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

Research output: Contribution to report/book/conference proceedingsIn-proceedings paper


Institutes & Expert groups

  • Tractebel - Engie
  • VSB-Technical University of Ostrava

Documents & links



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
Publication statusPublished - Oct 2018
Event2018 - ASME Pressure Vessels & Piping Conference - Hilton, Prague, Czech Republic
Duration: 15 Jul 201820 Jul 2018


Conference2018 - ASME Pressure Vessels & Piping Conference
CountryCzech Republic
OtherPromoting Excellence in the Global Pressure Vessel and Piping Industry Join us in Prague, Czech Republic for a the ASME Pressure Vessels & Piping Conference (PVP). More than 180 paper and panel sessions are planned, as well as tutorials, a Technology Demonstration Forum, and the 25th Rudy Scavuzzo Student Paper Symposium and Competition. The ASME 2018 PVP Conference promises to be the outstanding international technical forum for participants to further their knowledge-base by being exposed to diverse topics, and exchange opinions and ideas both from industry and academia in a variety of topics related to Pressure Vessel and Piping technologies for the Power and Process Industries. The PVP Conference is a great place to exchange ideas and to meet colleagues as we all work to create and advance Pressure Vessels and Piping technologies for our global community of practice. The PVP Conference is a recognized forum for fruitful exchange of ideas with participants from over 40 countries in Europe, Africa, the Middle East, Asia, the Americas, and the Oceania islands.
Internet address


  • Fracture toughness, Geometry, Engineering simulation, Steel, Pressure vessel, Hydrogen

ID: 6739009