In the frame of the Structural Integrity demonstration of the Doel 3 and Tihange 2 RPVs flawed with quasi-laminar cracks, alternative proximity rules based on 3D eXtended Finite Element Method (X-FEM) calculations have been developed by Tractebel Engineering. The calculations have been performed with the X-FEM software Morfeo Crack. This software uses the Level-Sets method allowing a very straightforward cracks modelling.
A large part of the development of these proximity rules for quasi-laminar flaws has been dedicated to the validation of the models and the calculations. This validation has been done through a benchmark with Engineering Mechanics Corporation of Columbus (Emc2). This company uses:
• The Finite Element Alternating Method (FEAM) for calculating stress intensity factors through the FRAC@ALT program. The FEAM is a state-of-the-art method for obtaining stress intensity factors for three-dimensional surface and embedded crack problems.
• The X-FEM functionality as implemented in Abaqus software.
The benchmark consists of the Stress Intensity Factor calculation of interacting quasi-laminar flaws and of the interaction factor assessment as well.