Blanking with pre-bending of steel sheets-experimental investigation and FEM simulation

Abstract EN

The accuracy of blanked parts can be characterized by the form errors, such as the presence of a fractured zone on the shearing surface and deflection.

Conventional blanking results in an approximately one-third smooth-sheared zone and a two-third fractured zone over the full workpiece thickness, and additionally usually the stamps show a curvature.

In order to delay the moment of material failure, and thus increase the stamp cutting surface quality, a new method of sheet blanking process is proposed.

After initial bending, during the punch movement a sheet blank is flattened, which causes compressive stresses in the sheared region.

In this investigation, the effect of pre-bending on both the stamp shearing surface quality and the part deflection were determined experimentally.

The MSC Marc 2001 package served for the FEM based simulation of the blanking process.

As a result it is indicated that the pre-bending of semi-products has a beneficial effect on both the sheared surface quality and the part deflection after blanking.

Key words: fine blanking, pre-bending, shearing surface quality, deflection.

Classification: Mechanical Engineering and Technology, Modeling of Metal Forming Processes, fine-blanking, pre-bending, stamp quality, steel sheet, experimental results, and computer simulation.