manufacturing and design of lightweight composite … · uav-net meeting n.2 capua (italy), 11-12...

UAV-NET Meeting N.2 Capua (Italy), 11-12 February 2002

Manufacturing and Design of LightweightComposite Airplane Structures.

PART I - TECHNOLOGY Prof. Eng. Giulio ROMEO – Dr. Eng. Giacomo FRULLA

POLITECNICO DI TORINO(TURIN POLYTECHNIC UNIVERSITY),

Dept. of Aerospace Eng.; e-mail: [email protected]. Duca degli Abruzzi 24, 10129 TURIN, Italy

Phone: +39.011564.6820 - Fax +39.011564-6899

DIASP HELIPLAT

HELIPLATManufacturing of Composite Structures

Several military aircrafts, UAVs or business airplanes have been manufactured in these last twentyyears by using advanced composite materials. Mainly because [Ref. 37, 39, 40] :•Excellent physical & mechanical properties: - Low density -Very High Stiffness, Strength & Fatigue life along fibres direction. - Thermal expansion along fibres direction near to zero. - Resistance to corrosion.• Significant weight saving can be achieved by using composites instead of aluminium alloys.• Reduced part counts can be obtained with respect to metallic.•A stealth concept can be better achieved because the radar absorbent material properties.LIMITATIONS :• Reduced allowables because of impact damage (in graphite composite)• Reduced allowables in compression failure & transverse interlaminar stress (A-basis values).•Environmental effects:- maximum operating temperature (in epoxy matrix) - moisture absorption (mainly in aramidecomposite) - damage through lightning strikes or erosion with metal (in graphite).• Expensive Non Destructive Inspection method and Repair techniques. Costs.

• Mechanical properties are strongly directional;• Good design knowledge is than necessary to better exploit these advantages.

Manufacturing of Composite Structures

DIASP

GLOBAL HAWK

PREDATOR

HERON CENTURION

PATHFINDER

HELIPLAT

Microscopic scanning ofGRAPHITE/EPOXY


DIASP• The word composite describes a material where the interaction of two constituents (fibrousreinforcement + matrix) gives overall mechanical and physical properties of high efficiency.•Filament diameter: Glass-Carbon-Aramid:6-10 microns; Boron:140-200microns•Form: tows/rovings (without twist) or yarn: bundles of several hundred thousand of filaments.

[Ref. 41] [Ref. 37, 39, 24]


PAN-based:-First oxidation stage under stretch in air at 150-250°C-Carbonisation in nitrogen up to 1000-1500 °C or argon up to 2-3000°C

Two main precursors are mainly used:PAN (Polyacrylonitrile: CH2 = CH-CN)nPITCH (from oil or coal)

CARBON/GRAPHITE FIBRESDIASP

Depending from the heat-treatment temperature and from thestretch level during the first oxidation stage, the tensilestrength and tensile modulus of carbon or graphite fibres canhave values very different for each type.

[Ref. 42]Five different groups of carbon fibres -HS (High Strength) -VHS (Very High Strength) -IM (Intermediate Modulus) -HM (High Modulus) -VHM (Very High Modulus)

HELIPLAT

Manufacturing of Composite Structures Aramid fibres (ARomatic polyAMID)

Made by Dupont or by Akzo from para or meta aramid

® Dupont [Ref. 42]Boron fibres: Reaction of hydrogen and boron trichloride at 1250°C.Deposition of boron on an electrically heated tungstenwire, at very low speed (2-3 m/s) up to 0.14-0.2 mm.

Glass fibres: • Chemical structure of Silica (SiO2) + Oxides (Al2O3 & MgO)• Made by drawing from the melt above 750°C, at very highspeed (2-400 m/s).

