STP1128: Ultrasonic Imaging of Delamination Damage around Fastener Holes in a Graphite/Epoxy Composite

    McRae, KI
    NDE scientist; major, Canadian Armed Forces; group leader, Composites Group; and Captain, Canadian Armed Forces, Defence Research Establishment Pacific, Forces Mail Office, Victoria, BC

    McCray, AG
    NDE scientist; major, Canadian Armed Forces; group leader, Composites Group; and Captain, Canadian Armed Forces, Defence Research Establishment Pacific, Forces Mail Office, Victoria, BC

    Russell, AJ
    NDE scientist; major, Canadian Armed Forces; group leader, Composites Group; and Captain, Canadian Armed Forces, Defence Research Establishment Pacific, Forces Mail Office, Victoria, BC

    Bowers, CP
    NDE scientist; major, Canadian Armed Forces; group leader, Composites Group; and Captain, Canadian Armed Forces, Defence Research Establishment Pacific, Forces Mail Office, Victoria, BC

    Pages: 17    Published: Jan 1992


    Abstract

    Matrix cracking and multiple level delaminations around fastener holes in aircraft composite components can be associated with the overtorquing of fasteners. The damage can be repaired using a resin injection procedure. To determine the effectiveness of the procedure, an improved ultrasonic imaging technique was developed. The basis of this improved ultrasonic imaging technique is the acquisition of ultrasonic data that represent a three-dimensional volume of the specimen in the region surrounding the fastener. Because delaminations near the outer surface will obscure those located deeper within the specimen, two data sets, one from each surface, were collected from the specimen, deconvolved with respect to the transducer impulse response, and combined to form a more complete unified ultrasonic image. Using this image, a precise determination of delamination depth and area was accomplished by creating a series of C-scan images. The ultrasonic images obtained were compared to metallographic data and their correlation with the restoration of strengths and stiffnesses discussed.

    Keywords:

    composite materials, delaminations, fasteners, C-scans, ultrasonic imaging, ultrasonics, Wiener deconvolution, nondestructive evaluation


    Paper ID: STP14573S

    Committee/Subcommittee: D30.07

    DOI: 10.1520/STP14573S


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