STP696: Liquid Crystals for Flaw Detection in Composites

    Charles, JA
    Assistant Professor, The Ohio State University, Columbus, Ohio

    Pages: 11    Published: Dec 1979


    Abstract

    Liquid crystals have been investigated as an inexpensive nondestructive testing (NDT) technique for composite materials. By imaging the surface temperature distribution on both cyclically loaded and unloaded materials, subsurface flaws are found to be detectable. For specimens under load, likely damage locations and subsequent damage development can be determined. Cut fibers, inclusions, and geometric discontinuities served as flaws. Fiber glass/epoxy and graphite/epoxy composites were tested. It was found that liquid crystals can be used as an alternative to other NDT methods in many cases.

    Keywords:

    composite materials, fiber glass, graphite, nondestructive tests, thermal testing, liquid crystals


    Paper ID: STP36025S

    Committee/Subcommittee: D30.04

    DOI: 10.1520/STP36025S


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