Damage dependent stress limit model for failure prediction in bulk forming processes

Stress limit, combined with deformation and orientation dependent damages, is proposed as the criterion for failure prediction in bulk forming processes. Dedicatedly designed experiments are carried out to investigate this model. The results verify the existence of the stress limits. The value of stress limit can vary in different directions due to the material processing histories. The experiments revealed also strong kinematical hardening behaviours for the investigated material. The constitutive law has to include this effect to evaluate the stresses with sufficient precision.