Towards a Process for the Assessment of Mixed Mode I+II Fracture Toughness

Afaf Bouydo, Valéry Lacroix, Rachid Chaouadi, Vratislav Mares

    Research outputpeer-review


    In fracture mechanics, a flaw behavior in pressure vessels is assessed with respect to the material fracture toughness.
    Fracture toughness which most Fitness-for-Service (FFS) codes relies on, only considers mode-I crack opening. However, in presence of tilted flaws, like quasi-laminar hydrogen flakes, this mode-I toughness may be too severe, and a mixed mode I+II fracture toughness seems to be more appropriate.
    In order to address the assessment of the fracture toughness curve, mixed mode I+II tests were performed by the authors on ferritic steel samples by adjusting the standard mode I CT specimen geometry to a geometry subjected to mixed mode I+II. Then, XFEM simulations of the mixed mode tests were performed in order to calculate the J-integral along the crack front.
    Based on tests and calculations results, the paper explains how the authors work towards proposing a method to measure the material fracture toughness in case of flaws subjected to mixed mode (I+II) loading.
    Original languageEnglish
    Title of host publicationASME 2018 Pressure Vessels and Piping Conference
    Subtitle of host publicationVolume 1A: Codes and Standards
    Number of pages10
    StatePublished - Oct 2018
    Event2018 - ASME Pressure Vessels & Piping Conference - Hilton, Prague
    Duration: 15 Jul 201820 Jul 2018


    Conference2018 - ASME Pressure Vessels & Piping Conference
    Country/TerritoryCzech Republic
    Internet address

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