Session: CS-21-01 Constraint Effects on C&S

Paper Number: 106100

106100 - Consideration of Geometrical Effect in Fracture Mechanics Assessment for a Vessel Low Alloy Steel 

Numerous fracture tests have been performed by both EDF and Framatome on various specimen geometries extracted from a 18MND5 low alloy ferritic steel plate, in the brittle-to-ductile transition regime. C (T) , SEN (T) , SEN (B) , and non - standard specimens have been tested .

This work highlights a robust identification methodology which allows the prediction of constraint effect with minor consequences of the choices of the model formulation (classic model , consideration of stress threshold , or consideration of plastic strain … ) and on m parameter on the final interpretation .

Results demonstrate geometrical effects, resulting in shifting K_IC values of most specimens to higher values than those obtained on C (T) specimens, and the capability of the proposed model to predict correctly the experimental results .

The final goal of this work is to propose a methodology applicable in Engineering Fracture Mechanics Assessment to gain margins without considering any probabilistic consideration in the evaluation  : the procedure provides an equivalent crack tip loading corresponding to the situation of a standard C (T) specimen at the origin of the codified material toughness properties or an evalaution of the increased  toughness properties corresponding to the considered defect geometry.

 

Presenting Author: Stephane Marie Framatome

Presenting Author Biography: to be provided later

Authors:

Jules Louerat FRAMATOME
Olivier Ancelet FRAMATOME
Stephane Marie Framatome
Stephane Chapuliot EDF
Anna Dahl EDF