JEC COMPOSITES MAGAZINE - Issue #106 - July 2016 - 41

designed polybutadiene resin film. The
mesh-netting shell used to reinforce the
fuselage is made from extruded pellets
based on carbon fibre mixed with a
polypropylene sulphide (PPS) resin.
The design of a new configuration for
multifunctional skin layers will improve
productivity and the exploitation characteristics of rotor turbine blades. For
the mesh-netting shell, nanocomposites
combining polypropylene (PP) nanomaterials and multi-wall carbon nanotubes
(MWNTs) were produced by mixing
PP granules with a melt flow index of 12
g/10 min at 1900°C and 2 wt % PPg-MA (maleic anhydride). They were
produced using a co-rotating twin-screw
extruder at a barrel temperature of 1952100°C and a screw speed of 50 rpm.
The specifications of MWNTs in the
masterbatch are as follows: diameter,
9-11 nm; mean length of the nanotubes,
1.2 mm; and purity higher than 90%.
Ventilation was maintained during the
melt extrusion step to remove the air
trapped in the blends. The mechanical
behaviour of polypropylene/carbon nanotubes was studied in [10]. A structural
interpretation of the deformation and
fracture behaviour of polypropylene/
multi-walled carbon nanotube composites was published in [11].

Triaxial forces in
the mesh netting element
Triaxial stress forces are acting in the
mesh netting element. The normal
variable stresses are Xx, Yy, Zz, and shear
stresses Sxy, Szx, Szy will occur during a
shift in loading. Xx is a tensile stress that
depends on the engine's thrust power. Yy
and Zx are compression stresses created
by outside loading forces. (X), (Y) and

where P is the loading acting on the
fuselage mesh netting element, R is a
mid-section radius of the fuselage, and K
is the coefficient of anisotropy that will
be determined experimentally using test
samples.

Design of a multifunctional
hybrid fuselage
To design a multifunctional hybrid
fuselage, multifunctional materials were
created to protect the fuselage from lightning strikes while providing vibration
damping and sound absorption effects.
A lattice mesh netting reinforcement
and thermoplastic skins were used to
improve this package. The mesh-netting
shell structure project for the Boeing
fuselage is shown. The multifunctional

shell structure is represented.
The polyester top layer with Al2O3 nanoparticles is what protects the fuselage
from lightning and provides vibration
damping and sound absorption. The
MOCAP high-temperature polyester
tapes used are 152.4-mm wide, with a
roll length of 65.8 mm. Polyester tapes
are highly suitable for high-temperature
powder coating applications because
they can resist temperatures up to 218°C
for 1 hour [14].
Polyester formulations were developed
for the top layer.
The BCA A637 hardener is a highly
reactive aliphatic amine (Mannich
base hardener). Its advantages include
low-temperature cure and good chemical
resistance. The Dabco ®1030 catalyst was
used in the production of flexible moulded polyurethane foams. Health and safety
regulations along with the continued
push to eliminate VOC (volatile organic
compound) emissions were taken into
account.
The Dabco ®1030 catalyst was used only
when no blowing catalyst was needed.
The Dabco LK-443 surfactant is a unique
organic surfactant that can be used as a
replacement for silicon-based surfactants.
The Dabco DMDEE blowing agent is
an amine blowing catalyst used in rigid
foam sealant systems and in flexible
systems.

Tab. 1: Top layer polyester formulation

Ingredients

Formulation,
Manufacturer
%

Polyester polyol,
JEFFOL-A630

Huntsman Inc.

Hardener, BCA A637

Brenntag Inc.

Catalyst, Dabco ®1030

Air Product

Surfactant, DabcoLK443

0.1

Air Product

Blowing agent,
Dabco DMDEE

Air Product

Ethylene carbonate
solvent,
JEFSOL EC-50

Huntsman Inc.

Alternative ingredients
Dow Chemical polyols

When not using a blowing catalyst

Hydrofluorocarbonates FM-200 or
chlorofluorocarbonates Laprolate
803, fluoro-solvent, fire suppressor
HFC-134a

No106 July 2016 / jec

Feature Aeronautics

Instead of the metal foil inserted in the
CFRP package for lightning protection
of the aircraft structure, aluminium nanoparticles (Al2O3) were inserted in unsaturated polyester. The average diameter of
the nanoparticles was 15 nm. Fracture
toughness was increased by almost 100%
[12]. Young's modulus was compared
with a classical theoretical modulus [13].

(Z) are the strengths in the x, y and z directions. The coefficient of anisotropy K
expresses the relation between strength
in the x, y and z directions and in the
diagonal directions x45, y45, z45. In the
formula used to determine the mesh
netting size, (X45), (Y45) and (Z45)
designate the strengths in these directions. So, the size of the mesh netting
element is AxB, expressed as:

composites magazine 41

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #106 - July 2016