Etude et modelisation de la resistance a la rupture sur des eprouvettes entaillees

Abstract

The presence of geometric discontinuities in mechanical components induces a non-uniform stresses distribution. These discontinuities locally generate stress concentrations which can therefore cause premature failure if it is not properly taken into account in the design of the mechanical components. The parameters undergo variations going to the ruin of mechanical systems or structures. To take into account the factors that come into play, a study was carried out to analyze the variation of the angle and radius of notch on the notch stress intensity factor r I K and the plastic region in the vicinity of notch root. A specimen CT made in steel with different notch under a uniform tensile loading has been considered as finite element model. The considered approach is a local approach defined by the volumetric approach. The parameters of the volumetric approach i.e. the effective distance, effective stress and relative stress gradient are calculated from the finite element method under Castem software. Application of the volumetric approach in the case of elastoplastic behaviour has made it possible to realize the changing effect of the notch parameters. The results obtained are confronted to the models of Irwin and Creager - Paris.