Material Density[Kg/dm3]

Young'sModulus

[GPa]

TensileStrength[MPa]

Aramid/Epoxy 1.35 62 1600Boron/Epoxy 2.10 240 1800Carbon/Epoxy: UHM 1.80 415 1300 HM 1.65 240 1500 IM 1.60 180 2500 VHS 1.65 150 2200 HS 1.60 150 1500Glass/Epoxy 2.05 50 2200Aluminium Al 2.55-2.78 78-73 450-600Volume fraction 60% (Aramid fibres: 50%)

Mechanical Properties of UD composite materials

[Ref. 37, 39, 40]

DIASP

HELIPLATManufacturing of Composite Structures MATRIX

EPOXY RESIN: Thermosetting matrix. Reaction of epoxy group with hardener(diamine, dicyandiamided). No shrinkage, good bonding, chemically resistant.Limited ductility gives low damage tolerance, low hot/wet performances.As pre-preg (correct amount of resin, partially cured) has to be stored at -18°C.OPERATING TEMPERATURE LIMIT: 150°C

BISMALEIMIDE RESIN: Thermosetting matrix. Improved mechanical properties athigher temperature and under hot/wet conditions.OPERATING TEMPERATURE LIMIT: 230°C

POLYIMIDE RESIN: Very difficult preparation, handling & curing cycles (highvolatile).OPERATING TEMPERATURE LIMIT: 315°C

THERMOPLASTICS: Better Damage tolerance performances, environmentalresistance, fast processingOPERATING TEMPERATURE LIMIT: 150°C [Ref. 37, 39, 40]

DIASP HELIPLAT

Manufacturing of Composite Structures Vacuum Bagging Airtech

IROP Autoclave Parma - Italy

Diameter = 1.5m ; Length = 2m

[Ref. 27, 29, 31]

Autoclave curing

HELIPLAT


Tape winding or

Fibre placement

Filament winding


EFA - EUROFIGHTER

[Ref. 40]


DIASP

STAR SHIP [Ref. 45]


DIASP THERMAL EXPANSIONMOULDING TECHNOLOGY

[Ref. 28,29,33,38]


DIASP THERMAL EXPANSIONMOULDING TECHNOLOGY

Lockheed L-1011 Fin

Wing box

[Ref. 41,30,31,33]

HELIPLAT


DIASP HELIPLAT Tubular Technology

[Ref. 3,4,5,8]


HELIPLAT: CFRP Wing Box 21m LongDIASP

[Ref. 3,4,7,8,11]

HELIPLAT


DIASP CFRP WING BOX - 6m Long

[Ref. 11]


DIASP

Truss Structure Technology [Ref. 3,4,5,6,9]

HELIPLAT

Design of Composite Structures

DIASPQuadratic Failure Criterion:Fij �i�j + Fi �i �1

Fatigue behaviour

C/E UD Brittle Tensile failure

[Ref. 49]

MOISTURE ABSORPTION

[Ref. 42]

HELIPLATDIASP MOISTURE ABSORPTION


T=70°C & 95%RH

MOISTURE DESORPTIONT=60°C & Vacuum=10-3 Pa

UD 0°

FABRIC 0/90°

[Ref. 18,23,49]

HELIPLAT THERMAL EXPANSION TESTS

FABRIC 0/90°

UD 0°


DIASP

[Ref. 15,18,49]


DIASP HELIPLAT

P/Pu

Kinetic Energy J

Residual Failure Load after Impact

Visible-damage threshold

Failure threshold

Impact tests of carbon/epoxy atseveral impact energies

[Ref. 24]

