Research on material deformation in double-sided shearing with preventing enlargement of sheet material on the die using digital image correlation

Abstract. In shearing, the effect of preventing the enlargement of sheet material on increasing burnished surface was reported. In this study, double-sided shearing with a suppression plate for preventing the enlargement of sheet material was carried out to investigate the effect of preventing the enlargement of sheet material on the material deformation and crack initiation. During shearing, the material deformation was observed using high speed camera and the distribution of displacement and strain of material were determined from moving images using digital image correlation. The following results were obtained from the observation of the cut surface obtained by shearing and the material deformation during shearing. When the suppression plate prevented the enlargement of the sheet material, the occurrence of cracks in the sheet material around the punch and die cutting edge was delayed. The length of burnished surface increased. For the same reason, the length of burnished surface increased as the trimming allowance of the sheet material was decreased when the enlargement of sheet material was prevented. It was confirmed that preventing the enlargement of sheet material affects the material flow. It is clarified that the equivalent strain around the punch and die cutting edge until crack initiation was increased when the enlargement of sheet material was prevented.