Title: COMPOSITE MATERIAL FIRE FIGHTING RESEARCH
1COMPOSITE MATERIAL FIRE FIGHTING RESEARCH
- ARFF Working Group
- October 8, 2010
- Phoenix, AZ
- Presented by
- Keith Bagot
- Airport Safety Specialist
- Airport Safety Technology RD Section
- John Hode
- ARFF Research Specialist
- SRA International, Inc.
2Presentation Outline
- FAA Research Program Overview
- Composite Aircraft Skin Penetration Testing
- Composite Material Cutting Apparatus
- Development of Composite Material Live Fire Test
Protocol
3FAA Research Program Overview
FAA HQ, Washington, DC
Tyndall AFB, Panama City, FL
FAA Technical Center, Atlantic City, NJ
4FAA Research Program Overview
5FAA Research Program Overview
- Program Breakdown
- ARFF Technologies
- Operation of New Large Aircraft (NLA)
- Advanced Composite Material Fire Fighting
-
6FAA Research Program Overview
- Past Projects
- High Reach Extendable Turrets
- Aircraft Skin Penetrating Devices
- High Flow Multi-Position Bumper Turrets
- ARFF Vehicle Suspension Enhancements
- Drivers Enhanced Vision Systems
- Small Airport Fire Fighting Systems
- Halon Replacement Agent Evaluations
7Advanced Composite Material Fire Fighting
- Expanded Use of Composites
- Increased use of composites in commercial
aviation has been well established - 12 in the B-777 (Maiden flight 1994)
- 25 in the A380 (Maiden flight 2005)
- 50 in both B-787 A350 (Scheduled)
- A380, B-787 A350 are the first to use
composites in pressurized fuselage skin
8Advanced Composite Material Fire Fighting
- Research Areas
- Identify effective extinguishing agents.
- Identify effective extinguishing methods.
- Determine quantities of agent required.
- Identify hazards associated airborne composite
fibers.
9Composite Aircraft Skin Penetration Testing
10Composite Aircraft Skin Penetration Testing
- 3 Types of Piercing Technologies
11Composite Aircraft Skin Penetration Testing
- Objectives
- Provide guidance to ARFF departments to deal with
the advanced materials used on next generation
aircraft. - Determine the force needed to penetrate fuselage
sections comprised of composites and compare to
that of aluminum skins. - If required forces are greater, will that
additional force have a detrimental effect on
ARFF equipment. - Determine range of offset angles that will be
possible when penetrating composites and compare
to that of aluminum skins.
12Composite Aircraft Skin Penetration Testing
- Phase 1 Small-Scale Laboratory Characterization
of Material Penetration for Aluminum, GLARE and
CRFP (Drexel University) - Phase 2 Full-Scale Test using the Penetration
Aircraft Skin Trainer (PAST) Device (FAA-TC) - Phase 3 Full-Scale Test Using NLA Mock-Up Fire
Test Facility (Tyndall Air Force Base)
13Composite Aircraft Skin Penetration Testing
- Test Matrix Developed
- Three Materials
- Aluminum (Baseline)
- GLARE
- CFRP
- Three Thickness
- Three Loading Rates
- Two Angles of Penetration
- Three Repetitions
14Composite Aircraft Skin Penetration Testing
15Composite Aircraft Skin Penetration Testing
16Composite Aircraft Skin Penetration Testing
17(No Transcript)
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19ASPN Penetration/Retraction Process
Material deformation tip region penetration
Conical region penetration
Cylindrical region penetration
Retraction
20ASPN Penetration and Retraction Forces
NP
PP
PR
NR
Constant force is required to perforate aluminum
panels after initial penetration Increasing force
is required to perforate CFRP and GLARE panels
after initial penetration
21Maximum Plate Penetration (PP) and Plate
Retraction (PR ) Loads at 0.001 and 0.1 in/s
- For Aluminum panels Retraction load is higher
than penetration load, caused by petals gripping
the panel upon retraction (due to elastic
recovery) - For GLARE and CFRP panels Penetration load is
higher than retraction load - petals remain
deformed (due to local damage of composite plies)
22Maximum Nozzle Penetration (NP) and Nozzle
Retraction (NR ) Loads at 0.001 and 0.1 in/s
- For Aluminum panels Retraction load is higher
than penetration load, caused by petals gripping
the panel upon retraction (due to elastic
recovery) - For GLARE and CFRP panels Penetration load is
