Material Forces in Consideration of Phase Transformation in TRIP-steel

The phase transformation in austenitic TRIP-steels contributes to favourable mechanical properties and may affect their fracture behavior. Therefore, the influence of the phase transformation on the crack driving force is investigated. The concept of material forces is applied to a casted CrMnNi TRIP-steel by incorporating inelastic material and transformation behavior via the material model. The resultant material force expression for the near tip crack driving force is presented and evaluated by summing up nodal material forces. The advantage of this method is the separated calculation of material forces due to dissipation by plastic deformation and phase transformation as well as the material force acting directly at the crack tip. The TRIP-effect implies a considerable contribution to the material forces, i.e. the driving force for crack propagation is reduced, which indicates a shielding effect.