ensc 22_final presentation_phases_1&2
TRANSCRIPT
ENSC 22 FIRE RESISTANT SURFACES & SPOILER DESIGN
Team: Chrystal Camacho, Andrew Justice, Matt Knowles, Mike Phillips
Advisor: Andrew Johnston
BACKGROUND • Phase 1: Enhanced Fire Protection For Metal-Bonded Surfaces
Baseline skin to the rear of the nacelle is aluminum, with an E-glass skin.
Per FAR 25.867: Skin w/in 2 nacelle diameters to the rear of the nacelle must withstand 2000 degree Fahrenheit flame burn test for 5 minutes at a distance of 4 inches from the burner exhaust.
We must find a suitable replacement for the baseline skin that can pass the Federal Aviation Regulation (FAR) 25.867 test
• Phase 2: Design Optimization of Spoilers
We must analyze different materials and manufacturing methods
Goal: reduce weight and cost
Current process: metal-bonded assemblies
PHASE 1
PHASE 1 BACKGROUND FAR FAR 25.867 states:
Ҥ 25.867 Fire protection: other components.
( a) Surfaces to the rear of the nacelles, within one nacelle diameter of the nacelle centerline, must be at least fire-resistant.
(b) Paragraph (a) of this section does not apply to tail surfaces to the rear of the nacelles that could not be readily affected by heat, flames, or sparks coming from a designated fire zone or engine compartment of any nacelle.”
PHASE 1 RESEARCH HISTORY INVALID SOLUTIONS
• PyroSic / PyroKarb by Pyromeral Systems
• K-Shield Felt by Hexcel Corp.
• Nextel 312 Ceramic Fiber Fabric by 3M
• Ceramic Spray Coating by Jet-Hot
SOLUTION: SANDWICH PANEL
3 Plies of S2 Style 6781 Fiberglass w/ RM-3004 BMI Prepreg
1 Ply of RM-3011 BMI Film Adhesive
Front Aluminum Face Plate
Aluminum
Honeycomb Core
Back Aluminum Face Plate
SOLUTION: S-2 FIBERGLASS STYLE 6781 • Softening Temperature is 1933°F
• High strength capacity
• Density = 0.0889 lb/in3
• Renegade Materials is a vendor
Company performs custom work
• Similar to Boeing’s current fiberglass solution to FAR 25.867
Implementation of manufacturing
change would be small
Renegade Materials HQ in Miamisburg, OH
SOLUTION: BMI Prepreg • Renegade Material’s RM-3004 BMI Pre-Impregnation( Prepreg)
Out of Autoclave (OOA ) Process
• Glass Transition Temp = 530°F w/ Post Cure, 484°F w/out Post Cure
Higher temp rating than epoxy currently in use
• Has been proven to pass the FAR 2000°F burn test
Test conducted by University of Cincinnati in conjunction w/ Renegade and GE
BMI used on carbon fiber panel
SOLUTION: MANUFACTURING
• Janicki Industries
Students perform manufacturing of panel
Impregnate S2-Style 6781 Fiberglass with
RM-3004 BMI Prepreg
Cure by Out of Autoclave
(OOA) process
Post-Manufactured skin thickness of
0.024± 0.005-in (total thickness of all 3 plies
+ adhesive film )
will be close to that used by Boeing (0.02 in)
REMOVING ORIGINAL E-GLASS FROM SUPPLIED COUPONS
• Original fiberglass skin had to be removed in order to be replaced
• Methods:
Paint stripper
Hydrochloric acid
Sulfuric acid
Nitric Acid
Milling
Filing
Sand blasting
Electric sanding
Ineffective
Effective, but not
time efficient
Best method
Effective & time
efficient
Scratches
from filing
Sand blasted
area
ALODINING THE COUPONS Before Alodining
After Alodining
During Alodining
CUTTING THE BMI PREPREGED FIBERGLASS & FILM ADHESIVE
RM-3011 BMI film adhesive applied using freeze spray
S2 fiberglass pre-impregnated with RM-3004 BMI
LAY-UP PROCESS
OVEN CURE PROCESS
Renegade Materials
Recommended cure
Janicki Industries
Recommended cure
ENSC 22
Performed cure
16 hours – Room
Temperature Debulk
8 hours – Room
Temperature Debulk
8 hours
2 hours @ 260 ⁰F 9 hours 2 hours
2 hours @ 290 ⁰F 2 hours 2 hours
6 hours @ 375 ⁰F 6 hours 6 hours
Post Cure – 6 hours
@ 475 ⁰F
6 hours N/A
Recommended Cure steps VS. Actual Cure steps performed by ENSC 22
Panels after the
envelope and curing
supplies were
removed
POST-MANUFACTURING The condition of the
panels shipped to
GU (from Janicki)
TESTING PROCEDURE 1) Place thermocouples on
front and back of coupon
2) Connect thermocouples to
LabVIEW
3) Position and center test face of
coupon 4-inches away from burner
exhaust
4) Calibrate burner using Fluke
meter thermocouple. Keep
burner cover on
5)Upon completion of calibration,
remove burner cover to expose
coupon to flame
6) Start timer and begin running
LabVIEW continuously
7) Let test run for at least 5
minutes. Use Fluke meter
thermocouple to ensure flame
temp is at least 2000°F
8) After test has run for at least 5
minutes, turn off burner to end
test. Stop running the LabVIEW
VI
9) Record all observations via
pictures, descriptions, and/or
videos. Extract LabVIEW data
10) Repeat steps 1-9 for all
remaining coupons
NOTE: In event of test
failure of coupon, turn
off burner to end test
immediately.
