JEC COMPOSITES MAGAZINE - Issue #109 - November/December 2016 - 38

JEC ASlA awards

Development of a 14 seater sivil aircraft: 'SARAS',
integrating the fuselage bulkhead with the composite dome
CSIR-NAL has taken up the development of a 14-seater civil aircraft named
Saras. One of the challenges was to
design and develop the rear pressure
bulkhead as a part of the structural
weight reduction programme.
Weight savings and performance can
be maximized using co-curing technology, resulting in significant reductions
of fabrication cycle time, cost and
weight. Co-cured structures have fewer
fasteners, resulting in shorter assembly
cycle times and reduced sealing issues. The pressure bulkhead separates
the pressurized region of the fuselage
from the unpressurized region. Ideally,
a dome (shell) type of construction
is more efficient in transferring pressure loads by membrane action, which
is reacted as in-plane stresses in the

composite dome. Composites are best
utilized when deployed to resist inplane stresses. This property of the
shell makes it more economical than
a flat plate under the same loading
conditions. Composite domes have
been used for rear pressure bulkheads
in recent aircraft programmes such as
the A380, A350, B787, etc. The main
challenge was to integrate the fuselage
bulkhead with the composite dome.
This feature makes the composite rear
pressure bulkhead developed by CSIRNAL unique in the airframe industry.
The rear pressure bulkhead consists
of the fuselage frame, which is a ring
of 1.8m diameter having an I-section
co-cured with a dome-shaped skin.
Gussets are provided on either side of
web to connect longerons (stringers)
on either side of the bulkhead. The

EXVIEW: An innovative transparent composite
for trains with a new flame retardant concept
The project, which focuses on an innovative flame-retardant composite material, was conducted under
contract with Japan's Ministry of
Economy, Trade and Industry as part
of the Strategic Advance Technical
Assistance Business 2011 programme.
Developed by AIST, the Claist transparent clay film is 3 to 200μm thick
and possesses heat resistance and high
gas-barrier properties. It was already
used for various CFRP gas-barrier
tanks (hydrogen tanks for automobile
fuel and oxygen tanks for rocket fuel).
Inspired by this application, AIST conducted tests to apply these gas-barrier
properties for flame retardant performance. The composition combines the

AERONAUTICS
Winner: National Aerospace
Laboratories (India)

entire part is conceived such that all
three regions (dome, bulkhead and
gussets) are integrally made into one
part, taking the design/stress requirements along with manufacturing feasibility into consideration. The bulkhead is manufactured using a Hexcel
prepreg and an autoclave moulding
technique.

RAILWAY

flexible transparent clay film with advanced transparent epoxy composites.
First, the transparent epoxy composite
was moulded by infusion (8 layers of
glass fibre, clear epoxy resin and crystalline silica). Then it was cured in an
oven and the clay paste was coated
using a spray process. As a result, the
moulded transparent epoxy composite
possesses higher flame retardant properties than standard flame-retardant
composites and high enough strength
to be taken into consideration for train
lighting covers.

Winner: Miyagi Kasei Co., Ltd. ( Japan)
Partner: Research Institute for Chemical
Process Technology (AIST) (Japan)

This innovative technology of clay film
and transparent epoxy composites was
developed and adopted for the lighting
covers of the Japanese railways. The

partners received the authorization of
JRMA in 2014 and named this transparent epoxy composite EXVIEW®.

jec composites magazine / No109 November - December 2016

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #109 - November/December 2016