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Analysis of defect toxicity by the K-beta method for elliptical or semi-elliptical defects located under the lining of pressurized water reactor tanks.

The objective of this method is to evaluate on a healthy mesh (without mesh defects) and in post-treatment of a mechanical study (axisymmetric or 3D) in linear elasticity, the intensity factor of the elasto-plastic stresses at the level of each of the two points of the defect, that is to say at the level of the tip on the coating side and at the level of the tip on the base metal side. The quantities obtained at the output of this method can then be used to subsequently determine the margin factors with respect to failure by comparison with the critical toughness of the failure mode envisaged at the level of the peak of the defect in question.

POST_K_BETA first calculates the elastic stress intensity factor at the two points of the defect, using the stresses at the nodes from the mechanical resolution and the residual stresses given by the user. Then, in a second step, the operator calculates the plastically corrected stress intensity factor from its elastic equivalent via the so-called « beta correction » method. This method is specific to under-coating defects that are stuck at the interface or slightly offset (coating side or base metal side) with respect to the interface and makes it possible to take into account the influence on the defect of the plasticization phenomenon occurring at the level of the tip on the coating side and the tip on the base metal side [R7.02.10].

Produces a table_sdaster concept.