Predicting ductile fracture in ferrous materials during tensile tests using an ellipsoidal void model

An ellipsoidal void model was used to predict ductile fracture in ferrous materials during notch tensile testing. Simulated and experimental tensile tests were performed using four types of ferrous sheets and bars. The sheets and bars were prestrained to two different magnitudes by rolling and drawing, respectively. Six notched sheet specimens and thirteen notched bar specimens with different notch-root radii were prepared. The calculated results for the effects of prestrain and the initial notch-root radius on the reduction in area were found to agree with the experimental results. The assumption of plane stress for the case of a sheet, which was adopted in a previous study, was determined to be inappropriate. With increasing carbon content in the material, void nucleation was found to depend less on the equivalent strain and more on the triaxiality of the stress. The simulation results calculated using a void shape based on a representative volume element are not significantly different from those calculated using a conventional void shape. (C) 2017 Elsevier Ltd. All rights reserved.