementioned rudder, as is demonstrated with
the current innovation. The demonstrator
was built using experimentally validated

design rules, taking into account the
complicated flow behaviour of the flake
material and the stochastic nature of the
mechanical properties.
The use of thermoplastic composites
reduces manufacturing costs and part
weight. The recycling potential of thermoplastic composites is clearly demonstrated with this innovation, which is an
important step in the cost optimization of
composite design and manufacture.
The market potential is very large in
areas where thermoplastic composites
are already used. As demonstrated,
the prepreg scrap generated during
the production of large thermoplastic
composite structures can be well used for
(small) complicated parts attached to that
structure. Moreover, the use of thermoplastic flakes (moulding compound)
was demonstrated in other projects as a

30 jec composites magazine / No104 April - May 2016

Design

Winner: FlexSys Inc. (USA)

first ever public view and alpha release of
the software will be available in the JEC
Atlanta demo zone.
The advancement of composite injection
moulding materials will fuel the future
of compliant structures. Additives such
as carbon fibres and nanotechnologies
can increase the strength/flexibility ratio,
allowing for higher load applications
with greater fatigue-free travel. More
compliant design concepts can be seen
in the demo zone, including applications
in the automotive, medical, robotics and
prosthetics fields.

Aeronautics
Winner: ThermoPlastic Composites
Research Center (The Netherlands)
Partners: Fokker Aerostructures B.V.
(The Netherlands), TenCate Advanced
Composites B.V. (The Netherlands)

promising material for structural, geometrically complex structures such as aircraft
window frames. This innovation provides
theoretical tools in the form of processing
and design guidelines to further enhance
the application of thermoplastic moulding
compounds.

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #104 - April/May 2016