higher than retraction load - petals remain
deformed (due to local damage of composite plies)
23Petals Formation
GLARE (Normal Penetration)
Aluminum (Normal Penetration)
CRF (Normal Penetration)
Aluminum (Oblique Penetration)
24Composite Material Cutting Apparatus
25Composite Material Cutting Apparatus
- Purpose
- Increased use of composite materials on aircraft
- Limited data available on cutting performance of
current fire fighting tools on composite
materials - Aim to establish a reproducible and scientific
test method for assessing the effectiveness of
fire service rescue saws and blades on aircraft
skin materials
26Composite Material Cutting Apparatus
- Objectives
- Create an objective test method by eliminating
the human aspect of testing - Design a test apparatus that facilitates testing
of 4X2 panels of aluminum, GLARE, and CFRP - Measure
- Blade Wear
- Blade Temperature
- Blade Speed
- Plunge Force
- Axial Cut Force
- Cut Speed
- Utilize computer software and data acquisition
devices to monitor and log data in real time
27Composite Material Cutting Apparatus
Design Progression
28Composite Material Cutting Apparatus
29Composite Material Cutting Apparatus
30Composite Material Cutting Apparatus
31Composite Material Cutting Apparatus
32Development of a Composite Material Fire Test
Protocol
33Development of a Composite Material Fire Test
Protocol
What we knew before this testing
ALUMINUM CARBON/EPOXY GLARE
Norm for ARFF Unfamiliar to ARFF Unfamiliar to ARFF
Melts at 660C (1220F) Resin ignites at 400C (752F) Outer AL melts, glass layers char
Burn-through in 60 seconds Resists burn-through more than 5 minutes Resists burn-through over 5 minutes
Readily dissipates heat Holds heat May hold heat
Current Aircraft B787 A350 2 Sections of A380 skin
34FedEx DC10-10F, Memphis, TN 18 December
2003 Aluminum skinned cargo flight
Traditionally, the focus is on extinguishing the
external fuel fire, not the fuselage.
35Representative IncidentAir China at Japan Naha
Airport, August 19, 2007
4 minutes total video 3 minutes tail
collapses ARFF arrives just after tail collapse
36Development of a Composite Material Fire Test
Protocol
- External Fire Control Defined
- Extinguishment of the body of external fire
- Our question Will the composite skin continue to
burn after the pool fire is extinguished, thereby
requiring the fire service to need more
extinguishing agent in the initial attack? - Cooling of the composite skin to below 300F
- Our question How fast does the composite skin
cool on its own and how much water and foam is
needed to cool it faster? - 300F is recommended in the IFSTA ARFF textbook
and by Air Force T.O. 00-105E-9. (Same report
used in both) - Aircraft fuels all have auto ignition
temperatures above 410F. This allows for some
level of a safety factor.
37Creation of a Test Method
- First objective
- Determine if self-sustained combustion or
smoldering will occur. - Determine the time to naturally cool below 300F
(150C)
- Second objective
- Determine how much fire agent is needed to
extinguish visible fire and cool the material
sufficiently to prevent re-ignition.
- Exposure times of Initial tests
- 10, 5, 3, 2, 1 minutes
- FAR Part 139 requires first due ARFF to arrive in
3 minutes. - Actual response times can be longer or shorter.
38Initial Test Set-up
Color Video
FLIR
Color Video at 45 Front view
39Initial Test Set-up
40Test 10 Video
41Initial Results
- Longer exposure times inflicted heavy damage on
the panels. - Longer exposures burned out much of the resin.
- Backside has hard crunchy feel.
- Edges however, seem to have most of the resin
intact. Edge area matched 1 inch overlap of
Kaowool.
Test 6, 10 minute exposure
Edge View
Front (fire side)
Back (non-fire side)
42Panel Temperatures
43Other Test Configurations
- Tests 22 and 23
- The panel was cut into 4 pieces and stacked with
¾ inch (76.2mm) spaces between. - Thermocouples placed on top surface of each
layer. - Exposure time 1 minute.
44Other Test Configurations cont.
- This configuration not representative of an
intact fuselage as in the China Air fire. - Measured temperatures in the vicinity of 1750F
(962C). - Wind (in Test 22) caused smoldering to last 52
seconds longer.