• (x4) OMEGA ® Nextel Ceramic Insulated Type K Thermocouples, 14 gage
(XC-14-K-12) for front face of coupons:
• (x4) OMEGA ® Precision Fine Bare Wire Type K Thermocouples, 0.010-inch diameter (CHAL-010) for back face of coupons:
• 1-inch thick ceramic fiber kaowool fire blanket for burner cone, burner cover, and coupon insulation:
• Phenolic board to support back side thermocouples:
• Ceramic bricks to support burner cone and coupons:
TESTING MAIN EQUIPMENT
DEVIATIONS FROM FAR IN TESTING
• The coupons are not 12”X12” plates – vary in size, depth, and surface profile .
• Burner used in the test was an oxy-acetylene torch airflow and heat flux varied from the FAR requirement.
Could still reach and maintain temperature of 2000ºF.
• Burner was made out of 1-inch thick kaowool and steel wire ties rather than inconel
• Test stand used ceramic blocks to prop up coupons and burner. The burner was also made stationary by use of a sheet metal base.
• A phenolic board was used behind coupons to support thermocouples on back side.
• Kaowool was used on edges of coupons in last 3 tests as insulation to prevent burn-around.
TESTING SETUP
4 bare-wired, lower
temp thermocouples
5-8 protruding
through phenolic
board, touching back
of coupon
Phenolic
board
Ceramic bricks
Fluke meter
thermocouple
Coupon
Burner cover for
calibration
Burner cone
Kaowool insulation
• Thermocouples were connected to a
DAQ which relayed data to LabVIEW
4 insulated, high temp
thermocouples 1-4 draped
over coupon
TESTING CALIBRATION
• Fluke meter was used to
calibrate burner
• Burner cover with kaowool
shield was placed over
burner
• Prevented panels from
burning during
calibration
• Burner cover was lifted to
begin test
TESTING
Coupon 1 Coupon 2
Coupon 3
DATA
Coupon 1 Coupon 2
Coupon 3
NOTE: “Temp. 2”
thermocouple, which
exceeded 2000°F, burned
off during Coupon 3 test
• Video evidence of Fluke-meter
thermocouple exceeding 2000°F
exists, to support conclusions
UNIVERSITY OF CINCINNATI RENEGADE MATERIAL TEST
TESTING RESULTS
Coupon 1 Coupon 3 Coupon 2
PHASE 1 CONCLUSIONS
Coupon w/ S2 fiberglass
prepreged w/ RM-3004 BMI skin The coupons with S2 fiberglass prepreged w/ RM-
3004 BMI as a protective skin PASSED the FAR
25.867 test by exhibiting no burn-through when
subjected to a 2000ºF flame for 5 minutes.
In conclusion, the S2 fiberglass prepreged w/ RM-3004
BMI skin is:
• A VIABLE SOLUTION for Boeing to use on its aircrafts
to pass the FAR 25.867.
• EASILY IMPLEMENTABLE, as the manufacturing/layup
process is very similar to that of the fiberglass prepreg skin
that Boeing currently uses.
Also note that S2-glass has a lighter density more heat
resistive than E-glass:
• S2-glass density = 0.0889 lb/in3 Softening Temp. = 1932°F
• E-glass density = 0.0932 lb/in3 Softening Temp. = 1554°F
The RM-3004 BMI prepreg resin density is 0.0452 lb/in3.
