STP1274: Analysis of Mode III Delamination Fracture Testing Using a Midplane Edge Crack Torsion Specimen

    Li, J
    National Research Council research associate, NASA Langley Research Center, Hampton, VA

    Wang, Y
    Associate professor, School of Textile and Fiber Engineering, Georgia Institute of Technology, Atlanta, GA

    Pages: 16    Published: Jan 1996


    Abstract

    A shear deformation theory is used to analyze the edge crack torsion (ECT) specimen for Mode III interlaminar fracture testing. The theory is based on an assumed displacement field and the principle of virtue work. Mode II interference due to bending-twist coupling in general symmetric laminates is identified. The effects of free-edge delamination on the torsional stiffness and total strain energy release rate of a family of symmetric laminates containing 0, 90, and ±45 layers are studied. Favorable layups for the Mode III interlaminar fracture toughness characterization are recommended. Effective procedures for the determination of minimum torsional stiffness to initiate Mode III delaminations are established.

    Keywords:

    composite materials, laminated composites, fracture toughness, delamination, strain energy release rate, torsional stiffness, testing, design


    Paper ID: STP16544S

    Committee/Subcommittee: D30.06

    DOI: 10.1520/STP16544S


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