Finite element damage modeling in bending processes

The paper describes a 3D finite element modeling of air-bending process allowing for the prediction of the damage evolution during the forming operation. The numerical simulation of the damage evolution has been modeled by means of continuum damage approach. A damage model accumulation based on the Rice and Tracey ductile fracture criterion allowing for the description of the exponential dependence on triaxiality has been implemented into a finite element code. The mechanical state of the workpiece determined by the material properties variation in the domain of the bending arc such as the hardening and damage states as a result of the increase in strain toward the inner and outer surfaces in the bending arc.