Effect of mechanical conditions on cutting characteristics of polycarbonate sheet subjected to straight punch/die shearing

摘要

This paper aims to reveal cutting characteristics of a 0.5 mm thickness polycarbonate sheet subjected to a straight punch/die shearing. The punch/die clearance was varied to be 2 ～ 20% of the worksheet thickness. Also, the feed velocity of the punch was adjusted ranging from 0.05-1.0 mm-s~(-1). From experimental results, a crack initiated in the vicinity of a cutting tool corner was observed to be largely propagated into the bulk of the worksheet. This deviated propagation seemed to be affected by an in-plane/lateral unbalanced stress state in the worksheet. The variation of the feed velocity had almost no effect on the pattern of crack initiation and its propagation. In addition, the shearing problem was numerically studied by using a two dimensional FEM simulation to discuss about the crack propagation and the dependency of the cutting characteristics on the punch/die clearance.