Development of a Simplified Approach for Using the Local Approach to Fracture

Abstract

Today there is a strong demand from different industries to use local fracture criteria in a simplified way. This paper presents the main results of a two years joint research project where CEA, EDF, School of Mines and IRSID were associated. A simplified method based on the Beremin models for cleavage and ductile fracture has been developed. This procedure can be used to evaluate the risk of fracture of industrial structures or to allow a rapid development of new materials. Finite element simulations were systematically performed for axisymmetrically notched tensile and precracked specimens using a parametric description of stress-strain laws. Results were presented in the form of graphs that can be used directly for measuring local fracture parameters from tests on axisymmetrically notched specimens and to predict fracture toughness. An additional parameter measuring the level of plastic constraint has been taken into account. This parameter can be easily evaluated on industrial structures. This allows a simple way of using local criteria to evaluate the safety of such structures.