The resin content in our prepreg was 38 ± 3%
BUDGET ***Does not include ~$850 RM Shipping Cost/Trip to Boeing***
Original projected budget = $4800
PHASE 2
• Initial goal was to find solution that was more lightweight and/or inexpensive than current solution
• Needed to meet TDS
1. Build Requirements
2. Stress Requirements
3. Environmental Requirements
4. Cost Requirements
PHASE 2 BACKGROUND
HM Hinge Moment
HL Hinge Line
dx Distance from spoiler hinge line to LE of spoiler
Csp Spoiler Chord Length
P Pressure
Ssp Spoiler Aerodynamic Area
PHASE 2 RESEARCH HISTORY POTENTIAL SOLUTIONS • Polyurethane Foams
• Carbon Fiber Panels
• Metal Foams
• Aluminum Honeycomb
PHASE 2 RESEARCH HISTORY POLYURETHANE FOAMS General Plastics Manufacturing Company makes aerospace-grade rigid polyurethane foams (FR-6700 rigid foam series)
Advantages
1. Claims to be flame retardant, highly resistive to water absorption, inert to chemicals, and possess high strength-to-weight ratio
2. FR-6710 is lightest in the series, with density of 10 lb/ft3 and properties as seen in table
3. Could use to replace certain sections of honeycomb core
Disadvantages
1. Would make honeycomb manufacturing more difficult and expensive
2. Implementation change required would be drastic and costly
FR-6710 (Density = 10 lb/ft3)
Property
English Metric
Tensile Strength (psi) (kPa)
Parallel to Rise 303 2088
Perpendicular to Rise 307 2114
Shear Strength (psi) (kPa)
Rise Parallel to Specimen Width 239 1650
Rise Parallel to Specimen Thickness 254 1751
Shear Modulus (psi) (kPa)
Rise Parallel to Specimen Width 2823 19465
Rise Parallel to Specimen Thickness 3195 22032
Flexural Strength (psi) (kPa)
Rise Parallel to Test Span 480 3308
Rise Parallel to Beam Thickness 406 2800
Flexural Modulus (psi) (kPa)
Rise Parallel to Test Span 14017 96645
Rise Parallel to Beam Thickness 11449 78938
Water Absorption (lb/ft2) (kg/m2)
0.049 0.238
PHASE 2 RESEARCH HISTORY CARBON FIBER PANELS
• Carbon fiber panels cannot be directing bonded to the spoiler’s aluminum skins due to Galvanic Corrosion.
• Carbon fiber is still an expense product that can not rival the inexpensive of aluminum honeycomb panels.
• Carbon fiber bonded assemblies would increase manufacturing costs of the spoiler.
PHASE 2 RESEARCH HISTORY METAL FOAMS
• Fairly new technology
• Applications: sound absorbers & thermal
insulation
• Advantages: lower density, cost
• Manufacturing:
• Compact-powder foaming
• 5 stages: making the precursor, initial pore
formation, pore inflation, foam
degradation, and solidification
• Disadvantage:
• Monitoring metal foam formation
• Physical properties
PHASE 2 RESEARCH HISTORY ALUMINUM HONEYCOMB
• HexWeb® Aluminum Flex-Core Commercially available aluminum
honeycomb core specifically designed for formability
Retains mechanical properties in sharp curvatures
Offers cost savings for curved panels
CHARACTERISTICS UNITS
Current
Solution
5056/F80 -
6.5
Aluminum
Flex Core
Compression Strength psi 810 1500
Compression Modulus psi 227520 310000
Longitudinal Shear Strength psi 486 645
Longitudinal Shear Modulus psi 100080 73000
Transverse Shear Strength psi 297 420
Transverse Shear Modulus psi 47970 24000
Density lb/ft^3 6.9 6.5
• Advantages:
Light Weight
Low Cost
High Strength
• Disadvantages Potential corrosion in salt-water
Contact with carbon skins may cause galvanic corrosion
PHASE 2 ACTION PLAN ANSYS Simulation
• Separate SolidWorks spoiler model into its solid body constituents.
• Using the appropriate material properties located in the decision matrix, designate a material for each solid body. (Core properties, facing skin properties, material characteristics of spar elements, etc.)
• Convert individual SolidWorks part files into ANSYS part files.
• Reassemble the spoiler in ANSYS.
• Simulate the loading conditions provided and analyze results.
PHASE 2 ACTION PLAN Business Case
• Brief summary of alternative designs that were explored.
• Compare performance of current design and proposed solution.
• Include cost analysis detailing how the proposed solution is more cost efficient in regards to raw material cost, money saved with weight reduction, and manufacturing expenses.
• Goal: The proposed solution will meet the load requirements while reducing the weight and cost of the spoiler.
• Prediction: An alternative aluminum honeycomb with a lower density and lower cost is the best option for improving upon the current design while still meeting the load requirements.
• Rationale: The high strength/weight ratio of aluminum honeycomb is currently unrivaled by other core materials such as composites and foams.