A general mixed mode fracture mechanics test specimen: The DCB-specimen loaded with uneven bending moments

Bent F. Sørensen, K. Jørgensen, T.K. Jacobsen, R.C. Østergaard

    Research output: Book/ReportReport

    1184 Downloads (Pure)

    Abstract

    A mixed mode specimen is proposed for fracture mechanics characterisation of
    adhesive joints, laminates and multilayers. The specimen is a double cantilever
    beam specimen loaded with uneven bending moments at the two free beams. By
    varying the ratio between the two applied moments, the full mode mixity range
    from pure mode I to pure mode II can be generated for the same specimen geometry. The specimen allows stable crack growth. In case of large scale crack
    bridging, mixed mode cohesive laws can be obtained by a J integral based approach. As a preliminary example, fracture of adhesive joints between two
    glass-fibre laminates was studied. The mixed mode fracture resistance increased
    with increasing crack length due to fibre cross over bridging, eventually reaching a steady-state level (R-curve behaviour). The steady-state fracture toughness
    level increased with increasing tangential crack opening displacement. Cohesive
    stresses were determined by a J integral approach. The deducted shear stress
    was found to be relative high (≈ 20 MPa) in comparison with the normal stress
    (≈ 1 MPa).
    Original languageEnglish
    Place of PublicationRoskilde
    PublisherRisø National Laboratory
    Number of pages35
    ISBN (Print)87-550-3186-2
    ISBN (Electronic)87-550-3187-0
    Publication statusPublished - 2004
    SeriesDenmark. Forskningscenter Risoe. Risoe-R
    Number1394(EN)
    ISSN0106-2840

    Keywords

    • Risø-R-1394
    • Risø-R-1394(EN)

    Fingerprint

    Dive into the research topics of 'A general mixed mode fracture mechanics test specimen: The DCB-specimen loaded with uneven bending moments'. Together they form a unique fingerprint.

    Cite this