45Initial Findings
- Post-exposure flaming reduces quickly without
heat source - Off-gassing causes pressurization inside the
panel causing swelling - Internal off-gassing can suddenly and rapidly
escape - Off-gas/smoke is flammable
- Longer exposures burn away more resin binder
- Smoldering can occur
- Smoldering areas are hot enough to cause
re-ignition - Smoldering temperatures can be near that of fuel
fires - Presence of smoke requires additional cooling
- Insulated areas cooled much more slowly than
uninsulated areas
46Further Development of Fire Test Protocol
- Data from first series of tests was used to
further modify the protocol development. - For example, larger panels and different heat
sources were utilized in this round of
development. - Larger test panels will be needed for the agent
application portion of the protocol. - Lab scale testing conducted to identify burn
characteristics. - Testing was conducted by Hughes Associates Inc.
(HAI).
47Further Development of Fire Test Protocol
- Lab scale tests
- ASTM E1354 Cone Calorimeter
- Data to support exterior fuselage flame
propagation/spread modeling - ASTM E1321 Lateral Flame Spread Testing (Lateral
flame spread) - Thermal Decomposition Apparatus (TDA)
- Thermal Gravimetric Analysis (TGA)
- Differential Scanning Calorimetry (DSC)
- Pyrolysis Gas Chromatograph/Mass Spectroscopy
(PY-GC/MS)
48Further Development of Fire Test Protocol
- Secondary test configuration (agent application
to be tested at this scale) - Three different heat sources evaluated
- Propane fired area burner (2 sizes)
- Propane torch
- Radiant heater
- Sample panels are 4 feet wide by 6 feet tall
- Protection added to test rig to avoid edge
effects. - A representative backside insulation was used in
several tests.
49Further Development of Fire Test Protocol
- 12 total tests conducted
- 9 with OSB
- 1 uninsulated
- 8 insulated
- 3 with CFRP
- 1 uninsulated
- 2 insulated
50OSB Exposed to Large Area Burnerwith Insulation
Backing
Large Area Burner On
Burner Off 30 seconds
Burner Off 0 seconds
Burner Off 100 seconds
Burner Off 60 seconds
51CFRP Exposed to Torch Burner with Insulation
Backing
Torch Ignition
1 minute after ignition
1.5 minutes after ignition
15 seconds after torches out
4 minutes after ignition Torches Out
2.5 minutes after ignition
52Findings
- Ignition occurred quickly into exposure
- Vertical/Lateral flame spread only occurred
during exposure - Post-exposure flaming reduced quickly without
heat source - Jets of internal off-gassing escaped near heat
source from the backside - Generally, results are consistent with small
scale data
53Test Conclusions
- OSB vs. CFRP
- Both materials burn and spread flame when exposed
to large fire - Heat release rates and ignition times similar
- The thicker OSB contributed to longer burning
- Large Scale Implications
- OSB can be used as a surrogate for CFRP in
preliminary large scale tests - Flaming and combustion does not appear to
continue after exposure is removed - Since there was no or very little post exposure
combustion, no suppression tests performed as
planned - Minimal agent for suppression of intact aircraft?
54Qualifiers to Results
- Need to check GLARE
- No significant surface burning differences
anticipated ( may be better than CFRP) - Verify /check CFRP for thicker areas (longer
potential burning duration) - Evaluate edges/separations
- Wing control surfaces
- Engine nacelle
- Stiffeners
- Post crash debris scenario
- Can a well established fire develop in a
post-crash environment?
EXAMPLE COMPLEX GEOMETRY FIRE TEST SETUP FOR CFRP
FLAMMABILITY EVALUATION.
55Summary
- Carbon fiber composite has not shown flame spread
and quickly self-extinguish in the absence of an
exposing fire. - Carbon fiber can achieve very high temperatures
depending on configuration through radiation. - Initial lab tests and fire tests show similar
results and are consistent. - Smoke should be used as an indicator of hot spots
that must be further cooled. - OSB can be used for large scale testing to
establish parameters to save very expensive
carbon fiber for data collection.
56Questions or Comments?
- FAA Technical Center
- Airport Technology RD Team
- AJP-6311, Building 296
- Atlantic City International Airport, NJ 08405
- Keith.Bagot_at_faa.gov 609-485-6383
- John_Hode_at_sra.com 609-601-6800 x207
- www.airporttech.tc.faa.gov
- www.faa.gov/airports/airport_safety/aircraft_rescu
e_fire_fighting/index.cfm