ADVANCED COMPOSITE MATERIALS 08/06/2022 New Technology composites 1 Used in construction on new technology aircraft and considerations in their use Péter Marosszéky FRAeS MIFA MAOPA (USA) Adjunct Senior Lecturer & Research Fellow University of New South Wales School of Aviation Faculty of Science
Advanced Composite materials. Used in construction on new technology aircraft and considerations in their use P éter Marosszéky FRAeS MIFA MAOPA (USA) Adjunct Senior Lecturer & Research Fellow University of New South Wales School of Aviation Faculty of Science. Introduction. - PowerPoint PPT Presentation
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22/04/2023 New Technology composites 1
ADVANCED COMPOSITE MATERIALS
Used in construction on new technology aircraft and considerations in their use
Péter Marosszéky FRAeS MIFA MAOPA (USA)Adjunct Senior Lecturer & Research Fellow
University of New South Wales School of AviationFaculty of Science
IntroductionThe areas that need to be
considered:• Occupational Health and Safety• Advanced composites • Damage tolerance and assessment• Repair Assessments• Repair schemes & processes• Specialized equipment & tooling• Approved MRO’s• Training
Health & Safety Hazards• Risks & hazards can be controlled• Use of MSDS data• A wide range of safety procedures
have been developed and approved• Current FAR 145.163 and EASA
Advisory Circular 65-33 requirements
• High overheads & retraining • Manufacturer programs ie:
Boeing’s “Gold Care” program
Advanced CompositesA range of advanced composites in use
on new generation aircraft• Two primary advanced composites are in
use on the Boeing 787 and the Airbus A350XB
• Boeing have opted for the Torayca 3900-series highly toughened carbon fibre-
reinforced epoxy prepreg – unidirectional tape (various widths) & narrow slit tape (for fibre replacement) and woven fabric forms Majority of the 3900 – series made from intermediate modulus T800S fibre.
Advanced Composites • Boeing continued: • The surface finishing provides
resistance against moisture and contaminant ingress: Cytec SurfaceMaster 905.
• A high-temperature bisaleimide composite material, that allows application & removal of paint without compromising the integrity of the sub-structure
Boeing 787 series
Boeing 787 continued• Other primary structures• Window frames & Engine Nacelles
use Hexcel HexMC trademarked as HexPly AS4 carbon fibre prepreg (350°C/177°F cure) 8552 epoxy prepreg resin (Nordam)
• Wing & Trailing edge components use Hexcel’s HexFlow RTM6 with Cytec Surface Master 905
• Some landing gear components utilize Hexcel IM-7 fibre.
Airbus A380 series • Primary structure:• Empennage – Carbon fibre reinforced
plastic (CFRP)• Fin leading edge – Glass fibre reinforced
Airbus A350XB series Airbus have selected the Hexcel
HEXPLY M-21E Carbon fibre toughened epoxy prepreg composite for primary
structures
Damage tolerance & assessment
• Advanced composites have Significant weight, stiffness and strength advantages over Aluminium
• Advanced composites are susceptible to damage with greater resistance than
Aluminium • Advanced composites are susceptible to
sunlight (infra-red) exposure, however pre-spun prepreg carbon fibre is less
affected due to the tight weave reducing surface area of resins/catalysts
Damage tolerance & assessment continued…• Boeing and Airbus tests have been
validated by the ASTMAdvanced Carbon fibre in use on the 787 and A350 has been certified to
allow continued airworthiness if impact contact does not leave a visible sign, no further action need be takenIf damage is visible then action must
be taken in accordance with the respective SRM (Structural Repair
Manual)
Damage tolerance & assessment continued…An example of the effects of damage and subsequent fatigue propagation, tests have shown that in tight weave carbon fibre a breach of the structure not exceeding 2.54cm/1.0in. Will not
propagate any furtherLarger areas of damage repaired and
processed in accordance with manufacturer specifications will have
permanent repair status.
Damage tolerance & assessment continued…
Airbus research and assessment (validated by (ASTM) has shown the
damage tolerance of GLARE is significantly better than Aluminium,
however not as resistant Carbon fibre prepreg
Damage tolerance & assessment continued
• Electrical and Fluid exposure damage.
• Electrical:• Advanced Carbon composites are
electrical conductors • Copper mesh is embedded in the
structure to provide for conductivity and earth return for electrical systems as the “earth return”
Damage tolerance & assessment continued…
• Fluid exposure:• Coatings applied during
manufacture provide protection against phosphate ester fluid (Hydraulic fluids) ingress
• Water and waste protection against ingress
• Corrosion is prevented by the use of Titanium fasteners
General & specific applications
Repair assessments• Considerations of damage
assessment• Area of damage• Location• Structural requirements• Type of material• Equipment and materials
available at location
Repair assessments continued…
• Repair must be in accordance with manufacturers SRM