STP876: A Modified Free-Edge Delamination Specimen

    Whitney, JM
    Materials Research Engineer, Materials Laboratory, Air Force Wright Aeronautical Laboratories, Wright-Patterson Air Force Base, OH

    Knight, M
    Materials Research Engineer, Materials Laboratory, Air Force Wright Aeronautical Laboratories, Wright-Patterson Air Force Base, OH

    Pages: 17    Published: Jan 1985


    Abstract

    An experimental approach to delamination fracture is presented which utilizes a free-edge delamination tensile coupon containing starter cracks in the form of embedded strips of material. These strips are embedded along the free edges of the laminate at the midplane. The purpose of the starter cracks is to promote Mode I interlaminar fracture behavior. Energy release rates are determined for various initial crack widths in conjunction with AS-4/3502 graphite/epoxy laminates with the stacking geometry [±30/∓30/902]s. These results are compared with energy release rates determined from a standard free-edge delamination coupon. The data reduction scheme is derived from a classical laminated plate theory analysis, including thermal residual stresses, of the test specimen.

    Keywords:

    composite materials, interlaminar fracture, strain-energy release rate, free-edge delamination, edge delamination, test (EDT)


    Paper ID: STP36311S

    Committee/Subcommittee: D30.04

    DOI: 10.1520/STP36311S


    CrossRef ASTM International is a member of CrossRef.