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An Improved Methodology for Measuring the Interfacial Toughness of Sandwich Beams

  • Qida Bing
  • Barry D. Davidson

Abstract

Existing interfacial toughness tests are evaluated for their accuracy and suitability for application to a wide range of sandwich structures and environments. It is shown that geometric nonlinearities and/or axial load coupling can cause errors in the perceived toughness as obtained by many of these tests and their associated data reduction methods. A previously proposed modified peel test is selected to eliminate the effect of axial load and a new, modified beam theory based method of data reduction is developed. Experiments and nonlinear finite element analyses are used to show that this approach produces highly accurate values of toughness, even in the presence of geometrically nonlinear behaviors. Mechanically attached loading tabs are described, allowing the test to be used for a wide variety of structures under various simulated usage environments.

Keywords

Crack Length Energy Release Rate Face Sheet Interfacial Toughness Data Reduction Method 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgment

This work was supported by the Office of Naval Research under Contract N00014-07-1-0418, Dr. Yapa D.S. Rajapakse, Program Manager.

References

  1. 1.
    Prasad S, Carlsson LA (1994) Debonding and crack kinking in foam core sandwich beams –II Experimental investigations. Eng Fract Mech 47(6):825–841CrossRefGoogle Scholar
  2. 2.
    Carlsson LA, Matteson RC, Aviles F, Loup DC (2005) Crack path in foam cored DCB sandwich fracture specimens. Compos Sci Technol 6:2612–2621CrossRefGoogle Scholar
  3. 3.
    Grau DL, Qiu XS, Sankar BV (2006) Relation between interfacial fracture toughness and mode-mixity in honeycomb core sandwich composites. J Sandwich Struct Mater 8:187–203CrossRefGoogle Scholar
  4. 4.
    Matteson RC, Carlsson LA, Aviles F, Loup DC (2005) On crack extension in foam cored sandwich fracture specimens. In:Thomsen OT et al. (eds.), Sandwich structures 7:Advancing with sandwich structures and materials, 7th edn., Springer, The NetherlandsGoogle Scholar
  5. 5.
    Smith SA, Emmanwori LL, Sadler RL, Shivakumar KN (2000) Evaluation of composite sandwich panels fabricated using vacuum assisted resin transfer molding. In:Proceedings of the 43rd international society for the advancement of material and process engineering conference, Anaheim, CAGoogle Scholar
  6. 6.
    Smith SA, Shivakumar KN (2001) Modified mode-I cracked sandwich beam (CSB) fracture test. In:Proceedings of the 42nd AIAA/ASME/ASCE/AHS/ASC Structures structural dynamics and materials conference, Seattle, WAGoogle Scholar
  7. 7.
    Shivakumar KN, Smith SA (2004) In situ fracture toughness testing of core materials in sandwich panels. J Compos Mater 38(8):655–668CrossRefGoogle Scholar
  8. 8.
    Shivakumar KN, Smith SA (2002) Influence of core density and facesheet properties on debond fracture strength of foam core sandwich composites. In:Sun CT, Kim H (eds.), Proceedings of the American society for composites 17th technical conference, West Lafayette, INGoogle Scholar
  9. 9.
    Shivakumar KN, Chen H, Smith SA (2005) An evaluation of data reduction methods for opening mode fracture toughness of sandwich panels. J Sandwich Struct Mater 7(1):77–90CrossRefGoogle Scholar
  10. 10.
    Kolat K, Neser G, Ozes C (2007) The effect of sea water exposure on the interfacial fracture of some sandwich systems in marine use. Compos Struct 78:11–17CrossRefGoogle Scholar
  11. 11.
    Li X, Carlsson LA (1999) The tilted sandwich debond (TSD) specimen for face/core interface fracture characterization. J Sandwich Struct Mater 1(1):60–75CrossRefGoogle Scholar
