STP893: Characterization of Mode I and Mixed-Mode Failure of Adhesive Bonds Between Composite Adherends

    Mall, S
    Associate professor, University of Missouri, Rolla, MO

    Johnson, WS
    Research engineer, National Aeronautics and Space Administration, Langley Research Center, Hampton, VA

    Pages: 13    Published: Jan 1986


    Abstract

    A combined experimental and analytical investigation of an adhesively bonded composite joint was conducted to characterize both the static and fatigue debond growth mechanism under Mode I and Mixed-Mode I and II loadings. Two bonded systems were studied: graphite/epoxy adherends bonded with EC 3445 and FM-300 adhesives. For each bonded system, two specimen types were tested: (1) a double-cantilever-beam specimen for Mode I loading and (2) a cracked-lap-shear specimen for Mixed-Mode I and II loading. In all specimens tested, failure occurred in the form of debond growth. Debonding always occurred in a cohesive manner with EC 3445 adhesive. The FM-300 adhesive debonded in a cohesive manner under Mixed-Mode I and II loading, but in a cohesive, adhesive, or combined cohesive and adhesive manner under Mode I loading. Total strain-energy release rate appeared to be the driving parameter for debond growth under static and fatigue loadings.

    Keywords:

    composite materials, adhesive bonding, debond propagation, strain-energy release rates, fracture mechanics, fatigue (materials)


    Paper ID: STP35356S

    Committee/Subcommittee: D30.05

    DOI: 10.1520/STP35356S


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