Analysis of sheared edge quality in rotary blanking process based on Lemaitre damage model

To accurately describe the material degradation process from elastoplastic deformation to final rupture, an elastoplastic constitutive model was established to feature damage and crack initiation. A user-defined material subroutine VUMAT was developed, based on the Abaqus/Explicit platform, and its reliability was validated with an example. The damage parameter values were determined in cyclic loading-unloading tensile tests, using the Young's modulus weakening method. To predict the sheared edge quality, a finite element model of rotary blanking coupling with a Lemaitre damage model was built and the numerical results were compared with experimental results. The influences of blanking clearance, die wear and sheet metal thickness on the sheared edge quality, blanking force and torque were investigated. The results show that the sheared edge quality of the leading cutting edge is generally better than that of the trailing cutting edge, but the burnish depth of the leading cutting edge tilts at an angle. The rollover is larger, as is the die clearance. There is an extreme increase in the burr height when the degree of die wear is higher. The highest blanking force and torque values increase as the sheet metal thickness increases.