Numerical verification of the Bridgman model for notched and unnotched round specimens

The aim of this work is to evaluate the accuracy of the Bridgman model for stress distributions on the neck of a cylindrical bar, and to compare its results with the corresponding values obtained using finite element analysis. The application of Bridgman's laws to an experimental data set allowed the definition of a constitutive curve, adopted as input for the FE models. Some of the numerical results obtained were compared with the corresponding experimental data, other FEM results were compared to the Bridgman prediction applied to the same experimental data. By this comparative analysis it was possible to evidence that a part of the experimental-numerical disagreement was due to the difficulty of taking damage evolution into account in the FE analysis. For a qualitative evaluation of this aspect, therefore, a new numerical comparison was made between the FEM results and a Bridgman prediction now based on the same FEM results (in terms of instantaneous load, contraction and profile curvature) instead of on experimental data as in the previous case.