The influence of thermal shock on inter-laminar shearing strength of woven C/C composites

Authors: Fukuda, Hiroshi; Itohiya, Go; Watanabe, Jun; Takahashi, Jun; Kemmochi, Kiyoshi

Source: Advanced Composite Materials, Volume 9, Number 2, 2000 , pp. 145-159(15)

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Abstract:

Although the mechanical properties of carbon fiber reinforced carbon (C/C) composites under high temperature environments have been widely studied to date, the influence of thermal shocks on C/C composites have scarcely been investigated due to the lack of high-speed heating equipment. Our equipment based on a high frequency induction heating method provided a solution to this problem. In the present study, we examined the influence of thermal shocks on the inter-laminar shearing strength (ILSS), which is one of the most important subjects of designing a plain woven C/C composite with a three point bending test. By the change of the span-to-height ratio (l/h), the failure mode shift of the inter-laminar shearing to the bending was observed. By a series of tests, we proposed an appropriate l/h ratio to obtain a reliable inter-laminar shearing strength of C/C composites, which would be higher than that for the conventional CFRPs. The observation of the failure specimens was done by scanning electron microscopy (SEM) and optical microscopy. Not only debondings at 0°/90° interface but also propagation of transverse cracks were observed in the thermal shocked specimens. The 0°/90° interfacial debondings were suggested as the main source of the inter-laminar shearing strength deterioration.

Keywords: C/C composites; woven fabric; thermal shock; three-point bending; interlaminar shearing strength; fractography; damage mechanism

Document Type: Regular paper

DOI: http://dx.doi.org/10.1163/15685510051029291

Publication date: 2000-06-01