Laboratoire national de métrologie et d’essais
MEASUREMENT OF AEROSOLS
EMITTED FROM VARIOUS STRUCTURAL
COMPOSITE MATERIALS DURING
POST-CRASH FIRE EVENTS
M. Targosz1, C. Chivas-Joly1, C. Motzkus1, F. Gaie-Levrel1, S. Le Nevé2,
J. Gutierrez3, J.-M. Lopez-Cuesta4
1 Laboratoire national de métrologie et d'essais (LNE), 29, av. Roger Hennequin, 78197 Trappes, France
2 DGA-Aeronautical Systems, 47 rue Saint-Jean, 31130 Balma, France 3 DCNS Research, Indret, 44620 La Montagne, France
4 Ecole des Mines d’Alès (C2MA), 6 Avenue de Clavières, 30319 Alès Cedex, France
Corresponding author: [email protected]
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Content
1. DACOFEU Project
Philosophy
Samples
2. Experimental part
Experimental setup
Aerosol metrology
3. Results
Number concentration of particles
Mass size distribution
Microscopic analysis
4. Conclusions
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DACOFEU Project
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Introduction
DACOFEU Project
Research in aircraft fire safety
5 partners: LNE, DGA, INERIS,
DNCS Research and AIRBUS Helicopters
Aim & Objectives
Studies on the environmental effects caused by the dispersion
of fibers, particles and gases released during post-crash aircraft
fires from structural composites
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Production of aerosols and gases
during thermal degradation and combustion of
structural composites
Atmospheric dispersion
Thermal behaviour of composites
Philosophy of the DACOFEU Project
Evaluation of the particles
dispersion and their potential
environmental risk
Numerical modeling of combustion, production and
dispersion of gases and solids during a post-cras fire
A post-crash
aircraft fire
scenario
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Gases
Production
Focus on aerosols production
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Particles
7
Number
concentration
Size & mass
distribution
Presence of
fibers
Morphology &
chemistry
Time
evolution
Qualitative &
quantitaitve
analysis
Thermal behaviour of structural composites
Kind of
organic
matrix
Presence of
reinforcement
Loading of
nano-objects
Kind of nano-
objects
Orientation of
reinforcement
Structural composites
Number
concentration
Size & mass
distribution
Evolution
in time
Samples
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Structural composites
Aircraft and naval applications due to:
exeptional mechanical performance
chemical and electrical resistance
reduction of weight
reduction of fuel consumption
thermal resistance
Sourc
e:
FA
A
787 Dearamliner composite profile
50% of composites by weight
Sourc
e:
R.
You
nes
3D Woven composite material
Fibre Reinforced Polymers (FRP):
matrix – polymer-based resin
reinforcement – fibres: glass, carbon, aramid,
natural fibres
and/or additives: flame retardants, nano-objects
Tested materials
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Selection criteria of the aircraft and naval composites:
the shortest burnthrough time
and the highest level of damages
the highest yield of the total
smoke release
10 SCF - GDR Feux Workshop Incendies
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e:
DG
A/T
A
MAT 7 MAT 5 MAT 4 MAT 8
FAR 25-856-1, Appendix F, Part VII –
Test Method To Determine the Burnthrough
Resistance of Thermal/Acoustic Insulation Materials
Heat flux: 180 kW/m2
Composite
material
Time duration: 15 min
Kerosene burner
Samples
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Sample Organic matrix Nano-objects Reinforcement Fibers
orientation
MAT1 no Carbon fibers A no Interlaced
MAT2 Epoxy resin A 120 (100 wt.%) no no no
MAT3 Epoxy resin A 120 (50 wt.%) Carbon fibers A no Interlaced
MAT4 Epoxy resin B 120 (38 wt.%) Carbon fibers B no Interlaced
MAT5 Epoxy resin C 180 (29 wt.%) Carbon fibers C no Unidirectional
