STP876: The Use of Stitching to Suppress Delamination in Laminated Composites

    Mignery, LA
    Mechanics and Materials Center, Texas A&M University, College Station, TX

    Tan, TM
    Assistant Professor, Drexel University, Philadelphia, PA

    Sun, CT
    Professor, School of Aeronautics and Astronautics, Prudue University, West Lafayette, IN

    Pages: 15    Published: Jan 1985


    Abstract

    The effect of stitching on edge delamination and ultimate strength in graphite/epoxy laminates is investigated. Study is done on three different graphite/epoxy layups: [±30/0]s, [±30/90]s, and [±45/02/902]s. Progression of delamination is monitored using di-iodobutane enhanced X-radiography. Results show that stitching effectively arrests delamination, but has varying effects on tensile strength. A two-dimensional finite element is used to calculate interlaminar normal stress and strain energy release rate for stitched and unstitched laminates. The introduction of stitching causes little change in interlaminar normal stress. However, it reduces the strain energy release rate as the delamination crack approaches the stitch line.

    Keywords:

    stitching, di-iodobutane (DIB), delamination, tensile strength, free-edge stress, strain energy release rate


    Paper ID: STP36315S

    Committee/Subcommittee: D30.04

    DOI: 10.1520/STP36315S


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