Chapter 56. Fracture in Unidirectional Off-Axis Ceramic Matrix Composite

  1. J. P. Singh
  1. Alex S. Selvarathinam and
  2. Y. J. Weitsman

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294437.ch56

Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 18, Issue 3

Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 18, Issue 3

How to Cite

Selvarathinam, A. S. and Weitsman, Y. J. (1997) Fracture in Unidirectional Off-Axis Ceramic Matrix Composite, in Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 18, Issue 3 (ed J. P. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294437.ch56

Author Information

  1. Department of Mechanical & Aerospace Engineering & Engineering Science 307 Perkins Hall, University of Tennessee Knoxville, Tennessee-37996–2030

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1997

ISBN Information

Print ISBN: 9780470375495

Online ISBN: 9780470294437

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Keywords:

  • ceramic matrix composite;
  • multiple cracks;
  • eigen function expansion;
  • tensile stresses;
  • fiber-matrix interfaces

Summary

The present study focuses on multiple cracks that occur in uni-directionally reinforced CMC's (ceramic matrix composite) under tensile loads, with fiber oriented at an angle π/2-ϕ to the load direction. These composites were observed to develop fiber-bridged matrix cracks perpendicular to the load directions, with subsequent inclined extensions along the fiber-matrix interfaces. The foregoing fracture phenomenon is investigated analytically using a combination of a displacement based finite element scheme and an eigen function expansion method which establishes both near field and far field solutions. It is observed that when the matrix crack impinges on the inclined fibers, tensile stresses arise along the interface inclined at an angle ϕ and compressive stresses along the interface inclined at an angle ϕ-π. This result explains experimental observation where fractures were noted to evolve along fiber-matrix interfaces inclined at an angle ϕ to the direction of matrix crack. Computations were performed for SiC/CAS ceramic composite with ϕ=60°.