HELIPLAT

Design of Composite Structures DIASP

BIBLIOGRAPHY1) ROMEO G., FERRERO G.: "Analytical/Experimental Behaviour of Anisotropic Rectangular Panels underLinearly Varying Combined loads". AIAA JOUR., Vol. 39, N.5, 2001, pp.932-941.2) ROMEO G.: "Analytical and Experimental Behaviour of Laminated Panels with Rectangular Opening underBiaxial Tension, Compression and Shear Loads". J. of COMPOSITE MATERIALS, Vol. 35, No. 8/2001,pp. 639-664.3) ROMEO G., FRULLA G., FATTORE L.: “HELIPLAT: High Altitude Very-Long Endurance SolarPowered UAV for Telecommunication Applications. FEM Analysis, Manufacturing and Testing of 21m longCFRP Wing Box”. APPLIED VEHICLE TECH. Panel Symposium on Unmanned Vehicles (UV) for Aerial,Ground & Naval Military Operations. Ankara (Turkey) Oct. 2000. RTO Meeting Proc.: MP-052, N.12.4) ROMEO G., FRULLA G., FATTORE L.: “ HELIPLAT: A Solar Powered HAVE-UAV forTelecommunication Applications. Design & Parametric Results. Analysis, Manufacturing & Testing ofAdvanced Composite Structures”. INT. TECHNICAL CONF. on ““UNINHABITED AERIAL VEHICLES.UAV 2000.. Paris, June 2000.Paris, June 2000.5) ROMEO G.: "Design of High Altitude Very-Long Endurance Solar-Powered Platform for EarthObservation and Telecommunication Applications". J. AEROTECNICA MISSILI e SPAZIO, Vol.77, N.3-4, July-Dec.98. pp. 88-99.6) ROMEO G., FRULLA G.: "Experimental Behaviour of Graphite/Epoxy Panels with Cut-outs under BiaxialTension, Compression and Shear Loads". 21st ICAS Congress, Melbourne, Sept. 1998. Paper A98-31588.7) ROMEO G.: "Manufacturing and Testing of Graphite-Epoxy Wing Box and Fuselage Structures for a Solar-powered UAV-HAVE". 21st ICAS Congress, Melbourne, Sept. 1998. Paper A98-31591.8) ROMEO G.: "HALE Solar-powered Platform for Earth Observation and Telecommunication Applications.XIV AIDAA Nat. Congress, Napoli, Oct. 1997. Vol. I, pp. 447-456.

HELIPLAT


BIBLIOGRAPHY9) ROMEO G.: "Design Proposal of High Altitude Very-Long Endurance Solar Powered Platform for EarthObservation and Telecommunication Applications". 48th Int. Astronautical Congress (IAF), October 1997,Turin. Paper n. IAF-97-M.2.05.10) ROMEO G., FRULLA G.: "Experimental Behaviour of Graphite/Epoxy Panels with Holes under BiaxialCompression and Shear Loads". 11th ICMM, Australia, July 1997. Vol. V, pp.635-644.11) ROMEO G.: "Design Proposal and Wing Box Manufacturing of a Self-launching Solar-poweredSailplane". XXV OSTIV Congress,. TECHNICAL SOARING, Vol.21, N.4, pp. 106-115, Oct. 1997.12) ROMEO G., FRULLA G.: "Post-Buckling Behaviour of Graphite/Epoxy Stiffened Panels with InitialImperfections Subjected to Eccentric Biaxial Compression Loading". INT. J. OF NON-LINEARMECHANICS, Vol.32, N.6, pp. 1017-1033, 1997.13) ROMEO G., FRULLA G.: "Post-buckling Behaviour of Graphite/Epoxy Wing Boxes Panels under PureTorsion". 20th ICAS Congress, Sorrento, Sept. 1996, Vol. I, pp.115614) ROMEO G., FRULLA G.: "Non-linear Analysis of Graphite/Epoxy Wing Boxes under Pure BendingIncluding Lateral Pressure". AIAA J. OF AIRCRAFT, Vol.32, N.6, Nov-Dec. 1995, pp. 1375-1381.15) ROMEO G., FRULLA G.: "Analytical and experimental results of the coefficient of thermal expansion ofhigh-modulus graphite-epoxy materials". J. COMPOSITE MATERIALS, Vol.29, No.6/1995, pp.751-765.16) ROMEO G., FRULLA G., BUSTO M.: "Influence of the incomplete diagonal tension field on the non-linear angle of twist of advanced composite wing boxes under pure torsion". AIAA J. OF AIRCRAFT,Vol.31, No.6, Nov-Dec. 1994, pp. 1297-1302.17) ROMEO G., FRULLA G.: "Non-linear analysis of anisotropic plates with initial imperfections, variousboundary conditions subjected to combined biaxial compression and shear loads". INT. J. OF SOLIDS &STRUCTURES, Vol.31, 1994, No.6, pp.763-783.

