Ductile Fracture Simulation of Structural Steels under Monotonic Tension

Abstract

This paper aims to predict ductile fracture of mild steel under monotonic loading only from the test results of notchless tensile coupons. A simple fracture model based on the concept of a damage index with only one model parameter is proposed to predict ductile fracture of structural steels. The model is based on an idea of a combination of the void growth model and Miner’s rule in incremental form. Moreover, a new method to modify the true stress-true strain data after necking initiates is proposed, and it is found that the hardening modulus of several structural steels after necking initiates is approximately the same. Finally, ductile fracture of smooth and notched steel specimens is numerically simulated for three types of structural steels, which proves simplicity and acceptable accuracy of the fracture model and the modification method of the true stress-true strain.