National Institute of Technology, Rourkela

1. Role of Composites for gradual improvement of Aircraft Structure Presented By: AjitBehera Roll no- 210MM1248 National Institute of Technology, Rourkela

2. Contents • Background • Why composite preferable for Aero-structure ? • Use of Major Composite in Boeing Airplanes • Different stresses acting on an aircraft • Decline of Cost/weight by Composite • Conclusions • References National Institute of Technology, Rourkela

3. Background • Until the 1930’s, wood was the primary material used in aircraft construction. It was plentiful and cheap, had large bulk and strength for its weight, and could easily be worked into any desired shape. • Later, the first planes were built with combined construction of wood, fabric, steel and small amounts of aluminum for reinforcement. Manufactures used ash and spruce for the wings which were usually built around two I-shaped spars, and braced either by internal cables or by forming the leading-edge surface with ply. • Seamstresses applied to covering the wings with linen, cotton, or sometimes silk. • After World War-I, builders made the transition for the biplane configuration to monoplanes. Among the many structural improvements of this time were the monocoque fuselage and better metals. In this way demand of composite gradually increased…. National Institute of Technology, Rourkela

4. Why composite preferable for Aero-structure ? • Weight reduction • Challenge in cost reduction • Reduces / Eliminates corrosion • Increases in fracture toughness • Lightning protection • Improvements in fatigue resistance • damage tolerance limit increases • Structural integrity (To carry the damage part load without harming other parts and operation). National Institute of Technology, Rourkela

5. Major Composite Componentson Boeing Airplanes National Institute of Technology, Rourkela

6. Sress-Strain graph of typical aero-composite materials Carbon fiber+Fiber glass composite Fiber glass composite Strain Stress National Institute of Technology, Rourkela

7. Use of Composites in different Commercial and Military aerocraft At Different Time in Year National Institute of Technology, Rourkela

8. Principal structural units on Boeing 787 National Institute of Technology, Rourkela

9. Composite application on Boeing 787 Airframe National Institute of Technology, Rourkela

10. Different stresses acting on an aircraft (E) BENDING (THE COMBINATION STRESS) National Institute of Technology, Rourkela

11. Some Typical Failures • Inter-laminar Failure / Delamination / Disbond • Stress concentration such as hole, fillet, also deteriorate strength. It needs additional thickness= weight • Bolted joint is also a weak point on composite structure • Impact Damage strength regression National Institute of Technology, Rourkela

12. Some Structural Design Details Causing Local Stress Concentration and Redistribution • Bolted joints • Doors and windows • System provisions (penetrations and attachments) • Access and drain holes • Attachment tabs • Stringer terminations (run-outs) • Bonded attachments National Institute of Technology, Rourkela

13. Decline of Cost structure by Composite • Reduction in fuel Cost- Composite contributes light weight than that of bulk metal and Light weight structure contributes low fuel consumption. • Maintenance cost- Maintenance cost decreases due to less Body ideal time (Repairing time), increase in Change interval of Corroded parts & fractured parts, guarantee for longer inspection interval etc. For Boeing787 National Institute of Technology, Rourkela

14. Past Milestones for Composite Safety & Certification Policy, Guidance & Training National Institute of Technology, Rourkela

15. Recent Milestones for Composite Damage Tolerance and Maintenance Initiatives National Institute of Technology, Rourkela

16. Continue to Future milestones for Composite Safety & Certification Guidance and Training National Institute of Technology, Rourkela

17. Conclusions • The application of composite indicates optimal set of minimum structural weight and manufacturing cost. • However, exposed aircraft surfaces made from composite materials can prevent problems with respect to its hostile surrounding atmosphere. • Many investigations have been going on for evolution of new composite material for future aero-craft structure. National Institute of Technology, Rourkela

18. References [1]Yin Hailian, Yu Xiongqing, Integration of Manufacturing Cost into Structural Optimization ofComposite Wings, Vol. 23, Issue 6, 2010, 670-676 [2] Hui Juan Feng, Jian Zhang, Xiang Kai Liu, Applied Mechanics and materials, Vol. 121-126, 1264-1268, 2012. [3] Ronald F. Gibson, Principles of Composite Material Mechanics, 3rd edition, crc-press, Taylor & Francis Group, 53-87, 2012. [4] book review, Glare: History of the development of a new aerocraft Material, http://composite.about.com/od/books/l/aafpr020623.htm [5] Joosung Joseph Lee, Historical and Future Trends in Aircraft Performance, Cost, and Emissions, at the Massachusetts Institute of Technology September 2001. [6] Alex B. Harman, Chun H. Wang, Improved design methods for scarf repairs to highly strained composite aircraft structure, Vol. 75, Issue 1-4, 132-144 , 2006. [7] Soderquist, J., "Design/Certification Considerations in Civil Composite Aircraft Structure," SAE Technical Paper 871846, 1987, doi:10.4271/871846. [8] R. Kaye, M. Heller, Finite element-based three-dimensional stress analysis of composite bonded repairs to metallic aircraft structure, Vol. 26, Issue 4, 261-273, 2006. National Institute of Technology, Rourkela

19. Thank you for your attention. National Institute of Technology, Rourkela