JEC COMPOSITES MAGAZINE - Issue #106 - July 2016 - 25

blocks: automatic UD (unidirectional) stiffening ply drop-off with a special machine
developed by Nimitech Innovation and
fully-automated non-destructive testing
(tomography).

Infusion, a new OoA solution

Fig. 3: Infused fuselage panel demonstrator

fibre deviations, gap & lap positioning and
ply drop-off locations (many reinforced
areas). Based on this first development
experience, the company's research &
development department initiated an R&T
project to develop an integrated smart
connection between the different numerical tools used by the manufacturing and
engineering teams to automatize the optimization process and reduce the number of
development loops (Figure 1).
This smart connection enables Stelia Aerospace to develop a new composite sizing
strategy based on the actual localization,
fibre orientation and gaps & laps of the
manufactured part. These properties will be
applied to the DFEM model to assess the
part's stiffness accurately and integrate local
knock-down factors (KDF) instead of the
currently used global KDF.

To improve the competitiveness of its series
programmes, Stelia Aerospace is developing
highly targeted R&T projects to replace
titanium parts with composite parts.
This concerns primary structures such as
door framings on nose section zones or
secondary structures.
To this end, the company launched the
Rectangular Composite Box project
(Figure 2), which aims to replace a titanium
box assembled from several parts with
a one-piece composite design. To date,
several full-scale prototypes have been used
to validate the TRL4, enabling this project
to contribute several innovative building

The first technical-economic studies
conducted show the relevance of this process, which could significantly reduce the
industrial investments in a new programme.
However, the company still has to work
on the technological building blocks for
ancillary products (automation and cost of
bagging) and on the manufacture of cores
for stiffeners.
In addition to this progress, Hexcel Composites and Stelia Aerospace are currently
conducting tests on the automatic lightning
strike protection drop-off on dry preforms
(the first developments were initiated by
Hexcel Composites). The integration of this
type of function is essential to ensure the
same level of performance as the current
fuselage panels. The dry fibre coupled with
infusion offer the advantage of a lower total
cost of use by industrial companies than
prepreg technology, as with thermoplastic materials: non-refrigerated transport,
storage at room temperature, no pollution
of drop-off machines, no workshop life
cycle, etc.

R&T partners
Stelia Aerospace relies on a strong network
of 200 subcontractors, around twenty partners and its (current and future) customers
to prepare its future product range: aerostructures, systems and cabin interiors.

With a turnover of 2.2 billion dollars in
2015 and more than 6,100 employees
worldwide, Stelia Aerospace supports
major aeronautical players such as Airbus, ATR, Boeing, Bombardier, Embraer
or Dassault. The company is present in
France, in Méaulte, Mérignac, Rochefort,
Saint-Nazaire, Salaunes and Toulouse,
and worldwide, in Canada, Morocco and
Tunisia.

All of the metal and composite assembly
technological networks are represented, including material suppliers such as
Constellium and Hexcel Composites, tool
suppliers such as Composes and Loiretech,
composite part suppliers such as Duqueine
and Corse Composite Aeronautique, as well
as Coriolis and Dufieux for the supply of
special machines.
Stelia Aerospace also relies on state research
and testing platforms such as Compositadour, technological research institutes IRT
Jules Verne and IRT Saint-Exupéry, and the
DGA-TA (French Military Procurement
Agency - Aeronautical Technology), as well
as private platforms such as the Institut de
Soudure (French Welding Institute) and
Airbus Group Innovation. For low TRL,
Stelia Aerospace also calls on the academic
world: Institut Clément ADER, Ecole Centrale de Nantes or Arts & Métiers. Exploratory research projects are also conducted
with accredited partners such as Onera, for
a project on the topological optimisation
of anisotropic composite structures. On a
worldwide scale, the company is beginning
to join research networks in Europe and
Canada, where it is developing projects with
the NRC (National Research Council Canada) on mechanical machining development.
Stelia Aerospace has fully integrated its
internal research process into its EN9100
certification in order to manage all of these
R&T projects, and has set up its own technology readiness procedure. It goes without
saying that its partners and subcontractors
are associated with this. n

No106 July 2016 / jec

More information:
www.stelia-aerospace.com

Feature Aeronautics

From titanium design
to composite design

In partnership with Hexcel Composites,
Stelia Aerospace is currently working on the
industrial feasibility of large fuselage panels
using dry fibre/infusion AFP technology
and OoA (out of autoclave) polymerization
(Figure 3). Several small-scale demonstrators were used to highlight the good
material integrity obtained for a primary
structure produced with this technology
(JEC Awards 2015 received by Hexcel
Composites, Coriolis and Stelia Aerospace
in March 2015, material used: Hitape®).

Focus

composites magazine 25
http://www.stelia-aerospace.com
Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #106 - July 2016
