Ductile rupture of A508 steel under nonradial loading

Abstract This study deals with the effect of loading path on the strain to failure of a C-Mn-Ni-Mo steel. The tests are carried out at 373 K on axisymmetric, notched tensile specimens calculated by the finite element method. Specimen geometries containing different notch radii and leading to widely different stress triaxiality ratios are investigated. The effect of nonradial load path is studied using relatively sharply notched specimens. It is shown that a simple linear damage rule does not account for the experimental results. A model based on the critical cavity void growth rate calculated from the Rice and Tracey model is shown to give results consistent with the experiments provided that the effect of prestrain on constitutive equation and on the stress triaxiality ratio is properly taken into account. The experimental results are also compared to a model based on continuum damage mechanics.