  12. 12.
    Viana GM, Carlsson LA (2003) Influences of foam density and core thickness on debond toughness of sandwich specimens with PVC foam core. J Sandwich Struct Mater 5:103–118CrossRefGoogle Scholar
  13. 13.
    Majumdar P, Srinivasagupta D, Mahfuz H et al. (2003) Effect of processing conditions and material properties on the debond fracture toughness of foam-core sandwich composites. Compos Part A:Appl Sci Manuf 34:1097–1104CrossRefGoogle Scholar
  14. 14.
    Li X, Weitsman YJ (2004) Sea-water effect on foam-cored composite sandwich lay-ups. Compos Part B:Eng 35:451–459CrossRefGoogle Scholar
  15. 15.
    Truxel A, Aviles F, Carlsson LA et al. (2006) Influence of face/core interface on debond toughness of foam and balsa cored sandwich. J Sandwich Struct Mater 8:237–258CrossRefGoogle Scholar
  16. 16.
    Cantwell WJ, Davies P (1994) A test technique for assessing core-skin adhesion in composite sandwich structures. J Mater Sci Lett 13:203–205CrossRefGoogle Scholar
  17. 17.
    Cantwell WJ, Davies P (1996) A study of skin core adhesion in glass fiber reinforced sandwich materials. Appl Compos Mater 3:407–420CrossRefGoogle Scholar
  18. 18.
    Ratcliffe J, Cantwell WJ (2000) A new test geometry for characterizing skin-core adhesion in thin-skinned sandwich structures. J Mater Sci Lett 19(15):1365–1367CrossRefGoogle Scholar
  19. 19.
    Ratcliffe J, Cantwell WJ (2001) Center notch flexure sandwich geometry for characterizing skin-core adhesion in thin-skinned sandwich structures. J Reinf Plast Compos 20(11):945–970CrossRefGoogle Scholar
  20. 20.
    Gates TS, Su X, Abdi F et al. (2006) Facesheet delamination of composite sandwich materials at cryogenic temperatures. Compos Sci Technol 66:2423–2435CrossRefGoogle Scholar
  21. 21.
    Cantwell WJ, Scudamore R, Ratcliffe J, Davies P (1999) Interfacial fracture in sandwich laminates. Compos Sci Technol 59:2079–2085CrossRefGoogle Scholar
  22. 22.
    Cantwell WJ, Broster G, Davies P (1996) The influence of water immersion on skin-core debonding in GFRP-balsa sandwich structures. J Reinf Plast Compos 15(11):1161–1172Google Scholar
  23. 23.
    Carlsson LA, Sendlein LS, Merry SL (1991) Characterization of face sheet/core shear fracture of composite sandwich beams. J Compos Mater 25:101–116Google Scholar
  24. 24.
    Shipsa A, Burman M, Zenkert D (1999) Interfacial fatigue crack growth in foam core sandwich structures. Fatigue Fract Eng Mater Struct 22(2):123–131CrossRefGoogle Scholar
  25. 25.
    Sundararaman V, Davidson BD (1997) An unsymmetric double cantilever beam test for interfacial fracture toughness determination. Int J Solids Struct 34(7):799–817CrossRefGoogle Scholar
  26. 26.
    Rybicki EF, Kanninen MF (1977) A finite element calculation of stress intensity factors by a modified crack closure integral. Eng Fract Mech 9:931–938CrossRefGoogle Scholar
  27. 27.
    Davidson BD, Sun X (2006) Geometry and data reduction recommendations for a standardized end notched flexure test for unidirectional composites. J AS™Int 3(9):1–19Google Scholar
  28. 28.
    Broek D (1986) Elementary engineering fracture mechanics. 4th rev. edn., Kluwer, Dordrecht, The NetherlandsGoogle Scholar
  29. 29.
    Hashemi S, Kinloch AJ, Williams JG (1990) The analysis of interlaminar fracture in uniaxial fibre-polymer composites. Proc R Soc Lond 427:173–199CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Qida Bing
    • 1
  • Barry D. Davidson
    • 1
  1. 1.Department of Mechanical and Aerospace EngineeringSyracuse UniversitySyracuse13244

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