1. Introduction

The mechanics of elastic rupture, based on the classical criteria of energy restoration rate, contour integral \(J\) and stress intensity factor \(K\), does not make it possible, in general, to deal with problems in which plasticity plays an important role. In this case, which remains the domain of broad-ranging open research, other approaches must be put in place. In the case of proportional monotonic loading, approaches with 2 parameters, such as approaches \((J,Q)\) or \((K,T)\) ([1]), are generally satisfactory. Unfortunately, the field of validity of these approaches is limited to proportional loads.

This is why the mechanics of elasto-plastic rupture, which should make it possible to extend the validity of the mechanics of rupture, is being developed. The cleavage mechanism (with confined plasticity) is particularly one of its responsibilities.

The objective of this documentation is to provide methodological assistance in the use of elasto-plastic fracture mechanics models in the context of cleavage prediction. It does not in any way exempt you from reading the code_aster Reference and Usage documents relating to the models and commands referred to here.

The phenomenon of cleavage is initially quickly explained. The four models that can be used in code_aster, two probabilistic (Beremin and Bordet) and two deterministic (\({G}_{P}\) and Le Corre), are in turn described with aids to their respective use. Since these models are of the post-processing type of a thermo-mechanical calculation, it is appropriate for this calculation to be as reliable as possible, and therefore for precautions, as mentioned here, to be taken.