1. peeling of composite sandwich structure(c.s.s )

2. Group presenter and supervisor SUPERVISOR : DR ZAHURIN BINTI HALIM PRESENTER : 1) NURUL NAJWA AHMAD 0822450 2) SITI NORAINI KAWAEED 0724126 3) MOHD BUKHARI YAHYA 0827361

5. Problem statement Weak joints between an outer metal sheet and the core of sandwich assemblies. Fracture toughness of the facesheet bond. Crack defects

6. introduction A composite sandwich structures: 1) special class of composite materials 2) fabricated by attaching two thin but stiff skins to a lightweight but thick core.

8. bonded between the facings of sandwich construction

9. in order to separate the facings.

11. COMPOSITE SANDWICH STRUCTURE WITH GRID STIFFENED CORE[VENKATA DINESH MUTHYALA,2005]

13. Sandwich panel foam

14. Honey comb sandwich

15. Sandwich panel

16. PROCEDURETEST Problems on the sandwich structure has been identified from the problem statement: One of them is poor bonding face problem In order to solve that problem, Climbing drum peel test is used in this case.

17. Peeling of C. S. S.

18. Continue..

20. Peeling test Climbing drum peel fixture for ASTM D1781 This test method covers the determination of the peel resistance of a sandwich structure and its core

22. Continue.. -Advantages Evaluate strength of skin-core -Disadvantages Difficult if the sandwich skin’s is too thin or too thick

23. application Railway floors, doors, interiors, fairing panels Boat hulls and interior panels and furniture Racing car chassis and body panels Specialist flight cases Helicopter blades Aircraft engine structures Aircraft doors and hatches Aircraft floor panels Racing car structures and aerofoils Energy absorbers

25. Ship and automotive

26. Discussion

28. Use suitable core.

29. Honeycomb is one of good core for composite sandwich structure.

31. Structural repair If the damage has weakened the structure through fibre fracture, delamination or disbonding the repair will involve replacement of the damaged fibre reinforcement, and core in sandwich structures to restore the original mechanical properties. Since a bonded-on repair constitutes a discontinuity of the original plies, and therefore a stress raiser, structural repair schemes normally require extra plies to be provided in the repair area. If the damaged area is very small it can be questionable whether a structural repair is required but more preferable to a cosmetic repair

32. Patch repair In this case the thickness of the original laminate is made up with filler plies and the repair materials are bonded to the surface of the laminate. Advantages > Quick and simple to do >Requires minimum preparation Disadvantages >A repaired laminate is thicker and heavier than the original >Very careful surface preparation is needed for good adhesion

33. Conclusion

34. conclusion Peeling is one of the major problem in the c.s.s. It can be prevent by applying good fiber, matrix and resin. It can be tested using Climbing drum peel fixture

35. REFERENCES www.sandwichpanels.org/articles/article_whatisasandwich.html http://jcm.sagepub.com/content/38/10/805.abstract http://www.com-ten.com/climbing-drum-peel-fixture-astm-d1781.html The American Heritage® Dictionary of the English Language, Fourth Edition copyright ©2000 by Houghton Mifflin Company Collins English Dictionary – Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003