Chapter 28. Investigation of Fiber/Matrix Interfacial Mechanical Behavior in Ceramic Matrix Composites by Cyclic Fiber Push-In Testing

  1. John B. Wachtman Jr.
  1. J. I. Eldridge1,
  2. R. T. Bhatt1,
  3. N. P. Bansal1 and
  4. F. A. Olmstead2

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314876.ch28

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4

How to Cite

Eldridge, J. I., Bhatt, R. T., Bansal, N. P. and Olmstead, F. A. (1996) Investigation of Fiber/Matrix Interfacial Mechanical Behavior in Ceramic Matrix Composites by Cyclic Fiber Push-In Testing, in Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314876.ch28

Author Information

  1. 1

    NASA Lewis Research Center, Cleveland, OH 44135

  2. 2

    Case Western Reserve University, Cleveland, OH 44106

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 1996

ISBN Information

Print ISBN: 9780470375433

Online ISBN: 9780470314876

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Keywords:

  • cyclic fiber push-in testing;
  • interfacial frictional sliding stresses;
  • continued push-in load cycle;
  • matrix interface;
  • cyclic fatigue behavior

Summary

Cyclic fiber push-in testing is used to examine the stability of interfacial factional sliding stresses and fiber debond lengths with continued push-in load/unload cycles. The measured response to applying load cycling to a single fiber reveals the susceptibility of the fiber/matrix interface to degrade under cyclic loading conditions, and thus, helps evaluate the contribution of the interface to the cyclic fatigue behavior of the composite after the occurrence of matrix cracks. From cyclic push-in testing in room temperature air, decreasing interfacial sliding stresses and increasing debond lengths are observed with continued load cycling for SCS-6 SiC fiber reinforced reaction-bonded silicon nitride (SCS-6/RBSN), whereas stable interfacial sliding stresses and no increase in debond lengths are observed with continued load cycling for SCS-6 SiC fiber reinforced strontium aluminosilicate (SCS-6/SAS). These results indicate that fiber-bridged matrix cracks should be stable under cyclic fatigue loading conditions in SCS-6/SAS, but should exhibit increasing crack opening displacements and fiber pull-out with continued cycling in SCS-6/RBSN. In addition, changing the test environment from room air to nitrogen significantly affects the cyclic push-in test results for SCS-6/RBSN, but not for SCS-6/SAS. The different responses to this change in test environment are attributed to different locations of interfacial failure.