Abstract
The concept of the local approach is applied to different damage mechanisms of structural steels by micromechanical material models. Static and dynamic fracture resistance curves for a neutron-embrittled weld material are derived from tensile and Charpy-type specimens with the modified Gurson model. The behaviour of a test piece with a crack in the ferri tic base material beneath an austenitic cladding could well be predicted. A constitutive model for creep and creep rupture was developed, implemented in a finite element program and applied to tests on a 12 per cent Cr steel. The model is a combination of the viscoplastic Robinson model and a damage mechanics model. It is formulated with internal variables for isotropic and kinematic hardening and with a scalar damage parameter. The application of the model to modified C(T) specimen with different hole diameters shows a good agreement between the predictions and the experiments.