MAT6 Vinyl ester resin (35 wt.%) no Glass fibers no
MAT7 Vinyl ester resin (34 wt.%) Carbon nanotubes (1 wt.%) Glass fibers no
MAT8 Vinyl ester resin (30 wt.%) Carbon nanotubes (5 wt.%) Glass fibers no
Experimental part
Small scale
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APS
SEM analysis
Experimental setup
Data
Acquisition
System
Aerosol Neutralizer
(Source Kr85)
SMPS (DMA 3081
LongDMA
+ CPC3022)
Dekati Low
Pressure
Impactor
Heat flux:
75 kW/m2 with
standardized
ventilation rate;
Pilot spark;
Isokinetic
sampling
Exhaust duct
★Aerosol sampling Fire model
DLPI
Long DMA + CPC
2nd dilution
with filtred air
(20°C, cold stage)
★
Cone Calorimeter
Composite sample
SEM/AFM
(morphology
measurement)
4 configurations
DMS 500
DMS
1st dilution
with filtred air
(150°C, hot stage)
Aerodynamic Particle Sizer
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Aerosol metrology, equipement
Device Paremeter Range Flowrate Objectives
DLPI (Dekati Low
Pressure Impactor) Mass 30 nm – 10 µm 10 L/min
Granulometric mass distribution
Classification of aerosol populations and
masses
Diluteur Dekati L7 (hot
dilution) Flowrate Dilution factor 8 – 10 60L/min
Reduce the phenomena of coagulation and
saturation measuring equipment metrological
Diluteur Dekati VKL10
(cold dilution) Flowrate Dilution factor 10
5L/min (output)
need filtered air
Congulated and saturated aerosol metrology
measuring equipment in reduced temperature
CPC (Condensation
Particle Counter)
3775
3022
Concentration
(part/cm3)
Lower particle detection size
limit of:
4 nm – 107 part/cm3 max
7 nm – 107 part/cm3 max
0.3-1.5L/min Total concentration of submicron particles inf.
1mm
DMA L (longDMA) +
CPC 3775
DMA – set voltage +
CPC – evolution of
the concentration at
a given size
2 nm – 1 µm 0.3 ou 1L/min Evolution of the concentration at given size
(Delect mobility)
DMS 500
Evolution of the
particles
concentration at a
given size
5 nm – 1 µm 8.2 L/min Evolution of the concentration at given size
(Delect mobility)
APS 3021 Granulometric size
distribution 0.6 µm – 20 µm 5L/min Granulometric size distribution (Dae)
Overal measurement range: 2 nm – 20 µm
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Results
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Number concentration of particles, CPC Influence of carbon fiber reinforcement
0 50 100 150 200 250 300 3500.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Nu
mb
er
co
nc
en
tra
tio
n (
x 1
08 p
art
icle
s/c
m3)
Time (s)
AVG
AVG + SD
AVG - SD
0 50 100 150 200 250 300 3500.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Nu
mb
er
co
nc
en
tra
tio
n (
x 1
08 p
art
icle
s/c
m3)
Time (s)
AVG
AVG + SD
AVG - SD
MAT2, Epoxy resin A 120 alone MAT3, Epoxy resin A 120/carbon fibers A
3.3x108 part.cm-3
5.2x107 part.cm-3
Pressence of carbon fiber reinforcement in the epoxy resin results
in a significant reduction of particles emission
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0 50 100 150 200 250 300 3500.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Nu
mb
er
co
nc
en
tra
tio
n (
x 1
08 p
art
icle
s/c
m3)
Time (s)
AVG
AVG + SD
AVG - SD
Number concentration of particles, CPC Influence of reinforcement orientation
Orientation of CF modifies the thermal properties
materials with interlaced CF shows higher thermal stability and reduced
global particles emission
For materials with interlaced orientation of carbon fibers, only kinetics
of particles emission is modified due to different chemical composition
of the organic matrices
0 50 100 150 200 250 300 3500.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Nu
mb
er
co
nc
en
tra
tio
n (
x 1
08 p
art
icle
s/c
m3)
Time (s)
AVG
AVG + SD
AVG - SD
0 50 100 150 200 250 300 3500.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Nu
mb
er
co
nc
en
tra
tio
n (
x 1
08 p
art
icle
s/c
m3)
Time (s)
AVG
AVG + SD
AVG - SD
MAT3 MAT4 MAT5
