Numerical Simulation of Fine Blanking on Plane Blankholder

Fine blanking process on plane blank holder utilizes three tooling elements: a punch, a plane blank holder and an ejector to generate a highly compressive stress state and pure shearing forces to constraint the deformation of sheet metal within the narrow blanking clearance zone. Numerical simulation of fine blanking for steel 20 was performed using commercial FEM software DEFORM, and element deletion technology was used to model the initiation and propagation of crack. Besides, Normalized Cockroft&Latham ductile fracture model was taken into the prediction of the quality of shear surface. Material flow analysis was investigated with the respect to the blank holder and ejector force, and the influence of process parameters such as blanking clearance and die edge radius on shear surface was discussed in this paper. Thus, effect of blank holder and ejector forces on the material flow characteristics, the relationship between the process parameters and burnish zone ratio are revealed, which may be helpful to the development of fine blanking.