HELIPLAT


BIBLIOGRAPHY18) FORNARI B., DOSIO D., ROMEO G.: "Characterisation of a State of the Art UHM CFRP System forSatellite Application". Proc. of Int. Symposium on Advanced Materials for Composite Structures '94. ESTEC,Noordwijk (NL), March 1994. ESA-WPP-070, 1994, pp. 569-575.19) ROMEO G., FRULLA G.: "Post-buckling behaviour of anisotropic plates under biaxial com-pression andshear loads". Proc. 18th ICAS Congress, Beijing, P.R. China, Sept. 1992, Vol.2, pp.1936-1944.20) ROMEO G., FRULLA G.: "Analytical and experimental results of composite panels under combinedbiaxial compression and shear loads". J. AEROTECNICA, Vol.70, n.3-4, July-Dec. 1991, pp. 107-116.21) ROMEO G., ALONSO C., FRULLA G.: "Analytical and experimental comparison of graphite/epoxywing boxes under pure torsion". XI AIDAA Nat. Congress, Forlì, Oct. 1991, pp. 1504-1516.22) ROMEO G., FRULLA G.: "Buckling of simply supported and clamped anisotropic plates under combinedloads". Proc. Int. Conf. On Spacecraft structures and mechanical testing. ESA-ESTEC, Noordwijk, NL, April1991. ESA SP-321, Oct 1991, pp. 161-166.23) ROMEO G., MIRALDI E., RUSCICA G., BERTOGLIO F., RUVINETTI G., FRULLA G.: "A new testfacility for measuring the coefficient of moisture expansion of advanced composite materials". ASTM J. OFCOMPOSITES, TECHNOLOGY and RESEARCH, Vol.14, No.4, Winter 92, pp. 225-230.24) ROMEO G., GAETANI G.: "Effect of low velocity impact damage on the buckling behaviour of compo-site panels". Proc. 17th ICAS Congress, Stockholm, Sept. 1990, Vol.1, pp. 994-1004.25) ROMEO G., ALONSO C., PENNAVARIA A.: "Buckling of laminated cylindrical plates including effectsof shear deformation". Proc. of Int. Symposium on Space applications of advanced structural materials. ESA-ESTEC, Noordwijk, NL, March 1990. ESA SP-303, June 1990, pp. 365-370.26) ROMEO G., BARACCO A.: "Minimum-mass optimization of composite stiffened, unstiffened andsandwich curved panels subjected to combined longitudinal and transverse compression and shear loading".Proc. 7th ICCM, Guangzhou (P.R. China), Nov. 1989, Vol.3, pp. 364-370.