Epoxy resin A 120/CF A interlaced Epoxy resin B 120/CF A interlaced Epoxy resin C 180/CF B unidirectional
5.2x107 part.cm-3
7.5x107 part.cm-3
9.5x107 part.cm-3
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0 50 100 150 200 250 300 350 4000.0
0.2
0.4
0.6
0.8
1.0
Nu
mb
er
co
nc
en
tra
tio
n (
x 1
08 p
art
icle
s/c
m3)
Time (s)
AVG
AVG + SD
AVG - SD
0 50 100 150 200 250 300 350 4000.0
0.2
0.4
0.6
0.8
1.0
Nu
mb
er
co
nc
en
tra
tio
n (
x 1
08 p
art
icle
s/c
m3)
Time (s)
AVG
AVG + SD
AVG - SD
0 50 100 150 200 250 300 350 4000.0
0.2
0.4
0.6
0.8
1.0
Nu
mb
er
co
nc
en
tra
tio
n (
x 1
08 p
art
icle
s/c
m3)
Time (s)
AVG
AVG + SD
AVG - SD
Number concentration of particles, CPC Influence of the CNT mass rate
MAT6 MAT7 MAT8
Vinyl ester resin/glass fibers Vinyl ester resin/CNT 1%/glass fibers Vinyl ester resin/CNT 5%/glass fibers
6.7x107 part.cm-3 6.1x107 part.cm-3 6.7x107 part.cm-3
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Presence of CNTs affects only the kinetics of particle emission
The particle production seems to be controlled by the CNTs loading
Better dispersion and lower pHRR is observed for 1 wt.% mass rate
Global number concentration of particles, CPC Influence of the organic matrix
Pure epoxy resin is predominant in particles generation
Vinyl ester resin based composites emit 25% more particles than epoxy resin based ones
Material with unidiractional carbon fibers produces 1/3 more particles compared
to composites with interlaced reinforcement
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Epoxy resin based composites Vinyl ester resin
based composites
Cumulative particle mass distribution, DLPI
0.01 0.1 1 100
20
40
60
80
100
120
Cu
mu
lati
ve
ma
ss
fra
cti
on
(%
)
Cut-off diameter (µm)
MAT2
MAT3
MAT4
MAT5
0.01 0.1 1 100
20
40
60
80
100
120
Cu
mu
lati
ve
ma
ss
fra
cti
on
(%
)
Cut-off diameter (µm)
MAT6
MAT7
MAT8
Epoxy resin/carbon fibers composites Vinyl ester resin/CNT composites
Independent on composite type, around 80% of global particles
emission is in submicronic range and only 10%, in the ultrafine range
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Microscopic analysis
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22
Effect on particle morphology and fiber presence?
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Samples Aerosol deposit Residue
Particles Particles & Fibers
Epoxy
resin/carbon
fibers
composites
Vinyl ester
resin/CNT/
glass fibers
composites Spectre 1
Spectre 1
Spectre 2
CNT
Spectre 2
Linear soot aggregates
Compacted soot aggreagates
Lack of fibers in aerosol deposit?
Need for more detailed microscopic analysis
Conclusions
Fire model of 75 kW/m2 seems to represent a post-crash aircraft fire conditions
Aerosol measurements
The smoke production is influenced by: chemical composition of organic matrix,
presence of carbon fibres or nanotubes and their mass percentage in the material,
and orientation of reinforcement
Incorporation of carbon fiber reinforcement into epoxy resin matrix reduces significantly
particles emission
Orientation of CF reinforcement modifies the thermal properties of composite materials
and the global particle emission
The particle emission seems to be controlled by the CNTs loading
Vinyl ester resin composites produce 25% more particles than epoxy resin based ones
The average total number concentration of particles obtained during tests is around 6.7x107
and 6.3x107 particles/cm3 for epoxy resin and vinyl ester resin based materials, respectively
80% of all produced particles are submicrometric, only 10% ultrafine
Morphological analysis shown presence of linear and compacted aggregates, made
of very elementary particles in order of 30-60 nm of aerodynamic diameter,
independent on the nature of tested materials
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Thank you for attention!
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