A FRACTURE MODEL APPLIED TO THE DUCTILE BRITTLE REGIME/

The fracture resistance of ferritic steels in the ductile/brittle tran sition regime is controlled by the competition between ductile tearing and cleavage fracture. Under typical conditions, a crack initiates an d grows by ductile tearing but ultimate failure occurs by catastrophic cleavage fracture. In this paper the tearing process is simulated usi ng void-containing cell elements embedded within a conventional elasti c-plastic continuum. Weakest link statistics is incorporated into the cell element model and this new model is employed to predict the onset of unstable cleavage fracture. Load-displacement behavior, ductile te aring resistance and transition to cleavage fracture are investigated for three different test geometries. The model predicts trends in duct ile/brittle transition that are consistent with experimental data.