Effect of anvil profile on cutting characteristics of polystyrene bar subjected to wedge indentation

Abstract

This research was aiming to investigate cutting characteristics of Polystyrene (PS) 3 mm square bars subjected to indentation of a center bevel (blade angle of 42°) steel blade and stacked on an AL anvil (underlay). To reveal the effect of contact width of workpiece against the anvil on the sheared edge profile of workpiece, the contact width was varied from 1 mm to 40 mm during the cutting test. In this process, the cutting load response was investigated and the sheared edge profile of workpiece was observed by a microscope. To discuss the effect of the anvil width on the deformation behavior of workpiece, a finite element method (FEM) analysis with elasto-plastic plain strain model was developed using a crack generation rule. Through the experiment and FEM analysis, a proportion of wedge penetration flow and crack propagation of sheared workpiece was revealed with the contact width. The peak maximum cutting force, pre-crack position and the breaking position were characterized with the contact width. When the contact width was two times or much larger than the thickness of workpiece, the wedge penetration flow form was remarkably appeared, while the crack propagation based smooth flat form was appeared when the contact width was narrower than the thickness of workpiece. A bent-down or bent-up deformation of workpiece varied with the contact width and its sign change occurred when the contact width was about two times of the thickness of workpiece. When choosing the narrower contact width than the thickness of workpiece, an asymmetric crack propagation occurred due to the misalignment of blade position against the left and right side edges of anvil.

Keywords

• shear
• cutting
• elasto-plastic
• fem
• square bar
• anvil
• crack