JEC COMPOSITES MAGAZINE - EXPERT’S DIGEST - ADDITIVE MANUFACTURING - 2020 - 107

EXPERT'S DIGEST
3D PRINTING
Fig. 3: True carbon
fibre 3D printing
combines material
performance with
optimized shapes

Fig. 4:
Structural
efficiency is a
" product " of
material performance and the
shapes that can
be fabricated

substructural elements and attachment
points that connect together, and it will
eventually transition to full free-form
generative design. In metal 3D printing,
the shape fully determines the path, but
with composites, both the shape and
fibre path need to be determined based
on performance requirements.
Next, the data logging capabilities of
the printer need to be correlated with
data from coupons and parts so that it
can effectively improve over time and
ensure consistency from part to part.
Today, these capabilities are built into
the machine so now it is only a matter of
generating enough data to develop and
train modelling algorithms. Finally, for
the most critical applications, the parts
will be micro-CT scanned for the highest possible performance and reliability
on every part delivered.
Advanced materials and
manufacturing landscape
3D printing of high-performance carbon
fibre is more than just bringing the
performance of carbon fibre to parts
currently made using machined metals.
Some parts or structures might work well
with a simple sheet or laminate without
additional stiffening structures that add
weight. However, since buckling resistance grows with the cube of thickness,
a shell structure will not always be the

lightest. How can this comparison be
abstracted to arbitrary part designs since
the exact performance metrics must be
narrowly defined? Structural efficiency
can simply be thought of as a generalized
performance metric derived from a
" product " of material performance and
the degree to which its shape is optimized.
The chart is based on shape alone, but
the full geometric optimization that
is possible for composites needs to
consider their anisotropy. From a purely
materials perspective, since 3D printing
enables design elements that do not have
the drawbacks of laminates, Mantis does
not necessarily have lower performance
on the X-axis than traditional composites for most parts. Since complex
3D-printed metal lattices and grids with
two force members do not need much
strength or stiffness in other directions,
their geometric efficiency is not necessarily better than what the company can
achieve with a simpler overall shape on
the Y-axis.
Aerospace 2.0
Historically, technological manufacturing shifts have been represented by leaps
in either the materials that can be manufactured or the shapes that are viable
to manufacture out of known materials.
What will the future of aerospace look

Expert's digest jec

like now that we have a substantial leap
forward on both fronts simultaneously?
Many people have bemoaned a lack
of innovation in the overall shape of
airplanes, and the increased financing
available for more efficient aircraft might
finally enable a more dramatic shift such
as a blended wing body plane. Since
commercial and manned military aviation have longer design cycles and more
regulations, these materials will most
likely be utilized in UAVs, satellites, and
race cars initially. Regardless of which
markets implement high performance
carbon fiber 3D printing first, one thing
is clear: anyone involved in aerospace or
motorsport structures has an exciting
future to look forward to.
More information:
www.mantiscomp.com
mchapiro@mantiscomp.com

As published in jec composites
magazine N°123 Aug./Sep. 2019

Focus
" The advantage of CFRP over
aluminium in terms of stiffness
trace (effective stiffness) would be
0.880/0.336 = 2.62. This is the penalty for the isotropy of aluminium
grids. " Stephen Tsai

composites magazine Additive Manufacturing

107
http://www.mantiscomp.com
JEC COMPOSITES MAGAZINE - EXPERT’S DIGEST - ADDITIVE MANUFACTURING - 2020

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