Laboratoire national de métrologie et d’essaisdocs.gdrfeux.univ-lorraine.fr/Corte2/LNE01.pdf9 SCF - GDR Feux Workshop Incendies 25-27 June 2014 Structural composites Aircraft and

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]

SCF - GDR Feux Workshop Incendies

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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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9 SCF - GDR Feux Workshop Incendies

25-27 June 2014

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

25-27 June 2014 Sourc

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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Documents

Laboratoire national de métrologie et d’essaisdocs.gdrfeux.univ-lorraine.fr/Corte2/LNE01.pdf9 SCF - GDR Feux Workshop Incendies 25-27 June 2014 Structural composites Aircraft and