Evaluation of Fracture Toughness in C/C Composite under Four-Point Bending (Difference in Fabrication Method and Fracture Mechanism)

Hiroyuki Kawada, Makoto Matsumori, Hideo Omata, Tomoyuki Uruno, Jiro Hiramoto, Ikuhiko Hayashi

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To evalute fracture toughness of C/C composites, four-point bending tests (SEN) are performed. The C/C composites are carbonized from the CFRPs, which are fabricated by means of two different methods (a hot-press method and a vacuum-bagging one). It is found that each fabrication method leads to a different distribution of bending strength. The vacuum-bagging method is preferable to obtain uniform bending strength properties. Crack growth resistance curves are obtained based on the compliance matching method. These curves have an inclination of convergence at a nearly equal constant value regardless of fabrication method. Existence of the stress shielding mechanism in the C/C composites is suggested by the R curves. From a fractographic observation, crack propagates three-dimensionally, and then pullouts of the fiber bundle occur at a large scale in the fiber-bridging mechanism.

Original languageEnglish
Pages (from-to)978-983
Number of pages6
JournalTransactions of the Japan Society of Mechanical Engineers Series A
Issue number572
Publication statusPublished - 1994 Jan 1



  • C/C Composite
  • Crack Propagation
  • Crack Resistance Curve
  • Fracture Toughness
  • Mechanical Property

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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