HELIPLAT

Design of Composite Structures DIASPBIBLIOGRAPHY

27) ROMEO G.: "Design, fabrication and experimental testing of an advanced composite truck frame". Proc.9th Int. SAMPE Conf., Milan, June 1988, pp. 211-236.28) ROMEO G.: "Analytical and experimental results of advanced composite stiffened panels undercombined loads". Proc. Workshop:Composite design for space applications, ESA-ESTEC, Noordwijk, NL,Oct. 1985. ESA SP-243, Feb.1986, pp. 79-86.29) ROMEO G.: "Experimental investigation on advanced composite stiffened structures under uniaxialcompression and bending". AIAA/ASME/ASCE/AHS 26th Structures, Structural Dynamics and MaterialsConf., Orlando, USA, April 1985. AIAA JOURNAL, Vol.24, n.11, Nov.1986, pp. 1823-1830.30) ROMEO G.: "Experimental results of advanced composite sailplane structures". Proc. XVIII OSTIVCongress, Hobbs, USA, July 1983. Publication XVII, pp. 84-86.31) ROMEO G.: "Sailplane wing box design by use of graphite/aramide/epoxy material". XVII OSTIVCongress, Germany, May 1981, TECHNICAL SOARING, n.2, Dec. 1981, pp. 70-75.33) ROMEO G., van DREUMEL W.: "Design and fabrication of an advanced composite cellular wing box".Delft Univ. Technology, Dept. Aerospace Eng., Rep. LR-315, 1981.32) ROMEO G.: "Design of hat-stiffened composite panels under uniaxial compression and shear. Minimummass optimization based on a simplified theory". Delft Univ. of Technology , Dept. Aerospace Eng., Rep.LR-312, 1981.34) ROMEO G.: "Analytical and Experimental Results of a graphite/epoxy truck frame under shear- bendingtests. Journal ATA (Associazione Tecnica dell'Automobile), Vol. 42, n.4, April 1989, pp. 235-242.35) ROMEO G., BARACCO A.: "Buckling Load of Several Types (Sandwich, Blade, T and Hat-stiffened)Cylindrical Composite Panels Subjected to Biaxial Compression and Shear Load as Typical Application to anAircraft Fuselage (Theoretical Analysis and User’s Manual of the Optimization Computer ProgramOPTICO)”. Politecnico di Torino, Dept. Aerospace Eng., TN n. 23, April 1989. (In Italian)36) ROMEO G., ALONSO C.: "Buckling of Cylindrical Laminated Plates under Biaxial Compression andShear Loads Computer Program ALPATAR” Politecnico di Torino Dept Aerospace Eng TN n 21 1989

HELIPLAT

Design of Composite Structures DIASPBIBLIOGRAPHY

37) ROMEO G.: "Technology of Advanced Composite Materials for the Manufacturing of Airplane Structures.Notiziario Tecnico AMMA, Anno XLII, n.6,1987, pp. 20-42. (In Italian)38) ROMEO G.: "Design and Manufacturing of Integral Composite Panels”. J. AEROTECNICA MISSILI ESPAZIO, Vol.62, n.1, March 1982, pp. 44-54.39) ROMEO G.: "Technology of Graphite/epoxy Materials and their Applications in the Aeronautical Industry.Journal INGEGNERIA, n.3-4 e 5-6, March and May 1980. (In Italian)40) D.H. MIDDLETON Editor: “Composite Materials in Aircraft Structures”, Longman Scientific &Technical, 1990.41) J.L. ETHELL: “Fuel Economy in Aviation”. NASA SP-462, 1983.42) “Practical Considerations of Design, Fabrication and Tests for Composite Materials,AGARD-LS124, 1982.43) J.F. SCHIER & R.J. JUERGENS: “They Force a Fresh Look at the Design Process”. Astronautics &Aeronautics, Sept. 1983, pp.44-49.44) M.A. DORNHEIM: “AeroVironment Pushes Limits of Solar Flight”, Aviation Week & Space Technology,May 4, 1998, pp.54-57.45) F. COLUCCI: “The Starship Enterprise”, Aerospace Composites & Materials, Vol. 1, No. 1, Autumn 1988,pp.12-16.46) J.M. WHITNEY: “Structural Analysis of Laminated Anisotropic Plates”, Technomic Publ. Co., 1987.47) J.N.REDDY: “Mechanics of Laminate Composite Plates: Theory and Analysis”. CRC, 1997.48) “Composite Design Handbook”, ESA-PSS-03-1101, 1986.49) G. ROMEO, G. FRULLA: “Experimental Test of Composite Structures”, Politecnico di Torino, Dept.Aerospace Eng., TN n. 21, 23, 49, 50, 65, 78, 79, 80, 96, 101. 1985-1998.50) G. ROMEO, G. FRULLA: “Design of UAV HELIPLAT Scaled-size Composite Structures”, Politecnico diTorino, Dept. Aerospace Eng., Helinet reports 13, 24, 34, 36, 71, 86, 87. 2000-01.

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