B22 Deformation Analysis of Polycarbonate Sheet with Flexible Underlay During Wedge Cutting Process(Advanced machining technology)

Abstract

This paper reports on the cutting characteristics of a polycarbonate (PC) worksheet mounted on flexible underlays by wedge indentation. In order to investigate the effect of underlay stiffness on sheared profile of PC worksheet, an underlay stiffness in thickness direction ku was varied by introducing the ku=Eu/tu as the underlay Young's modulus Eu by the underlay thickness tu. Indentation of 42 degree center bevel blade into a 0.5mm thickness of PC sheet that mounted on flexible underlays was carried out experimentally and numerically. Cutting deformation of PC sheet was observed by a CCD camera in order to reveal the effect of underlay on the cutting performance of PC sheet. On the experimental works, we found that the underlay mechanical properties affected the cutting load response and deformation features of the PC sheet. To discuss the effect of underlay stiffness on the deformation profile of PC sheet, the finite element analysis (FEA) with elasto-plastic model was conducted. Through the experiment and FEM simulation, the followings were obtained: (i) the deformation profile of PC sheet remarkably depends on the stiffness ratio of underlays, when the stiffness ratio is less than a certain value. (ii) the separation of PC sheet was available when the stiffness is larger than a certain critical value. (iii) the flexible underlay contributes to enlarge the equivalent wedge angle due to sinking and bending of wedged PC sheet.