Dynamic modeling of cleavage crack propagation and arrest with a local approach

Abstract

The assessment of reactor pressure vessels, usually based on crack initiation, could be completed using the crack arrest concept. The methodology classically recommended in safety codes and standards does not take into account the dynamic effects which are very important in crack arrest phenomena. To overcome this difficulty, a local crack arrest criterion has been recently proposed by some of the authors, for cleavage crack propagating in a low alloy bainitic steel: the crack propagates since the largest principal stress reaches a critical stress that depends on temperature. This study deals with the modeling of crack arrest experiments performed on A533-C1.B type steel with this criterion. Crack arrest was obtained on CT under isothermal conditions at –150°C and –125°C. The crack arrest criterion was identified with 2D computations. The application of this criterion shows that the crack propagation versus time leads to a good prediction of the crack speed and of the crack length.